SPREADING ACQUISITION AND MEASUREMENT OF CAPACITY SENSORS AND RELATED SYSTEMS, METHOD AND DEVICES

Abstract

Capacitive sensing system, comprehensive: a sensor switching logic that includes detection lines and sensor channels; an acquisition switching logic that is operationally coupled with the sensor channels, wherein the acquisition switching logic is configured to receive captured signals from the sensor channels indicating one or more capacities at the sensor switching logic, and to provide accumulated spread-coded captured signals in response to the capture signals; and where the acquisition switching logic is configured: to spread-code each of the received captured signals for each channel by applying mutually orthogonal spreading codes, where each bit of a spreading code is either a logical zero or a logical one; and to accumulate spread-coded values ​​for each channel in response to one or more orthogonal spreading codes used to encode each channel; and a digital control system that is operationally coupled with the acquisition switching logic to determine a channel capacity measurement in response to the accumulated spread-coded values.

Description

PRIORITY CLAIM

[0001] This application claims the benefit of the filing date of the preliminary US patent application serial no. 62 / 688,254, filed on Thursday, June 21, 2018, for "Spread Measurement of Capacitance Sensors and Related Systems, Methods and Devices", and claims the benefit of the filing date of the pending US patent application serial no. 16 / 109,420, filed on Wednesday, August 22, 2018, for "Spread Acquisition and Measurement of Capacitance Sensors and Related Systems, Methods and Devices", which also claims priority over preliminary US patent application serial no. 62 / 688,254, the contents and disclosure of which are hereby incorporated in their entirety by reference. TECHNICAL AREA

[0002] Embodiments of the present disclosure generally relate to capacitive sensing and, more specifically, to spread acquisition and measurement techniques of sensing channels of capacitive sensors and related systems, methods and devices. STATE OF THE ART

[0003] A typical touch interface system may include touch sensors (capacitive, resistive, etc.) that respond to an object in close proximity to, or in physical contact with, a touch-sensitive surface of the touch interface system. The responses can be captured and interpreted to infer information about the contact, including a position on the interface. Touchpads used with personal computers, including laptops and tablet keyboards, often include or work in conjunction with a touch interface system. Displays often include touchscreens that incorporate elements (usually at least the touch sensor) of a touch interface system to allow a user to interact with a graphical user interface (GUI) and / or computer applications.Examples of devices that incorporate touch displays include portable media players, televisions, smartphones, tablet computers, personal computers, and wearable devices such as smartwatches, to name just a few. Furthermore, control panels for automobiles, appliances (e.g., an oven, a refrigerator, a washing machine, etc.), security systems, ATMs, home environment control systems, and industrial equipment can incorporate touch interface systems to activate buttons, sliders, and other touch elements, among other things.

[0004] The inventors of this disclosure understand that displays, devices, and humidity, for example, can introduce noise into a touch interface system, and noise coupling can cause undesirable counter-capacitance effects at the sensor and acquisition switching logic. Conventional touch interface systems may have other disadvantages and shortcomings.

[0005] US 2012 / 0182259A1 describes a method and apparatus for identifying the coordinates of a touch area on a touchscreen panel based on a capacitive scheme.

[0006] US 2012 / 0319988A1 describes a capacitive sensing method comprising sending an initial transmitter signal with a first transmitter electrode, wherein the initial transmitter signal comprises a plurality of sensing cycles.

[0007] US 2015 / 0 205 408 A1 describes a multi-channel acquisition system and a method for its operation.

[0008] US 2012 / 0056841A1 describes a touchscreen system comprising a capacitive touchscreen with a plurality of row conductors and a column conductor. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The purpose and advantages of the various embodiments of the disclosure will be apparent to a person skilled in the art from the detailed description in conjunction with the accompanying figures: Fig. Figure 1 shows a representative diagram of the operation of a touch system that includes acquisition and measurement techniques using simultaneous acquisition and spreading codes according to embodiments of the disclosure; Fig. Figure 2 shows a capacitive sensing system that incorporates coding techniques for acquisition and measurement according to embodiments of the disclosure; Fig. Figure 3 shows a representative diagram of the operation of a capacitive sensing system that includes acquisition and measurement techniques using simultaneous acquisition and spreading codes according to embodiments of the disclosure; Fig. Figure 4 shows a representative diagram of the noise tolerance during the operation of a capacitive sensor system, which includes acquisition and measurement techniques using simultaneous acquisition and spreading codes according to embodiments of the disclosure; Fig. Figure 5A shows a flowchart of a capacitive sensing acquisition process that includes spreading techniques, according to embodiments of the disclosure; Fig. Figure 5B shows a flowchart of a capacitive sensing acquisition process that includes spreading techniques, according to embodiments of the disclosure; Fig. Figure 6 shows a capacitive sensing system that incorporates coding and frequency spreading techniques in acquisition and measurement according to embodiments of the disclosure; Fig. Figure 7A shows a flowchart of a capacitive sensing acquisition process that includes coding and frequency spreading techniques, according to embodiments of the disclosure; Fig. Figure 7B shows a flowchart of a capacitive sensing acquisition process that includes coding and frequency spreading techniques, according to embodiments of the disclosure; Fig. Figure 8 shows a representation of a force detection process, according to one embodiment of the disclosure; and Fig. 9A and Fig. Figure 9B shows capacitive capture acquisition processes according to the state of the art. TYPE(S) OF IMPLEMENTATION OF THE INVENTION

[0010] The following detailed description refers to the accompanying drawings, which form part thereof and in which specific exemplary embodiments are shown for illustration, illustrating how the present disclosure can be put into practice. These embodiments are described in sufficient detail to enable a person skilled in the art to carry out the present disclosure. However, other embodiments may also be used, and changes to the structure, material, and process may be made without departing from the scope of the disclosure.

[0011] The illustrations shown herein are not intended to be actual views of any particular method or system, or of any particular device or structure, but are merely idealized representations used to describe the embodiments of the present disclosure. The drawings shown herein are not necessarily to scale. Similar structures or components in the various drawings may retain the same or similar numbering for the convenience of the reader; however, the similarity in numbering does not imply that the structures or components are necessarily identical in size, composition, configuration, or any other characteristic.

[0012] It is understood that the components of the embodiments, as generally described herein and illustrated in the drawings, can be arranged and designed in a wide variety of different configurations. Therefore, the following description of various embodiments is not intended to limit the scope of protection of this disclosure, but is merely representative of different embodiments. While the various aspects of the embodiments may be illustrated in drawings, the drawings are not necessarily drawn to scale unless expressly stated otherwise.

[0013] The following description may include examples to enable a person skilled in the art to carry out the disclosed embodiments. The use of the terms "by way of example", "as an example", and "for example" means that the accompanying description is explanatory, and while the scope of protection of the disclosure is intended to include the examples and their legal equivalents, the use of such terms is not intended to limit the scope of protection of any embodiment or of this disclosure to the specified components, steps, features, functions, or the like.

[0014] Therefore, the specific implementations shown and described are only examples and should not be interpreted as the only way to implement the present disclosure unless otherwise stated herein. Elements, circuits, and functions may be shown in block diagram form to avoid obscuring the present disclosure with unnecessary details. Conversely, the specific implementations shown and described are only examples and should not be interpreted as the only way to implement the present disclosure unless otherwise stated herein. Furthermore, block definitions and the partitioning of logic between different blocks are examples of a specific implementation. It is readily apparent to the person skilled in the art that the present disclosure can be implemented by numerous other partitioning solutions.Details concerning time considerations and the like have been largely omitted where such details are not necessary to obtain a complete understanding of the present disclosure and are within the capabilities of an average professional.

[0015] The information and signals described herein may be represented using various different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips referenced in the description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof. Some drawings may illustrate signals as a single signal for the clarity of the presentation and description. It should be apparent to the average person skilled in the art that the signal may represent a bus of signals, the bus being of a variety of bit widths, and the disclosure being implemented on any number of data signals, including a single data signal.

[0016] It is understood that any reference to an element in this document using a label such as "first," "second," etc., does not restrict the set or order of those elements unless such restriction is expressly stated. Rather, these labels are used herein as a convenient method for distinguishing between two or more elements or instances of an element. Thus, a reference to a first and second element does not mean that only two elements may be used, or that the first element must in any way precede the second element. Likewise, unless otherwise stated, a set of elements may comprise one or more elements.

[0017] Similarly, elements referred to in the singular form can sometimes also include one or more instances of the element.

[0018] The various illustrative logic blocks, modules, and circuits described in connection with the embodiments disclosed herein may be implemented or carried out using a general-purpose processor, a specialized processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof, designed to perform the functions described herein. A general-purpose processor (which may also be referred to herein as the host processor or simply the host) may be a microprocessor; alternatively, the processor may be any conventional processor, controller, microcontroller, or state machine.A processor can also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration. A general-purpose computer including a processor is considered a specialized computer, while the general-purpose computer is configured to execute computing instructions (e.g., software code) relating to embodiments of the present disclosure.

[0019] It is also noted that the embodiments can be described in terms of a process represented as a flowchart, flow diagram, structure diagram, or block diagram. Although a flowchart can describe operational processes as a sequential process, many of these processes can be performed in a different order, in parallel, or substantially simultaneously. Furthermore, the sequence of operations can be rearranged. A process can correspond to a method, thread, function, procedure, subroutine, subprogram, etc. Furthermore, the methods disclosed herein can be implemented in hardware, software, or both. When implemented in software, the functions can be stored or transmitted as one or more instructions or code on computer-readable media.Computer-readable media include both computer storage media and communication media, including all media that support the transfer of a computer program from one location to another.

[0020] As understood for the purposes of the embodiments described in this disclosure, a capacitive sensor can respond to the contact of an object (e.g., a finger or pen) with a contact-sensitive area of ​​the capacitive sensor or the object's proximity to it. In this disclosure, "contact" and "touch" are intended to include both the physical contact of an object with a contact-sensitive area and the presence of an object near a contact-sensitive area without physical contact. Actual physical contact with a capacitive sensor is not required.

[0021] When an object touches a capacitive sensor, a change in capacitance can occur within the touch sensor at or near the point of contact. An analog acquisition front end can "detect" the touch when it reaches a certain threshold. "Charge-then-transfer" is a technique implemented in some touch acquisition front ends, whereby a sensing capacitor is charged in response to the change in capacitance (e.g., charging faster or slower) and the charge is transferred to an integration capacitor over several charge-transfer cycles. The amount of charge associated with such a charge transfer can be converted into digital signals by an analog-to-digital converter (ADC), and a digital controller can process these digital signals to take measurements and determine whether an object has made contact with the sensor.

[0022] Self-capacitance sensors are capacitive field sensors that detect / respond to changes in capacitance to ground. They are typically arranged in an array of rows and columns that respond independently to touch. As a non-restrictive example, a self-capacitance sensor could include a circuit that uses repeating charge-and-transfer cycles with a common integrated CMOS push-pull driver circuit with floating terminals. Counter-capacitance sensors are capacitive field sensors that detect / respond to changes in capacitance between two electrodes: a drive electrode and a sensing electrode. The drive-electrode and sensing electrode pairs at each intersection of the drive and sensing lines form a capacitor.Self-capacitance and counter-capacitance techniques can be used in the same touch interface, and complementarily, for example, self-capacitances can be used to confirm a touch detected using a counter-capacitance.

[0023] Touch sensors can be superimposed in a two-dimensional (2-D) arrangement for a contact-sensitive 2-D surface, which can be integrated into a contact-sensitive surface, for example, a touchpad or a display screen, and can facilitate user interaction with an associated device. Insulating protective layers (e.g., resins, glass, plastic, etc.) can be used to cover touch sensors. As used here, a "touch display" or "touch panel" is a display (such as a liquid crystal display (LCD), a thin-film transistor LCD (TFT-LCD), or a light-emitting diode display (LED display)) that includes 2-D touch sensors.

[0024] Using the example of a touchscreen that employs a matrix sensor approach based on counter-capacitance sensors using charge transfer techniques, drive electrodes can extend in rows on one side of a substrate, and sensing electrodes can extend in columns on the other side of the substrate to define a "matrix" array of N × M nodes. Each node corresponds to an intersection between the electrically conductive leads of a drive electrode and a sensing electrode. A drive electrode simultaneously drives all nodes in a given row, and a sensing electrode senses all nodes in a given column.The capacitive coupling of the drive electrode and the sensing electrode (counter-capacitance) or the coupling of a sensing electrode and ground (self-capacitance) at a node position can be measured separately or together in response to a change indicating a touch event. For example, if a drive signal is applied to the drive electrode in row 2 and a sensing electrode in column 3 is active, then the node position is: (row 2, column 3). Nodes can be scanned by sequencing through various combinations of drive and sensing electrodes. In one mode, the drive electrodes can be driven sequentially while the sensing electrodes are all continuously monitored. In another mode, each sensing electrode can be scanned sequentially.

[0025] Some touch interfaces incorporate force sensing. Such "force-sensitive" interfaces may include sensors integrated into, for example, a display or touchpad to measure incremental differences in the distance between a surface and a feature beneath the surface. For instance, when relative movement occurs, the distance between an electrode pair may change, providing a measurable change in capacitance. This change in capacitance can be used to estimate a force applied to the "force-sensitive surface" in response to a magnitude of the capacitance change. The location of the applied force on the force-sensitive surface can also be estimated, for example, in response to one or more locations of electrode pairs of the force sensor that registered a change in capacitance, and / or a touch sensor also integrated into the interface.

[0026] As a non-limiting example, microcontrollers, digital logic circuits, and / or configurable state machines can be implemented to control the drive electrodes and analyze the capacitive effects on a touch sensor and a force sensor. Integrated circuit packages (IC packages) that include a microcontroller can provide the input and output connections for communication with a host, as well as the firmware for performing techniques and operations, including those described herein in connection with various embodiments. Examples of microcontrollers that can be used with the various embodiments of this disclosure may include, for example, peripheral interface microcontrollers, ARM-based microcontrollers, and AVR 8-bit and 32-bit microcontrollers.

[0027] For example, the sensing electrodes of a capacitive sensor can be operationally coupled to an acquisition front end (such as a charge integrator) via device I / O pins of a digital controller. The digital controller can be coupled to the acquisition front end via ADC / DAC pins. The digital controller can include, for example, a state machine (a collection of adders, flip-flops, and multiplexers that can form a digital logic circuit) configured to identify a contact and information about the contact in response to channel capacitance measurements.

[0028] In this disclosure, “simultaneous acquisition” and “acquired simultaneously” mean the acquisition of signals (analog or digital) that indicate detected signals from multiple (e.g., two or more) detection channels of a capacitive sensor during the same acquisition cycle, by analog switching logic and / or digital logic circuitry. The detected signals may be, for example, a charge flow from detection channels of a capacitive sensor to a sampling switching logic, a charge-to-voltage converter, or both. A measurable signal may be a voltage, a current, a resistance, a capacitance, or combinations thereof. The detected signals from multiple sensor channels may be acquired by the same acquisition switching logic or by more than one acquisition switching logic.The embodiments described in this disclosure assume that the acquired signals are acquired on the same acquisition logic, which, however, as mentioned above, is not a requirement of the disclosure. The use of the past tense "acquired" as in "acquired simultaneously" is not intended to require the completion of a simultaneous acquisition and can include any point in time or operation during a simultaneous acquisition.

[0029] Channel capacitance refers to both the absolute channel capacitance and a change in channel capacitance. A channel capacitance measurement, or capacitive measurement, includes any value that indicates a channel capacitance.

[0030] In this revelation, “spreading code” means an N-bit encoded data stream with a data rate (i.e., a frequency, which may also be called the encoding rate). The encoding rate is typically a multiple of N x the data rate of the data being encoded. In the digital domain, each bit of the spreading code is a logical “0” or a logical “1”. For example, an 8-bit spreading code might be “0101 0101”. For the sake of consistency and clarity, spreading codes are discussed in the digital domain, but they can also refer to analog signals with an amplitude and a frequency.

[0031] Some spreading codes can be orthogonal to other spreading codes, meaning the cross-correlation of the two spreading codes is essentially zero (i.e., they do not interfere with each other). A property of orthogonal spreading codes is that the dot product of the two spreading codes is zero.

[0032] A conventional capacitive measurement technique involves proceeding channel by channel, as in Fig. Figure 9A shows that measurements are performed sequentially for each of the channels 902, one acquisition channel at a time, with each cycle 904. Thus, channel 1 is measured in cycle 1, channel 2 in cycle 2, channel 3 in cycle 3, and channel 4 in cycle 4. The channel-by-channel measurement is fast (4 channels in 4 cycles), however, a low noise tolerance is built into the measurement process itself.

[0033] One technique for improving the SNR is to average multiple measurements from each channel, as in Fig. Figure 9B shows that channel 1 is measured 4 times, channel 2 4 times, and so on. Averaging N measurements per channel for Gaussian noise results in a √N improvement in the SNR for each channel (which can also be called √N noise reduction). As shown in Fig. As shown in Figure 9B, however, the measurements are still taken sequentially (i.e., progressing channel by channel), so the acquisition rate is slower than techniques that do not use averaging. In particular, it shows Fig. 9B the acquisition of 4 channels 912 in 16 cycles 914 compared to the acquisition of 4 channels in 4 cycles, which in Fig. Figure 9A shows that such a long acquisition period is detrimental to the touch panel parsing speed. The description of measuring channels as "sequential" or in a particular order is not intended to imply that the channels are adjacent (or that acquisition lines are adjacent), nor is it intended to imply that the disclosure requires that acquired signals be taken in a particular order or that channel measurements be taken in any particular order.

[0034] Some embodiments of the disclosure generally relate to the simultaneous acquisition of detected signals on multiple sensor channels of a capacitive sensor and the application of spread coding to the simultaneously acquired signals. The spread-coded signals can be decoded and processed by a touch processor. Spread coding of the acquired signals improves the noise tolerance of a touch interface. Accordingly, one or more embodiments of the disclosure relate to a noise-tolerant touch acquisition system.

[0035] One advantage of simultaneously acquiring sensor signals and using spread coding is that it decouples the trade-off between parsing speed and SNR to varying degrees. In other words, given a single-channel acquisition system with an SNR of 1, a system implementing N-channel acquisition according to embodiments of the disclosure exhibits a signal-to-noise ratio of SNR 1. N = sqrt(N) * SNR1, which can also be characterized as sqrt(N) noise reduction. Thus, the signal-to-noise ratio of an embodiment of an 8-channel system implementing embodiments of this disclosure can have an SNR of sqrt(8)*SNR1 compared to a single-channel acquisition system, but without a corresponding drop in parsing speed, which can also be described as a decrease in the update rate.

[0036] Furthermore, a capacitive acquisition system incorporating the acquisition and / or measurement techniques of this disclosure can achieve the same SNR performance as a single-channel acquisition system, but with a greater number of channels. N For example, a 16x16 channel touch panel incorporating capacitive sensing according to embodiments of the disclosure can achieve 16 times the update rate of a 16x16 channel touch panel incorporating single-channel acquisition techniques. In other words, a 16x16 channel touch panel according to embodiments of the disclosure has a 160 Hz update rate compared to a 10 Hz update rate for the 16x16 channel touch panel using conventional single-channel acquisition techniques.

[0037] In various embodiments, the selected spreading codes are orthogonal to allow for better differentiation between the contributing detected signals and the accumulated signals. In other words, if there are three spreading codes, each spreading code is orthogonal to the other two. Generally, the number of spreading codes used will correspond to the number of channels of a touch sensor that are being acquired simultaneously.

[0038] Fig. Figure 1 shows the operation of a capacitive sensor incorporating acquisition and measurement techniques according to one or more embodiments of the disclosure. In this example, detected signals (e.g., a charge) on channels 102 (i.e., Ch. 1 to Ch. 8) are acquired simultaneously over 8 acquisition cycles. In this example, there are no capacitance changes. The Tx value 106 indicates the base channel capacitance (e.g., no touches on a touch panel). Here, the charge on each channel indicates the magnitude of a drive signal applied to the drive lines.

[0039] Each bit of orthogonal spreading codes 104 is applied to channels 102 during each acquisition cycle. For example, code "0000 0000" is applied to the captured signal from Ch 1, code "0101 0101" is applied to Ch 2, and so on, with each subsequent bit (from left to right) being applied during each acquisition cycle. Therefore, if the code 104 of "0000 0000" is folded with the Tx value 106 of Ch 1 (a "1") over eight acquisition cycles, the coded Tx-coded value 110 corresponding to Ch 1 is "-1 -1 -1 -1 -1 -1", if the code "0101 0101" is folded with the Tx value 106 of Ch 2 (a "1"), the coded Tx value 110 corresponding to Ch 2 is "-1 1 -1 1 -1 1 -1 1", and so on.

[0040] Each bit in a coded Tx value 110 of a channel represents a positive or negative contribution to the value accumulated at an acquisition switching logic. Thus, the contribution of the first bit 110a of the Tx value 110 for each channel can be considered as~ "-8" or (-1)+ (-1)+ (-1)+ (-1)+ (-1)+ (-1)+ (-1)+ (-1)=-8 can be accumulated, and the contribution of the next bit 110b of the Tx word 110 for each channel can be accumulated as "0" or (-1)+ (1)+ (-1)+ (1)+ (-1)+ (1)+ (-1)+ (1)=0, and so on. The coded accumulated Tx value 108, which is ultimately transmitted to the digital control, is "-8 0 0 0 0 0 0 0".

[0041] The coded accumulated Tx value 108 can be decoded in response to the orthogonal spreading codes 104 to arrive at the coded intermediate value 114 for each acquisition channel. Thus, the coded intermediate data 114 for Ch. 1 is "8 0 0 0 0 0 0 0", the coded intermediate value 114 for Ch. 2 is "8 0 0 0 0 0 0 0", and so on. A received value (Rx value) 116 can be decoded in response to the coded intermediate value 114 for each channel. In one or more embodiments, the Rx value 116 is determined by summing each entry of the coded intermediate value 114; for example, the Rx value 116 for Ch. 1 is 8, the Rx value 116 for Ch. 2 is 8, and so on. Due to a predefined convention implemented in this example, "8" corresponds to a logical "1" and "-8" corresponds to a logical "0". Thus, the Rx value 116 in this example corresponds to "1111 1111", which is the same as the Tx value 106, or, using a touch example, no touch.An average professional will understand that other conventions can be implemented.

[0042] Fig. Figure 2 shows a system diagram of an embodiment of a capacitive sensing system 200 according to one or more embodiments of the disclosure. The encoder 220 can be operationally coupled to the sensing channels 212 of the N-channel sensor 210 and can be configured to encode simultaneously acquired signals on the 1 to N sensing channels 212 (e.g., by modulating the signals). In one or more embodiments, the encoder 220 can comprise N encoders, and each such encoder can be configured to encode an assigned channel of the N-channel sensor 210 in response to a spreading code. In one or more embodiments, the encoder 220 can be a digital logic circuit configured to implement the convolution of spreading codes with the acquired signals. In one or more embodiments, each spreading code can be implemented as a digital circuit.In another embodiment, a generic digital circuit can be configured to implement the convolution in response to one or more spreading codes.

[0043] The accumulator 230 can be operationally coupled to the encoder 220 and configured to receive captured coded 1 to N signals. In one or more embodiments, the accumulator 230 can include a charge-to-voltage converter (not shown) configured to accumulate charge and output a voltage in response to the charge. In one or more embodiments, the accumulator 230 can include charge-and-transfer switching logic that accumulates charge on integrating capacitor(s) and outputs discrete voltages faster or slower in response to a channel capacitance and / or a change in the channel capacitance.

[0044] Decoder 240 can be operationally coupled to accumulator 230. Decoder 240 can be configured to receive spread-coded analog or digital signals from accumulator 230 (for example, coupled to an output of a charge-to-voltage converter, coupled to an output of an analog-to-digital converter, etc.), to decode the received signals in response to one or more spreading codes, and to output decoded signals. Decoder 240 can be configured to decode the accumulated coded signals and generate coded intermediate values ​​that indicate each channel's contribution to the accumulated coded values. Each such coded intermediate value for each channel can be generated over successive acquisition cycles.

[0045] In one or more embodiments, the decoder 240 can be hardware or digital switching logic coupled to the digital controller 250. In another embodiment, the decoder 240 can be implemented in software, for example, in the software of the digital controller 250.

[0046] In one or more embodiments, the encoder 220, the accumulator 230, and the decoder 240 can form an acquisition switching logic for the capacitive sensing system 200, for example, a front-end acquisition switching logic. In another embodiment, the encoder 220 and the accumulator 230 can form an acquisition switching logic for the capacitive sensing system 200, and the decoder 240 can be implemented on the digital controller 250, for example, in software.

[0047] The digital controller 250 can be operationally coupled to the decoder 240 and can be configured to determine a channel capacitance measurement for one or more channels in response to coded intermediate values. In one or more embodiments, the digital controller 250 can include one or more touch processors (not shown) configured to determine touch information in response to channel capacitance measurements. For example, the position (e.g., xy position, pixel position, etc.) of a touch on a touch-sensitive surface (not shown) that is operationally coupled to the N-channel sensor 210.In one or more embodiments, the digital controller 250 can be configured to provide touch information for an interface (not shown) for a data bus (not shown), for example a universal asynchronous receiver-transmitter (UART), a universal synchronous / asynchronous receiver-transmitter (USART), or an interintegrated circuit (I. 2 C) In one or more embodiments, the data bus can be a peripheral data bus that is operationally coupled to a microcontroller, and one or more of the accumulator 230, encoder 220 and digital control 250 can be part of an integrated circuit package together with the microcontroller.

[0048] Fig. Figure 3 shows an exemplary measurement that can be performed on a capacitive sensor system 200 according to one or more embodiments of the disclosure. In this example, charge is accumulated from channel 4 in response to a channel capacitance change. A channel capacitance is represented here by a "3". The encoder 220 applies the spreading code 302 of "0110 0110" to channel 4, and the result is a spread coded value 304 of "-3, 3, 3, -3, -3, -3, 3, 3, -3". The spread coded value 304 is accumulated with the spread coded values ​​assigned to the other channels, and the spread coded accumulated Tx value 306 is "-4, 4, 0, 0, -4, 4, 0, -8". Decoder 240 decodes the Tx value 306 in response to the spreading codes used to encode each channel and constructs spread-coded intermediate values ​​that indicate each channel's contribution to the accumulated values. The spread-coded intermediate value 308 for Ch.4 is “4, 4, 0, 0, 4, 4, 0, 8”.

[0049] The digital controller 250 decodes each coded intermediate value it receives by summing the values ​​of each bit of the coded intermediate value to determine a received value for each detected channel. Here, the channel capacity measurement 310 for Ch. 4, determined in response to the coded intermediate value, is "24".

[0050] In the case of a touch application, a touch processor (not shown) can be configured to compare the channel capacity measurements for each channel with one or more threshold values ​​and, in response to the comparison, determine touch information (e.g., whether a touch occurred, where it occurred (e.g., x and y coordinates), when it occurred (e.g., a counter), and other touch information).

[0051] Fig. Figure 4 shows an example of the noise tolerance of a capacitive sensor system 200 according to one or more embodiments of the disclosure. Here, the noise 402 is transmitted with the coded accumulated Tx values ​​404. The noise 402 can, for example, be the result of unwanted capacitive coupling with another subsystem, power supplies, humidity, etc., which affect the measurement of the channel capacitance by a capacitive sensor system. As in Fig. As shown in Figure 4, due to the noise 402, the coded accumulated Tx values ​​404 do not exactly match what would be transmitted in a 100% noise-insensitive capacitive acquisition system. Nevertheless, the measurement 406 for Ch. 4, which is determined by the digital controller 250 in response to the intermediate values ​​408, includes only a small error (24 - 23.5 = 0.5) due to the noise 402.

[0052] Fig. Figure 5A shows a flowchart of an acquisition process with coded sensing channels of a capacitive sensing system according to embodiments of the disclosure. In process 502, drive signals are activated on the drive channels of a capacitive sensor. In one or more embodiments, the drive signals can indicate a sensing operation being performed on the capacitive sensing system. The drive signals can be activated for multiple acquisition cycles, which constitute a concurrent acquisition period. In process 504, sensed signals on N sensing channels of the capacitive sensor are spread-coded in response to spreading codes. In one or more embodiments, a different N-bit spreading code is applied to each sensing channel, and each spreading code is orthogonal to the other spreading codes. In one or more embodiments, a sensed signal is spread over one bit of the applicable spreading code per acquisition cycle.In process 506, N spread coded bits are accumulated, each corresponding to a different channel. In process 508, the current spread coded accumulated bit is transmitted, for example, to the digital controller 250. In each acquisition cycle, the acquired signals are spread across an additional spread code bit until, after a concurrent acquisition period sufficient for multiple acquisition cycles, the acquired signals have been spread across the entire spread code, accumulated, and transmitted.

[0053] Fig. Figure 5B shows a flowchart of a process for decoding spread-coded acquired signals and using the decoded signal to determine a channel capacity measurement according to embodiments of the disclosure. In step 512, the spread-coded accumulated value is received. In step 514, the spread-coded accumulated value is decoded in response to the spreading codes. In step 516, the coded intermediate value is determined for each channel in response to the decoding. In one or more embodiments, a decoding operation is applied which is the logical counterpart of the coding sequences applied to each channel to encode the transmitted value in order to arrive at each intermediate value. In step 518, the intermediate value is further decoded for at least one channel. In one or more embodiments, each bit of the coded intermediate value is summed with the other bits.In process 520, a channel capacity measurement is determined in response to the decoding.

[0054] Noise can also be introduced into the drive or acquisition lines of a capacitive sensing system. Accordingly, in some embodiments of the disclosure, the drive signals are encoded using orthogonal spreading codes and modulated over a number of frequencies, and then drive lines are driven using the encoded and frequency-spread drive signals. A despiser and a decoder demodulate and decode the acquired signals before they are transmitted to a digital controller.

[0055] Fig. Figure 6 shows a capacitive sensor system that incorporates spread coding according to one or more embodiments of the disclosure. The capacitive sensing system 600 includes, on the control side, an encoder 610, a code spreader 620, and a surface with control channels 630. The encoder 610 can be configured to encode the control signals 602 in response to spread codes. For each acquisition cycle, the encoder 610 can be configured to encode a control signal for a channel with an additional bit of an applicable spread code. The code spreader 620 can be operationally coupled to the encoder 610 and configured to modulate each spread-coded control signal in response to a transmit frequency (e.g., Fx, ½Fx, ¼Fx, etc.) assigned to the channel.For example, the code spreader 620 can spread "1010" as "1010" in response to an Fx transmit frequency, "1010" as "1111 0000 1111 0000" in response to a 1 / 2 Fx transmit frequency, and "1010" as "1111 1111 0000 0000 1111 1111 0000 0000" in response to a 1 / 4 Fx transmit frequency. The code spreader 620 can be operationally coupled to the control channels of a surface with control channels 630 and configured so that the coded and frequency-spread control signals can be activated on the control channels.

[0056] The acquisition side of the capacitive sensing system 600 includes a sensor with Y sensing channels 640, an acquisition switching logic 650, a spreader 660, a decoder 670, and a digital controller 680. In one or more embodiments, the decoder 670 can be part of the digital controller 680, for example, a process executed in firmware or switching logic. The acquisition switching logic 650 can be operationally coupled to the sensing channels 640 and configured to simultaneously acquire detected signals from the sensing channels 640, including signals indicating channel capacity and changes in channel capacity. The spreader 660 can be operationally coupled and configured with the acquisition switching logic 650 to frequency demodulate the coded and spread-based acquired signals that have accumulated at the acquisition switching logic 650.The spreader 660 can be operationally coupled with the decoder 670, and the decoder 670 can be configured to decode the encoded accumulated signals in response to the orthogonal spreading codes used to encode the control lines. The result of the decoding can be an encoded intermediate value or data for each channel. The decoder 670 can be configured to further decode the intermediate value and determine a value that specifies the channel capacity for each of the sensing channels 640. The digital controller 680 can be configured to further process the channel capacity values ​​and, for example, determine touch information in response to the channel capacity values.

[0057] While the acquisition switching logic 650, the spreader 660, and the decoder 670 are described as independent units, in one or more embodiments the spreader 660, the decoder 670, and an accumulator (not shown) together form the acquisition switching logic 650. One or more embodiments can implement analog-to-digital conversion (ADC conversion) in various stages, for example, after charge accumulation, after spreading, or after decoding. Furthermore, in one or more embodiments, one or more of the spreader 660 and the decoder 670 can be implemented in the digital controller 680, for example, in software executed by a microprocessor.

[0058] In one or more embodiments, one or more of the spreader 660, the decoder 670, and the digital controller 680 can be implemented as part of a microcontroller with memory, a microprocessor, input / output ports, and optionally one or more peripheral devices. In another embodiment, one or more of the spreader 660, the decoder 670, and the digital controller 680 can be implemented as hardware switching logic or digital switching logic of a peripheral device, or, if a peripheral device is implemented on a microprocessor, as software.

[0059] Fig. Figure 7A shows a flowchart of a coded drive process 700 for coding sensing channels of a capacitive sensing system according to embodiments of the disclosure. In process 702, drive signals are spread-coded in response to spreading codes. In one or more embodiments, each drive signal is configured to be activated on a different drive channel of a capacitive sensor. A different N-bit spreading code is applied to each drive signal, and each spreading code is orthogonal to the other spreading codes. In one or more embodiments, a drive signal is spread over one bit of an applicable spreading code per sensing cycle. Information about the sensing cycle or cycles over which drive signals are coded and spread can be provided. In process 704, drive signals are frequency-spread in response to transmit frequencies assigned to the drive channels.In process 706, the coded and frequency-spread control signals are activated on the control channels of the capacitive sensor. In process 708, signals detected by the detection channels of the capacitive sensor are accumulated.

[0060] Fig. Figure 7B shows a flowchart of a spread acquisition process 710 for decoding accumulated acquired signals generated in response to frequency spreading and coded drive signals, and for using the result to determine a channel capacity measurement according to embodiments of the disclosure. In process 712, the frequency-spread-coded accumulated acquired signals are received. In particular, due to the frequency spreading N * f Verhältnis take to receive all accumulated detected signals, where f VerhättnisThe ratio of the most spread signal to a unit signal (i.e., 1, 2, 4, etc.) is defined. In process 714, the accumulated captured signals are demodulated (which may also be referred to as "unspreading" in this disclosure). In one or more embodiments, the accumulated captured signals may be converted into digital signals before demodulation. In process 716, a first decoding of the demodulated captured signals is performed in response to the spreading codes used to encode the drive signals. In one or more embodiments, coded intermediate values ​​are generated in response to a decoding operation applied to the accumulated captured signals, the decoding operation being logically opposite to the encoding sequences applied to each channel to encode the drive signals.In step 718, coded intermediate signals are determined in response to the first decoding. In step 720, a further decoding of the intermediate data is performed for at least one channel. In one or more embodiments, the other decoding may include summing the bits of the intermediate data. In step 722, a channel capacity measurement is determined for the at least one channel in response to the second decoding.

[0061] Embodiments of capacitive sensing systems described in this disclosure may be integrated into touch interfaces configured to perform touch processing and force processing. Fig. Figure 8 shows a force sensing operation in a noise-tolerant touch interface according to an embodiment of the disclosure. Pressure measurements 802 (i.e., force) are determined by further processing the capacitance measurements based on the acquired signals.

[0062] A person skilled in the art will recognize that embodiments of the disclosure can be applied to more than just converting the change in capacitance into voltage; for example, the same principles apply to using the change in charge to determine the frequency and the change in charge to determine the current. Thus, touch embodiments of the present disclosure are not limited to touch controls that measure voltage to detect contact, but also apply to touch controls that measure frequency and current (or changes in frequency and / or current).

[0063] An average person skilled in the art will recognize that embodiments of the disclosure, in addition to overcoming shortcomings of some conventional acquisition techniques, offer many advantages and significant benefits. For example, compared to conventional acquisition techniques, embodiments can provide improvements in parsing speed and therefore the ability to parse larger panels within the same time constraints as conventional acquisition techniques; improvements in the signal-to-noise ratio and therefore operation at the same parsing speed achieved with conventional single-channel acquisition, but with higher noise immunity; and energy-saving improvements, since faster operation allows the use of a device for shorter periods and less energy consumption over time.

[0064] Many of the functional descriptions in this specification can be illustrated, described, or referred to as modules, threads, or other segregations of programming code, including firmware, to more clearly emphasize their implementation independence. Modules can be implemented in hardware, at least partially, in one form or another. For example, a module can be implemented as a hardware circuit comprising user-defined VLSI circuits or gate arrays, commercially available semiconductors such as logic chips, transistors, or other discrete components. A module can also be implemented in programmable hardware devices such as field-programmable gate arrays, programmable array logic, programmable logic devices, or the like.

[0065] Modules can also be implemented in memory, or a combination thereof, for execution by different types of processors, using software or firmware stored on a physical storage device (e.g., a computer-readable storage medium).

[0066] An identified module of executable code can, for example, comprise one or more physical or logical blocks of computer instructions, which may be organized as a thread, object, procedure, or function. However, the executable files of an identified module do not need to be physically located together; they can comprise different instructions stored in various locations which, when logically combined, constitute the module and achieve its stated purpose.

[0067] In fact, a module of executable code can be a single instruction or many instructions and can even be distributed across several different code segments, between different programs, and across multiple storage devices. Similarly, operational data can be identified and illustrated herein within modules and can be embodied in any suitable form and organized within any suitable type of data structure. The operational data can be collected as a single data record or distributed across different locations, including different storage devices, and can exist, at least in part, merely as electronic signals in a system or network. When a module or sections of a module are implemented in software, the software sections are stored on one or more physical devices referred to herein as computer-readable media.

[0068] In some embodiments, the software sections are stored in a non-volatile state, so that the software sections, or representations thereof, remain in the same physical location for a period of time. Additionally, in some embodiments, the software sections are stored in one or more non-volatile storage devices that include hardware elements capable of storing non-volatile states and / or signals representative of the software sections, although other sections of the non-volatile storage devices may be capable of modifying and / or transmitting the signals. Examples of non-volatile storage devices include flash memory and random-access memory (RAM). Another example of a non-volatile storage device includes read-only memory (ROM) capable of storing signals and / or states representative of the software sections for a period of time.The ability to store signals and / or states is not affected by further functionality for transmitting signals that correspond to or represent the stored signals and / or states. For example, a processor can access the ROM to obtain signals representative of the stored signals and / or states in order to execute the appropriate software instructions.

[0069] Additional, non-restrictive embodiments of the disclosure include: Embodiment 1: Capacitive sensing system comprising: a sensor switching logic comprising sensing lines; an acquisition switching logic operationally coupled to the sensing lines, wherein the acquisition switching logic is configured to receive sensing signals indicating one or more capacitances at the sensor switching logic and to provide accumulated shared sensing signals in response to the sensing signals; and a digital controller operationally coupled to the acquisition switching logic and configured to determine a channel capacitance measurement in response to the accumulated shared sensing signals. Embodiment 2: System according to embodiment 1, wherein the acquisition switching logic is configured to: receive the acquired signals at the acquisition lines; split the acquired signals; and accumulate the split acquired signals. Embodiment 3: System according to one of the preceding embodiments, wherein the acquisition switching logic is configured to split the acquired signals by spreading the acquired signals in response to one or more spreading codes. Embodiment 4: System according to one of the preceding embodiments, wherein at least one spreading code of the one or more spreading codes is a binary code comprising two or more bits. Embodiment 5: System according to one of the preceding embodiments, wherein the acquisition switching logic is configured to receive the acquired signals during an acquisition period, the acquisition period comprising two or more acquisition cycles. Embodiment 6: System according to one of the preceding embodiments, wherein the acquisition lines comprise a first acquisition line and the acquisition switching logic is configured to: receive first acquired signals of the acquired signals at the first acquisition line during an acquisition period; spread the first acquired signals in response to a first spreading code during a first acquisition cycle of the acquisition period; and spread the first acquired signals in response to the first spreading code during a second acquisition cycle of the acquisition period. Embodiment 7: System according to one of the preceding embodiments, wherein the first spreading code comprises at least a first bit and a second bit and the acquisition switching logic is configured to: fold a first acquired signal of the first acquired signals with the first bit of the first spreading code; and fold a second acquired signal of the first acquired signals with the second bit of the first spreading code. Embodiment 8: System according to one of the preceding embodiments, wherein the acquisition switching logic is configured to: fold the first acquired signal of the first acquired signals with the first bit of the first spreading code during the first acquisition period; and fold the second acquired signal of the first acquired signals with the second bit of the first spreading code during a second acquisition period. Embodiment 9: System according to one of the preceding embodiments, wherein the acquisition lines include a second acquisition line and the acquisition switching logic is configured to: receive second acquired signals of the acquired signals on the first acquisition line during the acquisition period; spread the second acquired signals in response to a second spreading code during the first acquisition cycle of the acquisition period; and spread the second acquired signals in response to the second spreading code during the second acquisition cycle of the acquisition period. Embodiment 10: System according to one of the preceding embodiments, wherein the second spreading code comprises at least a first bit and a second bit and the acquisition switching logic is configured to: fold a first acquired signal of the second acquired signals with the first bit of the second spreading code; and fold a second acquired signal of the second acquired signals with the second bit of the second spreading code. Embodiment 11: System according to one of the preceding embodiments, wherein the second spreading code comprises at least a first bit and a second bit, wherein the acquisition switching logic is configured to: fold the first acquired signal of the second acquired signals with the first bit of the second spreading code during the first acquisition period; and fold the second acquired signal of the second acquired signals with the second bit of the second spreading code during the second acquisition period. Embodiment 12: System according to one of the preceding embodiments, wherein the acquisition lines comprise a second acquisition line and a second acquisition line, and the acquisition switching logic is configured to: receive a first acquired signal on the first acquisition line and a second acquired signal on the second acquisition line; spread the first acquired signal in response to a first spreading code of one or more spreading codes; spread the second acquired signal in response to a second spreading code of one or more spreading codes; and accumulate the spread first acquired signal and the spread second acquired signal. Embodiment 13: System according to one of the preceding embodiments, wherein the digital control is configured to differentiate the accumulated split detected signals in response to one or more spreading codes. Embodiment 14: System according to one of the preceding embodiments, wherein the digital control is configured to determine touch information in response to the channel capacity measurement. Embodiment 15: System according to one of the preceding embodiments, wherein the digital control is configured to provide the one or more spreading codes. Embodiment 16: System according to one of the preceding embodiments, wherein the one or more spreading codes comprise a digital logic circuit configured to receive captured signals and acquisition cycle information and to provide a spread captured signal. Embodiment 17: Method for acquiring detected signals from a capacitive sensor, comprising: receiving one or more detected signals on one or more sensor channels associated with a capacitive sensor; splitting the one or more detected signals; and accumulating one or more split detected signals. Embodiment 18: Method according to one of the preceding embodiments, wherein the splitting of the one or more detected signals comprises spreading the detected signals in response to one or more spreading codes. Embodiment 19: Method according to one of the preceding embodiments, wherein at least one spreading code of the one or more spreading codes is a binary code comprising two or more bits. Embodiment 20: Method according to one of the preceding embodiments, further comprising receiving the acquired signals during an acquisition period, wherein the acquisition period comprises two or more acquisition cycles. Embodiment 21: Method according to one of the preceding embodiments, further comprising: receiving first acquired signals of the acquired signals at a first acquisition line of the acquisition lines during an acquisition period; spreading the first acquired signals in response to a first spreading code during a first acquisition cycle of the acquisition period; and spreading the first acquired signals in response to the first spreading code during a second acquisition cycle of the acquisition period. Embodiment 22: Method according to one of the preceding embodiments, further comprising: folding a first detected signal of the first detected signals with a first bit of the first spreading code; and folding a second detected signal of the first detected signals with a second bit of the first spreading code. Embodiment 23: Method according to one of the preceding embodiments, further comprising: receiving second acquired signals of the acquired signals at a second acquisition line of the acquisition lines during the acquisition period; spreading the second acquired signals in response to a second spreading code during the first acquisition cycle of the acquisition period; and spreading the second acquired signals in response to the second spreading code during the second acquisition cycle of the acquisition period. Embodiment 24: Method according to one of the preceding embodiments, further comprising: folding a first detected signal of the second detected signals with a first bit of the second spreading code; and folding a second detected signal of the second detected signals with a second bit of the second spreading code. Embodiment 25: Method according to one of the preceding embodiments, further comprising: receiving a first detected signal at a first detection line of the detection lines and a second detected signal at a second detection line of the detection lines; spreading the first detected signal in response to a first spreading code of one or more spreading codes; spreading the second detected signal in response to a second spreading code of one or more spreading codes; and accumulating the spread first detected signal and the spread second detected signal. Embodiment 26: Method according to one of the preceding embodiments, further comprising differentiating the accumulated split detected signals in response to one or more spreading codes. Embodiment 27: Method according to one of the preceding embodiments, further comprising determining at least one channel capacity measurement in response to the one or more shared detected signals. Embodiment 28: Method according to one of the preceding embodiments, further comprising determining touch information in response to the at least one channel capacity measurement. Embodiment 29: Method according to any of the preceding embodiments, further comprising: differentiating the accumulated split detected signals in response to one or more spreading codes; integrating one or more individual split detected signals; and determining one or more capacitive channel measurements in response to the integrated detected signals. Embodiment 30: Method according to one of the preceding embodiments, wherein each spreading code is assigned to one of the one or more sensor lines. Embodiment 31: Digital control for capacitive sensing, wherein the control comprises: a decoder configured to: differentiate accumulated sensed signals in response to one or more spreading codes; and integrate differentiated split sensed signals, and a processor configured to determine one or more capacitive channel measurements in response to the integrated sensed signals. Embodiment 32: Digital control according to one of the preceding embodiments, wherein the decoder is configured to: determine first differentiated split detected signals in response to a first spreading code of one or more spreading codes and the accumulated detected signals. Embodiment 33: Control according to one of the preceding embodiments, wherein the first differentiated split detected signal comprises at least two intermediate values ​​and the decoder is configured to integrate the first differentiated split detected signal by adding the at least two intermediate values. Embodiment 34: Control according to one of the preceding embodiments, wherein the decoder is configured to: determine second differentiated split detected signals in response to a second spreading code of one or more spreading codes and the accumulated detected signals. Embodiment 35: Control according to one of the preceding embodiments, wherein the second differentiated split detected signal comprises at least two intermediate values ​​and the decoder is configured to integrate the second differentiated split detected signal by adding the at least two intermediate values. Embodiment 36: Control according to one of the preceding embodiments, wherein the processor is configured to determine touch information in response to one or more capacitive channel measurements. Embodiment 37: Control according to one of the preceding embodiments, wherein the processor is configured to provide one or more spreading codes of an acquisition switching logic. Embodiment 38: Method for controlling a capacitive sensing system, wherein the control comprises: differentiating accumulated sensing signals in response to one or more spreading codes; integrating differentiated split sensing signals and determining one or more capacitive channel measurements in response to the integrated sensing signals. Embodiment 39: Method according to one of the preceding embodiments, further comprising determining first differentiated split detected signals of the differentiated split detected signals in response to a first spreading code of one or more spreading codes and the accumulated detected signals. Embodiment 40: Method according to one of the preceding embodiments, wherein the first differentiated split detected signal comprises at least two intermediate values ​​and the method further comprises integrating the first differentiated split detected signal by adding the at least two intermediate values. Embodiment 41: Method according to one of the preceding embodiments, further comprising determining the second differentiated split detected signals in response to a second spreading code of one or more spreading codes and the accumulated detected signals. Embodiment 42: Method according to one of the preceding embodiments, wherein the second differentiated split detected signal comprises at least two intermediate values ​​and the method further comprises integrating the second differentiated split detected signal by adding the at least two intermediate values. Embodiment 43: Method according to one of the preceding embodiments, further comprising determining touch information in response to one or more capacitive channel measurements. Embodiment 44: Method according to one of the preceding embodiments, further comprising providing one or more spreading codes. Embodiment 45: Capacitive sensing system comprising: a sensor switching logic comprising sensing lines and drive lines; an encoder configured to provide coded drive signals in response to one or more spreading codes; a frequency spreader configured to provide modulated drive signals in response to one or more transmit frequencies and one or more coded drive signals; an acquisition switching logic configured to provide accumulated signals in response to one or more acquired signals; a frequency demodulator configured to provide demodulated signals in response to one or more accumulated signals; a decoder configured to provide differentiated signals in response to one or more demodulated signals;and digital logic configured to provide channel capacity measurements in response to one or more differentiated signals. Embodiment 46: System according to one of the preceding embodiments, wherein at least one spreading code of the one or more spreading codes is a binary code comprising two or more bits. Embodiment 47: System according to one of the preceding embodiments, wherein the encoder is configured to spread control signals in response to one or more spreading codes. Embodiment 48: System according to one of the preceding embodiments, wherein the encoder is configured to spread control signals in response to a first spreading code and to spread control signals in response to a second spreading code. Embodiment 49: System according to one of the preceding embodiments, wherein the frequency spreader is configured to modulate first coded drive signals in response to a first transmit frequency. Embodiment 50: System according to one of the preceding embodiments, wherein the frequency spreader is configured to modulate second coded control signals in response to a second transmit frequency. Embodiment 51: System according to one of the preceding embodiments, wherein the encoder is configured to provide the coded drive signals during an acquisition period, and the frequency spreader is configured to provide the modulated drive signals during the acquisition period, wherein the acquisition period comprises one or more acquisition cycles. Embodiment 52: System according to one of the preceding embodiments, wherein the encoder is configured to provide first coded drive signals during a first acquisition cycle of the acquisition period, and the frequency spreader is configured to provide first modulated drive signals during the first acquisition cycle. Embodiment 53: System according to one of the preceding embodiments, wherein the encoder is configured to provide second coded drive signals during a second acquisition cycle of the acquisition period, and the frequency spreader is configured to provide the second modulated drive signals during the second acquisition cycle, the second acquisition cycle following the first acquisition cycle. Embodiment 54: System according to one of the preceding embodiments, wherein the encoder is configured to provide first coded control signals in response to a first spreading code of one or more spreading codes and to provide second coded control signals in response to a second spreading code of one or more spreading codes. Embodiment 55: System according to one of the preceding embodiments, wherein the encoder is configured to provide the first coded control signals and the second coded control signals during the same acquisition period. Embodiment 56: System according to one of the preceding embodiments, wherein the frequency spreader is configured to provide first modulated control signals in response to a first frequency transmission of one or more frequency transmissions and to provide second modulated control signals in response to a second frequency transmission of one or more frequency transmissions. Embodiment 57: System according to one of the preceding embodiments, wherein the frequency spreader is configured to provide the first modulated drive signals and the second modulated drive signals during the same acquisition period. Embodiment 58: System according to one of the preceding embodiments, wherein the sensor switching logic is configured to receive the modulated control signals on control lines. Embodiment 59: System according to one of the preceding embodiments, wherein the sensor switching logic is configured to receive first modulated control signals on a first control line and to receive second modulated control signals on a second control line, wherein the first modulated control signals have a first frequency and the second modulated control signals have a second frequency. Embodiment 60: System according to one of the preceding embodiments, wherein the sensor switching logic is configured to provide the detected signals on one or more detection lines. Embodiment 61: System according to one of the preceding embodiments, wherein the detected signals indicate one or more capacitances at the sensor switching logic. Embodiment 62: System according to one of the preceding embodiments, wherein the acquisition switching logic is configured to accumulate the detected signals, the detected signals being received at the detection lines. Embodiment 63: System according to one of the preceding embodiments, wherein the frequency spreader is configured to demodulate accumulated signals in response to the one or more transmit frequencies. Embodiment 64: System according to one of the preceding embodiments, wherein the decoder is configured to distinguish the demodulated signals in response to one or more spreading codes. Embodiment 65: System according to one of the preceding embodiments, wherein a first differentiated signal of one or more differentiated signals comprises at least two intermediate values ​​and the digital logic is configured to integrate the first differentiated signal by summing the at least two differentiated values. Embodiment 66: System according to one of the preceding embodiments, wherein the digital logic is configured to determine touch information in response to the channel capacity measurements. Embodiment 67: System according to one of the preceding embodiments, wherein the digital logic is configured to provide one or more spreading codes. Embodiment 68: System according to one of the preceding embodiments, wherein the one or more spreading codes comprise a digital logic circuit configured to receive drive signals and acquisition cycle information and to provide coded drive signals. Embodiment 69: A method for detecting the channel capacity of a sensor switching logic, the method comprising: encoding control signals in response to one or more spreading codes; modulating encoded control signals in response to one or more transmit frequencies and one or more encoded control signals; providing modulated encoded control signals to control lines of the sensor switching logic; acquiring detected signals at detection lines of the sensor switching logic; demodulating the detected signals in response to the one or more transmit frequencies; decoding demodulated detected signals in response to the one or more spreading codes; and measuring the channel capacity of the sensor switching logic in response to one or more demodulated detected signals. Embodiment 70: Method according to one of the preceding embodiments, further comprising that at least one spreading code of the one or more spreading codes is a binary code comprising two or more bits. Embodiment 71: Method according to one of the preceding embodiments, further comprising encoding control signals in response to a first spreading code and encoding control signals in response to a second spreading code. Embodiment 72: Method according to one of the preceding embodiments, further comprising modulating first coded control signals in response to a first transmission frequency. Embodiment 73: Method according to one of the preceding embodiments, further comprising modulating second coded control signals in response to a second transmission frequency. Embodiment 74: Method according to one of the preceding embodiments, further comprising providing the coded control signals during an acquisition period and providing the modulated control signals during the acquisition period, wherein the acquisition period comprises one or more acquisition cycles. Embodiment 75: Method according to one of the preceding embodiments, further comprising providing first coded control signals during a first acquisition cycle of the acquisition period and providing first modulated control signals during the first acquisition cycle. Embodiment 76: Method according to one of the preceding embodiments, further comprising providing second coded control signals during a second acquisition cycle of the acquisition period and providing the second modulated control signals during the second acquisition cycle, wherein the second acquisition cycle follows the first acquisition cycle. Embodiment 77: Method according to one of the preceding embodiments, further comprising providing first coded control signals of the coded control signals in response to a first spreading code of one or more spreading codes and providing second coded control signals of the coded control signals in response to a second spreading code of one or more spreading codes. Embodiment 78: Method according to one of the preceding embodiments, further comprising providing the first coded control signals and the second coded control signals during the same acquisition period. Embodiment 79: Method according to one of the preceding embodiments, further comprising providing first modulated control signals in response to a first frequency transmission of one or more frequency transmissions and providing second modulated control signals in response to a second frequency transmission of one or more frequency transmissions. Embodiment 80: Method according to one of the preceding embodiments, further comprising providing the first modulated control signals and the second modulated control signals during the same acquisition period. Embodiment 81: Method according to one of the preceding embodiments, further comprising receiving the modulated control signals at control lines. Embodiment 82: Method according to one of the preceding embodiments, further comprising receiving first modulated control signals on a first control line and receiving second modulated control signals on a second control line, wherein the first modulated control signals have a first frequency and the second modulated control signals have a second frequency. Embodiment 83: Method according to one of the preceding embodiments, further comprising providing the detected signals on one or more detection lines. Embodiment 84: Method according to one of the preceding embodiments, wherein the detected signals indicate one or more capacitances at the sensor switching logic. Embodiment 85: Method according to one of the preceding embodiments, further comprising accumulating the detected signals, wherein the detected signals are received at the detection lines. Embodiment 86: Method according to one of the preceding embodiments, further comprising demodulating accumulated signals in response to one or more transmission frequencies. Embodiment 87: Method according to one of the preceding embodiments, further comprising differentiating the demodulated signals in response to one or more spreading codes. Embodiment 88: Method according to one of the preceding embodiments, wherein a first differentiated signal of one or more differentiated signals comprises at least two intermediate values. Embodiment 89: Method according to one of the preceding embodiments, further comprising summing the at least two differentiated values. Embodiment 90: Method according to one of the preceding embodiments, further comprising determining touch information in response to the channel capacity measurements. Embodiment 91: Method according to one of the preceding embodiments, further comprising providing one or more spreading codes. Embodiment 92: Method according to one of the preceding embodiments, wherein the one or more spreading codes comprise a digital logic circuit configured to receive drive signals and acquisition cycle information and to provide coded drive signals. Embodiment 93: Digital control for capacitive sensing, wherein the control comprises a digital logic circuit configured to provide channel capacitance measurements in response to one or more differentiated signals. Embodiment 94: Digital control according to one of the preceding embodiments, further comprising an encoder configured to provide coded control signals in response to one or more spreading codes. Embodiment 95: Digital control according to one of the preceding embodiments, further comprising a frequency spreader configured to provide modulated control signals in response to one or more transmit frequencies and one or more coded control signals. Embodiment 96: Digital control according to one of the preceding embodiments, further comprising a frequency spreader configured to provide demodulated signals in response to one or more accumulated signals. Embodiment 97: Digital control according to one of the preceding embodiments, further comprising a decoder configured to provide differentiated signals in response to one or more demodulated signals. Embodiment 98: Control method of one of the foregoing embodiments, comprising providing channel capacity measurements in response to one or more differentiated signals. Embodiment 99: Capacitive sensing method according to one of the preceding embodiments, comprising: receiving one or more coded and frequency-spread control signals at one or more control lines of a capacitive sensor; and providing one or more detected signals in response to the one or more coded frequency-spread control signals.

[0070] While the present disclosure has been described herein in relation to certain illustrated embodiments, those skilled in the art will recognize and acknowledge that the present invention is not limited thereto. Rather, many additions, deletions, and modifications can be made to the illustrated and described embodiments without departing from the scope of protection of the invention, as claimed below together with their legal equivalents. In addition, features of one embodiment can be combined with features of another embodiment while still remaining within the scope of protection of the invention as envisaged by the inventor.

Claims

[1] Capacitive sensing system, comprising: a sensor switching logic that includes detection lines and sensor channels; an acquisition switching logic that is operationally coupled with the sensor channels, wherein the acquisition switching logic is configured to receive captured signals from the sensor channels indicating one or more capacities at the sensor switching logic, and to provide accumulated spread-coded captured signals in response to the capture signals; and where the acquisition switching logic is configured: to spread-code each of the received captured signals for each channel by applying mutually orthogonal spreading codes, where each bit of a spreading code is either a logical zero or a logical one; and to accumulate spread-coded values ​​for each channel in response to one or more orthogonal spreading codes used to encode each channel; and a digital control that is operationally coupled with the acquisition switching logic to determine a channel capacity measurement in response to the accumulated spread-coded values. [2] System according to claim 1, wherein at least one spreading code of the mutually orthogonal spreading codes is a code comprising two or more bits. [3] System according to claim 1, wherein the acquisition switching logic is configured to receive the acquired signals during an acquisition period, wherein the acquisition period comprises two or more acquisition cycles. [4] System according to claim 3, wherein the acquisition lines comprise a first acquisition line and the acquisition switching logic is configured to: Receiving the first captured signals of the captured signals at the first acquisition line during an acquisition period; and Spreading the first detected signals in response to an initial spreading code during the first acquisition cycle of the acquisition period; and Spreading the first detected signals in response to the first spreading code during a second acquisition cycle of the acquisition period. [5] System according to claim 4, wherein the first spreading code comprises at least a first bit and a second bit and the acquisition switching logic is configured to: Folding a first detected signal of the first detected signals with the first bit of the first spreading code; and Folding a second captured signal of the first captured signals with the second bit of the first spreading code. [6] System according to claim 5, wherein the acquisition switching logic is configured to: Folding the first captured signal of the first captured signals with the first bit of the first spreading code during a first acquisition period; and Folding the second captured signal of the first captured signals with the second bit of the first spreading code during a second acquisition period. [7] System according to claim 4, wherein the acquisition lines comprise a second acquisition line and the acquisition switching logic is configured to: Receiving the second captured signal of the captured signals at the first acquisition line during the acquisition period; Spreading of the second captured signals in response to a second spreading code during the first acquisition cycle of the acquisition period; and Spreading of the second detected signals in response to the second spreading code during the second acquisition cycle of the acquisition period. [8] System according to claim 7, wherein the second spreading code comprises at least a first bit and a second bit and the acquisition switching logic is configured to: Folding a second captured signal of the second captured signals with the first bit of the second spreading code; and Folding a second detected signal of the second detected signals with the second bit of the second spreading code. [9] System according to claim 7, wherein the second spreading code comprises at least a first bit and a second bit, wherein the acquisition switching logic is configured to: Folding the first captured signal of the second captured signals with the first bit of the second spreading code during the first acquisition period; and Folding the second captured signal of the second captured signals with the second bit of the second spreading code during the second acquisition period. [10] System according to claim 1, wherein the acquisition lines comprise a first acquisition line and a second acquisition line and the acquisition switching logic is configured to: Receiving a first detected signal on the first detection line and a second detected signal on the second detection line; Spreading of the first detected signal in response to an initial spreading code of one or more spreading codes; Spreading of the second detected signal in response to a second spreading code of one or more spreading codes; and Accumulating the spread first detected signal and the spread second detected signal. [11] System according to claim 1, wherein the digital control is configured to decode the accumulated spread-coded detected signals in response to the mutually orthogonal spreading codes. [12] System according to claim 1, wherein the digital control is configured to determine touch information in response to the channel capacity measurement. [13] System according to claim 1, wherein the digital control is configured to provide mutually orthogonal spreading codes. [14] System according to claim 1, further comprising digital logic circuits configured to receive spread-coded captured signals and acquisition cycle information and to provide a spread-coded captured signal. [15] System according to claim 1, wherein the mutually orthogonal spreading codes comprise: a first spreading code comprising a first group of bits; and a second spreading code comprising a second group of bits. [16] Method for acquiring detected signals from a capacitive sensor, comprising: Receiving one or more detected signals on one or more sensor channels assigned to a capacitive sensor; Spread coding of the one or more detected signals, wherein the spread coding of the one or more detected signals comprises applying spread codes to the detected signals in response to respective mutually orthogonal spread codes, each bit of a spread code being either a logical zero or a logical one; and Accumulating one or more spread-coded captured signals. [17] Method according to claim 16, wherein at least one spreading code of the mutually orthogonal spreading codes is a code comprising two or more bits. [18] Method according to claim 17, further comprising receiving the acquired signals during an acquisition period, wherein the acquisition period comprises two or more acquisition cycles. [19] The method of claim 18, further comprising: Receiving the first captured signals of the captured signals at a first acquisition line of the acquisition lines during an acquisition period; Spreading of the first detected signals in response to an initial spreading code during an initial detection cycle of the acquisition period; and Spreading the first detected signals in response to the first spreading code during a second detection cycle of the acquisition period. [20] The method of claim 19, further comprising: Folding a first detected signal of the first detected signals with a first bit of the first spreading code; and Folding a second captured signal of the first captured signals with a second bit of the first spreading code. [21] The method of claim 19, further comprising: Receiving a second set of captured signals at a second acquisition line during the acquisition period; Spreading of the second captured signals in response to a second spreading code during the first capture cycle of the acquisition period; and Spreading of the second captured signals in response to the second spreading code during the second capture cycle of the acquisition period. [22] The method of claim 21, further comprising: Folding a first detected signal of the second detected signals with a first bit of the second spreading code; and Folding a second detected signal of the second detected signals with a second bit of the second spreading code. [23] The method of claim 16, further comprising: Receiving a first detected signal at a first detection line of the detection lines and a second detected signal at a second detection line of the detection lines; Spreading of the first detected signal in response to an initial spreading code of mutually orthogonal spreading codes; Spreading of the second detected signal in response to a second spreading code of mutually orthogonal spreading codes; and Accumulating the spread first detected signal and the spread second detected signal. [24] Method according to claim 23, further comprising decoding the accumulated spread-coded detected signals in response to the mutually orthogonal spreading codes. [25] Method according to claim 16, further comprising determining at least one channel capacity measurement in response to the one or more spread-coded detected signals. [26] Method according to claim 25, further comprising determining touch information in response to at least one channel capacity measurement. [27] The method of claim 16, further comprising: Decoding the accumulated spread-coded captured signals in response to the mutually orthogonal spreading codes; Integrating one or more individual spread-coded captured signals; and Determining one or more capacitive channel measurements in response to the integrated one or more individual spread-coded captured signals. [28] Method according to claim 16, wherein each spreading code is assigned to one or more sensor lines. [29] The method of claim 16, wherein the spreading of the detected signals in response to the mutually orthogonal spreading codes comprises: the spreading of the detected signals in response to an initial spreading code comprising an initial group of bits; and the spreading of the detected signals in response to a second spreading code that includes a second group of bits. [30] Control for a capacitive sensing system, wherein the control system comprises: a decoder configured to: Decoding accumulated captured signals in response to one or more spreading codes, wherein the one or more spreading codes are mutually orthogonal, and wherein each bit of a spreading code of the one or more spreading codes is either a logical zero or a logical one; and Integrating decoded spread-coded captured signals, and a processor configured to determine one or more capacitive channel measurements in response to the integrated decoded spread-coded captured signals. [31] Control according to claim 30, wherein the one or more spreading codes comprise: a first spreading code comprising a first group of bits, and a second spreading code comprising a second group of bits, where the second group of bits is orthogonal to the first group of bits. [32] Control according to claim 30, wherein the decoder is configured to: Determining the first decoded spread-coded detected signals of the decoded spread-coded detected signals in response to a first spreading code of one or more spreading codes and the accumulated detected signals. [33] Control according to claim 32, wherein the first decoded spread-coded detected signal comprises at least two intermediate values ​​and the decoder is configured to integrate the first decoded spread-coded detected signal by adding the at least two intermediate values. [34] Control according to claim 33, wherein the decoder is configured to: Determining the second decoded spread-coded detected signals of the decoded spread-coded detected signals in response to a second spreading code of one or more spreading codes and the accumulated detected signals. [35] Control according to claim 34, wherein the second decoded spread-coded detected signal comprises at least two intermediate values ​​and the decoder is configured to integrate the second decoded spread-coded detected signal by adding the at least two intermediate values. [36] Control according to claim 30, wherein the processor is configured to determine touch information in response to one or more capacitive channel measurements. [37] Control according to claim 30, wherein the processor is configured to provide one or more spreading codes of an acquisition switching logic. [38] Capacitive sensing system, comprising: a sensor switching logic that includes sensing lines corresponding to channels of the capacitive sensing system; an encoder for encoding detected signals that indicate capacitances at the sensor switching logic, wherein the encoder is configured to perform encoding by: Spread coding of an initial detected signal in response to an initial spread code; and Spread coding of a second detected signal in response to a second spread code, where the first spreading code is orthogonal to the second spreading code and where each bit of the spreading code is either a logical one or a logical zero; an accumulator for accumulating spread-coded captured signals; a decoder for receiving spread-coded intermediate signals that indicate the contributions of the channels of the capacitive sensing system to the accumulated spread-coded sensing signals; and a digital logic for determining channel capacity measurements in response to coded intermediate signals. [39] System according to claim 38, wherein the decoder is configured to receive spread-coded intermediate signals indicating the contributions of the channels of the capacitive sensing system to the accumulated spread-coded sensing signals, by: Received, in response to an initial spreading code, a first spreading-coded intermediate signal indicating a contribution from a first channel of the capacitive sensing system to an accumulated spreading-coded detected signal; and Received, in response to a second spreading code, a second spread-coded intermediate signal indicating a contribution from a second channel of the capacitive sensing system to an accumulated spread-coded sensing signal. [40] System according to claim 39, wherein the first spreading code comprises a first group of bits and The second spreading code comprises a second group of bits. [41] A capacitive sensing system comprising: an encoder for encoding control signals in response to spreading codes, wherein each bit of the spreading codes is either a logic one or a logic zero, and wherein the encoder is configured to perform encoding by: Encoding an initial control signal in response to an initial spreading code; and Encoding a second control signal in response to a second spreading code, where the second spreading code is orthogonal to the first spreading code; a sensor switching logic for providing detected signals in response to spread-coded control signals; an accumulator for accumulating detected signals; a decoder for receiving spread-coded intermediate signals indicating the contributions of acquisition channels of the capacitive acquisition system to accumulated acquired signals accumulated over a number of acquisition cycles, wherein the decoder receives spread-coded intermediate signals indicating the contributions of the acquisition channels of the capacitive acquisition system to the accumulated acquired signals by: Received, in response to the first spreading code, a first spreading-coded intermediate signal indicating the contribution of a first channel of the capacitive sensing system to the accumulated sensing signals; and Received, in response to a second spreading code, a second spreading-coded intermediate signal indicating the contribution of a second channel of the capacitive sensing system to the accumulated sensing signals; and a digital logic for determining channel capacity measurements in response to coded intermediate signals.

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