Transmission of setpoint data to a light module

Abstract

The invention relates to a method for transmitting light setpoint data implemented in a control module comprising at least one Serial Peripheral Interface (SPI) capable of transmitting an SPI frame via a transmission port connected to a light module comprising a pixelated light source. The method comprises obtaining (601) a first set of light setpoint data and adapting (602) an SPI data frame. The adapted SPI data frame comprises a number of bits conforming to the SPI protocol, includes the first set of data, and is capable of being received and decoded by a receive port of a Universal Asynchronous Receiver Transmitter (UART). The adapted SPI data frame is transmitted (603) via the transmission port connected to the light module (FIG. 6).

Description

Title of the invention: Transmission of setpoint data to a light module

[0001] The present invention relates to the field of control of a light module comprising a pixelated light source, in particular for motor vehicles.

[0002] It is known to use pixelated light sources to perform many lighting functions, especially for display or lighting functions, particularly for motor vehicles.

[0003] The term “vehicle” means any type of vehicle such as a motor vehicle, a moped, a motorcycle, a bicycle, a storage robot, etc.

[0004] Pixelated light sources comprise a set of elementary light emitters that are individually controllable.

[0005] The control is ensured by a control unit integrated into the light module.

[0006] Such a control module receives setpoint data from a control module responsible for determining the images, or light frames or even photometries, to be displayed or projected by the light module, and for transmitting setpoint data to the control unit in order to produce such images.

[0007] For this purpose, the setpoint data can be transmitted via a wired connection between the control module and the light module.

[0008] Several communication protocols can be provided for the communication of setpoint data.

[0009] A UART protocol, for "Universal Asynchronous Receiver / Transmitter", is generally preferred for such communication, because it involves UART interfaces which are inexpensive, with in particular a single channel for transmitting setpoint data from a master entity to a slave entity.

[0010] In order to achieve increasingly complex lighting functions, with increasingly higher resolution, pixelated light sources include more and more elementary light emitters.

[0011] This is the case for certain pixelated light sources that are said to be monolithic in that they comprise individually controllable electroluminescent elements epitaxially mounted on a common substrate. Such monolithic pixelated light sources can comprise several thousand individually controllable electroluminescent elements.

[0012] This is also the case for pixelated light sources comprising electroluminescent elements in the form of discrete, i.e., distinct elements physically separate from each other, which can include several dozen or even several hundred electroluminescent elements.

[0013] In addition, light functions may now require a frequency of several tens of images per second, or even a hundred images per second.

[0014] Such a frequency and a high number of pixels of the light sources impose increasingly higher rates at the level of the communication of the setpoint data, in particular on the order of several tens of megabits per second.

[0015] The UART interface of most control modules is incapable of achieving such data rates, so the UART interface cannot be used for controlling the light module. However, it would be desirable to retain the aforementioned advantages of the UART protocol.

[0016] There is therefore a need to enable, at lower costs, the transmission of setpoint data at a high rate to a light module comprising a pixelated light source, in particular with a large number of pixels.

[0017] To this end, a first aspect of the invention relates to a method for transmitting light setpoint data implemented in a control module comprising at least one Serial Peripheral Interface, SPI, capable of transmitting an SPI frame via a transmission port connected to a light module comprising a pixelated light source, the method comprising the following steps: - obtaining a first set of light setpoint data; - adaptation of an SPI data frame, the adapted SPI data frame comprising a number of bits conforming to the SPI protocol, comprising the first set of data, and being capable of being received and decoded by a receive port of a Universal Asynchronous Receiver Transmitter, UART interface; - transmission of the adapted SPI data frame via the transmission port connected to the light module.

[0018] Thus, the present invention proposes to emulate a UART frame on an SPI interface of a control module. The SPI interface of most control modules allows high data rates, which makes it possible to control a light module with a pixelated light source having a large number of pixels, at a high frequency. Furthermore, it is possible for the light module to receive the setpoint data via a UART interface, which limits the costs associated with the transmission system. In particular, only one data transmission cable can be used between the control module and the light module.

[0019] According to some embodiments, the adapted SPI data frame may comprise a first part having a first number of bits conforming to the UART protocol, and a second part comprising a second number of padding bits, and a The sum of the first number of bits and the second number of bits can conform to the SPI protocol.

[0020] The padding bits are not detected by the light module, which makes the emulation transparent to the light module. Furthermore, such a format introduces an "overhead," or loss, at least corresponding to the padding bits (and to the start and end frame bits when present). However, in practice, such a loss is negligible compared to the throughput gains enabled by the invention.

[0021] In addition, the first part may include at least the first set of light setpoint data, a start bit and one or two stop bits.

[0022] The first part thus corresponds to a UART frame and is interpreted and decoded as such by the light module receiving the adapted SPI frame.

[0023] According to embodiments, the first data set can include between 6 and 10 bits of light setpoint data, in particular 8 bits of light setpoint data.

[0024] It is thus made possible to transmit at least 6 bits of setpoint data in each adapted SPI frame.

[0025] In addition, the adapted SPI frame can comprise 16 bits, the first part comprising 12 bits and the second part comprising 4 padding bits.

[0026] In practice, such an SPI frame adaptation allows for a low overhead compared to the gain in throughput caused by transmission on an SPI interface rather than on a UART interface.

[0027] According to embodiments, the first set may include the light setpoint data of a pixel of the pixelated light source of the light module, the control module may determine a second set including the light setpoint data of a light frame for all pixels of the pixelated light source, and the first set may be obtained from the second set.

[0028] Thus, each adapted SPI frame includes the setpoint data of a given pixel of the pixelated light source, and the construction of the adapted SPI frame and its transmission are thus facilitated.

[0029] In addition, the setpoint data of the second set may include a number of bits at least equal to the number of bits of the first set, multiplied by the number of pixels of the pixelated light source of the light module.

[0030] Thus, the invention is adaptable to any number of pixels of a pixelated light source, including for light sources comprising a large number of pixels, for example more than 1000 or even more than 10,000 pixels.

[0031] According to embodiments, the method may further include a configuration of a first clock speed of the SPI interface at a value between 90% and 110% of a second clock speed of a UART interface of the light module.

[0032] Thus, the clock port of the SPI interface of the control module can be disconnected, while allowing approximate synchronization of the clocks of the SPI and UART interfaces.

[0033] A second aspect of the invention relates to a computer program comprising instructions for implementing the method according to the first aspect of the invention, when these instructions are executed by a processor.

[0034] A third aspect of the invention relates to a control module comprising at least one Serial Peripheral Interface (SPI) capable of transmitting an SPI frame via a transmission port connected to a light module comprising a pixelated light source, the module further comprising: - a computing unit capable of obtaining data from a first set of lighting setpoints; and - an SPI data frame adaptation module, the adapted SPI data frame comprising a number of bits conforming to the SPI protocol, including the first set of data, and being capable of being received and decoded by a receive port of a Universal Asynchronous Receiver Transmitter (UART) interface. The transmission port is capable of transmitting the adapted SPI frame to the lighting module.

[0035] A fourth aspect of the invention relates to a light setpoint data transmission system comprising the control module according to the third aspect of the invention, and comprising a light module comprising: - a UART interface, with a receive port connected to the transmit port of the SPI interface of the control module; - a pixelated light source; - a control unit capable of controlling the pixelated light source according to the light setpoint data received in the adapted SPI frame.

[0036] Other features and advantages of the invention will become apparent from an examination of the detailed description below, and the accompanying drawings in which:

[0037] [Fig. la] illustrates a data transmission system using the UART protocol according to the prior art;

[0038] [Fig.lb] illustrates a data frame conforming to the UART protocol, according to the prior art;

[0039] [Fig.2] illustrates a data transmission system using the SPI protocol, according to prior art;

[0040] [Fig.3] illustrates a setpoint data transmission system for a light module with a pixelated light source, according to embodiments of the invention;

[0041] [Fig.4] illustrates a hardware configuration of an SPI module interface control and a UART 311 interface of a 311 light module, according to embodiments of the invention;

[0042] [Fig.5] illustrates an SPI frame adapted for transmission to a UART interface, according to embodiments of the invention;

[0043] [Fig.6] illustrates a method of transmitting setpoint data from a control module to a light module with a pixelated light source, according to embodiments of the invention.

[0044] The description focuses on the features that distinguish the system and control module from those known in the state of the art.

[0045] Fig. 1a illustrates a data transmission system using the UART protocol, according to the prior art.

[0046] The system comprises a master device 100 and a slave device 110.

[0047] The master device 100 includes an interface adapted to the UART protocol comprising: - a transmission port 101, capable of transmitting data frames conforming to the UART protocol; - a receive port 102 capable of receiving data frames conforming to the UART protocol; - a ground port 103 suitable for connection to ground.

[0048] The slave device 110 includes an interface adapted to the UART protocol comprising: - a receive port 111 capable of receiving data frames conforming to the UART protocol; - a transmission port 112 capable of transmitting data frames conforming to the UART protocol; - a ground port 113 suitable for connection to ground.

[0049] The transmission port 101 can be connected, by wire, to the reception port 111 for transmission of UART frames from the master device 100 to the slave device 110.

[0050] The receiving port 102 can be connected, by wire, to the transmitting port 112 for the transmission of UART frames from the slave device 110 to the master device 100.

[0051] Since no clock signal is shared between the master device 100 and the slave device 110, the UART protocol is asynchronous.

[0052] Figure [Fig.lb] shows the format of a 120 data frame conforming to the UART protocol, or UART frame hereafter, according to the prior art.

[0053] The UART 120 frame includes: - 1 starting bit 121; - 5 to 9 bits of data 122; - 0 to 1 parity bit 123. In other words, parity bit 123 is optional. Such a parity bit 123 allows for the detection of an error in a received frame, in a well-known way; - 1 to 2 stop bits or stop 124.

[0054] Thus, a UART frame comprises between 7 and 13 bits.

[0055] In [Fig. 1b], the bits of the UART 120 frame are scanned from left to right, starting with the most significant bit (MSB). Alternatively, the UART 120 frame can be reversed for reading from right to left, starting with the least significant bit (LSB).

[0056] Figure 2 illustrates a data transmission system using the SPI protocol, according to earlier art.

[0057] The SPI protocol refers to "Serial Peripheral Interface" and is implemented between a master device 200 and at least one slave device. In [Fig. 2], a transmission system with three slave devices 210.1, 210.2 and 210.3 is shown for illustrative purposes only.

[0058] The master device 200 includes an interface adapted to the SPI protocol and comprising: - a clock signal port 201 capable of transmitting a clock signal from the master device 200 to the slave devices 210.1-210.3; - a transmission port 202, called MOSI for "Master Output Slave Input" capable of transmitting data from the master device to the slave devices 210.1-210.3; - a receive port 203, called MISO for "Master Input Slave Output" capable of receiving data from slave devices 210.1-210.3; - three slave selection ports 204, 205 and 206 capable of transmitting a slave selection signal to slave devices 210.1-210.3.

[0059] Due to the exchange of a clock signal, the data exchanges between the master device 200 and the slave devices 210.1-210.3 are synchronous.

[0060] Each of the slave devices 210.1, 210.2 and 210.3 includes an interface comprising the following ports, described for the first slave device 210.1 by way of illustration: - a clock signal receiving port 211.1 capable of receiving the clock signal from the clock signal port 201 described previously. For this purpose, the port of Clock signal receiver 211.1 is connected by wire to clock signal port 201. The same applies to the clock signal receiver ports of the other slave devices, which are connected by wire to clock signal port 201; - a receive port 212.1, called MOSI, and connected, by wire, to the MOSI port 202 of the master device 200. Each receive MOSI port of the other slave devices 210.2 and 210.3 is also connected by wire to the MOSI port 202 of the master device 200; - a transmission port 213.1, also called MISO, and connected, by wire, to the MISO port 203 of the master device 200. Each MISO transmission port of the other slave devices 210.2 and 210.3 is also connected by wire to the MISO port 203 of the master device 200; - a selection signal receiving port 214.1 capable of receiving a selection signal from the slave selection port 204 of the master device, via a wired connection. The selection signal receiving port of the second slave device 210.1 is connected via a wired connection to the slave selection port 205, and the selection signal receiving port of the third slave device 210.3 is connected via a wired connection to the slave selection port 206.

[0061] A data frame conforming to the SPI protocol, referred to as an SPI frame in the following: - includes a configurable number of data bits, for example between 2 and 32 bits on some microprocessors used as a master device 200; - includes an optional parity bit, therefore between 0 and 1 parity bit; - includes a configurable clock polarity, between the values ​​0 and 1 for example; - includes a configurable phase polarity, between the values ​​0 and 1 for example; - allows you to configure a frame transmission direction, indicating whether the LSB is transmitted first or whether the MSB is transmitted first.

[0062] Most microprocessors including an SPI interface are capable of transmitting data at high rates, in particular at rates of several tens of megabits per second, due to the synchronization of clocks.

[0063] Figure 3 presents a light setpoint data transmission system according to embodiments of the invention.

[0064] The system includes a control module 300, having the role of master device, and a light module 310, having the role of slave device.

[0065] The system can thus be integrated into a motor vehicle, the light module 310 fulfilling a lighting function of the vehicle, such as: - a display function, for example inside the vehicle, or for signaling purposes outside the vehicle; - a lighting function, such as a low beam (LB) or high beam (HB) function, outside the vehicle, the light module 310 being able to be integrated into a lighting device at the front of the vehicle.

[0066] In what follows, it is considered by way of illustration that the light module 310 is integrated into a motor vehicle lighting device.

[0067] The light module 310 includes a pixelated light source 313. In this document, a pixelated light source 313 is defined as a light source comprising a plurality of n individually controllable elementary light emitters 314, n being an integer greater than or equal to 2, preferably greater than 10, or even greater than 100, or greater than 1000 or 10,000. The n elementary light emitters 314 can be arranged in at least two rows and / or at least two columns. For example, the elementary light emitters 134 can be arranged in a matrix with at least two rows and / or at least two columns.

[0068] In the example of [Fig.3], a pixelated light source comprises 6 columns and 6 rows of elementary light emitters 134 forming 36 pixels.

[0069] Thus, the larger n is, the higher the resolution of the image displayed or projected by the light module 310.

[0070] The elementary light emitters 314 can be electroluminescent elements, also referred to as electroluminescent elements in the following. In this case, the electroluminescent elements can be in the form of discrete elements, that is to say, physically distinct from one another.

[0071] Examples of electroluminescent elements of this type include the light-emitting diode or LED (English acronym for "Light Emitting Diode"), the organic light-emitting diode or OLED (English acronym for "Organic Light-Emitting Diode"), or the polymer light-emitting diode or PLED (English acronym for "Polymer Light- Emitting Diode").

[0072] Such LEDs may have at least one dimension in millimeter size, or even in micrometer size. For example, microLEDs or miniLEDs all have dimensions less than 1 mm, or even less than 200 micrometers.

[0073] Alternatively, the elementary electroluminescent light emitters 314 are grown from a common substrate and are electrically connected so as to be individually controllable. The common substrate may comprise at least one semiconductor layer having an active area for generating the corresponding light by electroluminescence. The substrate may comprise one or more other materials, for example, non-semiconductors. Thus, each elementary emitter or group of elementary emitters can form a A luminous pixel can emit light when its material is powered by electricity. This type of light source is called a monolithic light source and has the advantage of having its elementary emitters very close together compared to conventional light-emitting diodes.

[0074] In view of the progress in the development of pixelated light sources to date, a pixelated light source is considered high-resolution when the number of elementary light emitters is at least 20. This definition is based on the document below, which traces the evolution of high-resolution pixelated light sources:

[0075] Wang Li ping ET AL: “High-Resolution Pixel LED Headlamps: Functional Requirement Analysis and Research Progress”, Applied Sciences, vol.ll, no.8, 9 April 2021 (2021-04-09), page 3368, XP055916448, DOI: 10.3390 / app 11083368.

[0076] In an example of a high-resolution monolithic pixelated light source, the number of elementary light emitters can be on the order of 20,000 emitters.

[0077] A so-called "monolithic" light source can exhibit a particularly high density of light elements, making it especially attractive for a wide range of applications. A monolithic light source involves a plurality of submillimeter-sized electroluminescent semiconductor elements epitaxially mounted directly onto a common substrate, the substrate generally being made of silicon. Unlike conventional LED arrays, in which each elementary light source is an individually produced electronic component mounted on a substrate such as a printed circuit board (PCB), a monolithic light source is considered a single electronic component, during the production of which several arrays of electroluminescent semiconductor junctions are generated on a common substrate, in the form of an array.This production technique allows for the creation of electroluminescent areas, each acting as an elementary light source, placed very close together. The gaps between the elementary sources can be submillimeter in size. One advantage of this production technique is the high pixel density that can be achieved on a single substrate.

[0078] In what follows, the example of electroluminescent light elements is considered, by way of illustration. The individually controllable electroluminescent elements 314 are also referred to as pixels in what follows.

[0079] The light module 310 further includes a control unit 312 for the pixelated light source 313, capable of individually controlling the pixels of the pixelated light source according to light setpoint data.

[0080] The control unit 312 can be an integrated circuit enabling the control of the power supply to the pixels 314 of the pixelated light source 313.

[0081] The control unit 312 can be mounted on the same support as the pixelated light source 313. The control unit 312 can also be partially or totally integrated into the same substrate as the pixelated light source 313.

[0082] The driver unit 312 can be an ASIC type integrated circuit, for "Application Specified Integrated Circuit" in English.

[0083] When the light source 313 includes discrete LEDs 314, for example miniLEDs or microLEDs, the control unit 312 can: - control the LEDs 314 via active matrices: in this case an individual current source is provided for each LED 314, and activation / deactivation commands for the individual current sources are sent by the control unit 312 according to the setpoint data received; - Control the 314 LEDs via passive matrices: in this case, an individual current source can be provided for each row and a common voltage source for each column. The LEDs are alternately activated by selectively controlling the current and voltage sources according to received setpoint data.

[0084] Active matrix and passive matrix control elements 312 are well known and are not further detailed in the present description.

[0085] In the case of a projection module 310 integrated into a lighting device and thus performing at least one lighting function, the projection module 310 may further include an optical projection system capable of projecting the light rays from the pixelated light source 313, the optical projection system not being shown in [Fig.3].

[0086] The control module 300 may include a setpoint data processing unit 301. The setpoint data may be determined by the unit 301 based on commands received from a central vehicle control module, not shown in [Fig. 3], which may be a BCM (Body Controller Module). Alternatively, the unit 301 determines the setpoint data based on information from other modules, from sensors, and / or from communication interfaces. Alternatively, the setpoint data may be predetermined and stored in a memory 304 of the control module 300.

[0087] The received commands may indicate light patterns, that is, matrix distributions of light intensity, which may be: - a series of lighting photometries received at given time intervals, for projection of lighting photometries; - a series of video frames for displaying video frames.

[0088] We distinguish between light frames which correspond to images or matrix distributions of light intensity, and data frames according to the UART and SPI protocols, which are sets of bits of a given size.

[0089] In what follows, it is considered, by way of illustration, that the control module 300 is capable of receiving commands from a BCM type control module, and that the calculation unit 301 is capable of determining setpoint data on the basis of the commands received.

[0090] The control module 300 can be integrated anywhere in the motor vehicle, between the BCM control module and the light module 310.

[0091] For example, the control module 300 can be integrated into the lighting device, with the lighting module 310, which has the advantage of limiting interference on the cable carrying the setpoint data between the control module 300 and the lighting module 310.

[0092] Alternatively, the control module 300 can be outside the lighting device, near the BCM control module.

[0093] The control module 300 includes an SPI interface 303 conforming to the interface 200 shown in [Fig.2], and capable of transmitting SPI frames.

[0094] In the prior art, a computing unit is capable of integrating setpoint data into SPI frames for transmission to a slave SPI 303 interface. However, according to the prior art, such an SPI frame is not interpretable by a UART interface such as the UART 311 interface of the light module 310. The prior art thus requires equipping the light module 310 with an expensive SPI interface to allow the transfer of setpoint data at a high rate.

[0095] According to the invention, the control module 300 comprises an adaptation module 302, capable of receiving setpoint data, in the form of a series of setpoint bits, and capable of generating an adapted SPI frame including setpoint data, the adapted SPI frame being capable of being received by the UART interface 311 of the light module 310.

[0096] In addition, the SPI interface 303 of the control module is configured and wired so as to be connected to the UART interface 311 of the light module 310.

[0097] It is thus made possible to transmit setpoint data at a high rate by a control module 300, while allowing reception of setpoint data by a light module 310 equipped with an inexpensive UART interface.

[0098] The adaptation module 302 can be a hardware module in interception between the computing unit 301 and the SPI interface 303. In this case, the computing unit 301 is able to transmit setpoint data to the adaptation module 302, in the form of a series of setpoint data bits, and an SPI frame is generated by the adaptation module 302.

[0099] Alternatively, the adaptation module 302 is a software module that can be integrated into the computing unit 301. In this case, the computing unit transmits an SPI frame adapted by the adaptation module 302, to the SPI interface 303.

[0100] The adaptation of the SPI frame by the adaptation module 302 allows the emulation of a UART frame on an SPI interface, and such an adaptation will be detailed in the description of [Fig.5].

[0101] The control module 300 can be a microprocessor, the unit 301, the adaptation module 302 and the SPI interface 303 being integrated into the microprocessor.

[0102] The control module 300 may also include a UART interface, not shown in [Fig.3]. However, in such a case, the UART interface is not connected to the light module 310, since most microprocessors including such a UART interface are incapable of transmitting setpoint data at high rates, in particular exceeding one megabyte per second.

[0103] Figure 4 shows the hardware configuration of the SPI 303 interface of the control module 300 and the UART 311 interface of the lighting module 310, enabling the emulation of a UART frame, which is an SPI frame adapted according to the invention, on the SPI interface. The hardware configuration refers to the wiring and configuration of the various ports of the SPI 303 and UART 311 interfaces.

[0104] As shown in [Fig.4], the SPI 303 interface is configured in hardware as follows: - a MOSI port 401 is connected to a receive port 411 of the UART interface, by a cable 420 capable of carrying the adapted SPI frames from the control module 300 to the lighting module 310; - a MISO 402 port is disconnected, that is, it is not connected to any other port; - a 403 clock port is disconnected, i.e., not connected to any other port; - a slave select port 404 is connected to ground, for example wired to a ground port 405.

[0105] On the receiver side, the UART 311 interface of the 310 light module is configured in hardware as follows: - as indicated above, the receive port 411 is connected to the MOSI port 401 of the SPI interface 303 of the control module 300; - a 412 transmission port that is disconnected, i.e., not connected to any other port; - a 413 ground port connected to ground.

[0106] Figure [Fig. 5] illustrates an SPI frame adapted 510 by a control module 300 according to embodiments of the invention.

[0107] A set of 500 setpoint data is obtained by the computing unit 301 described above. The set of 500 may, for example, comprise 8 bits of setpoint data.

[0108] The set 500 is integrated by the adaptation module 302 into an adapted SPI frame 510 which can be obtained by the following configuration: - the transmission direction is configured from the LSB for example; - The size of the adapted SPI frame is configured to have the size of a UART frame, when 504 padding bits are ignored. For example, the adapted SPI frame may comprise 16 bits, including a first part of 12 bits emulating a UART frame, and a second part comprising 4 504 padding bits; - the first part emulating a UART frame can include a start bit 501, the set 500 of data bits, comprising 8 bits in this example, a parity bit 502 and two end or stop bits 503. A different distribution can be provided according to the invention, the person skilled in the art being able to determine the structure of the adapted frame 510 according to the size of the set 500 of instruction data transmitted in each frame, and according to the format of a UART frame.

[0109] Figure 6 illustrates a method of transmitting setpoint data from a control module to a light module, according to embodiments of the invention.

[0110] The method can be implemented in the control module 300 described above.

[0111] At a step 600, a hardware configuration of the control module 300 is implemented, including a hardware configuration of the SPI interface 303. The hardware configuration may include, as previously described, connecting a MOSI port 401 of the SPI interface 303 to the receive interface 411 of the UART interface 311 of the light module 310. Ports 402 and 403 are not connected to any other port during the hardware configuration, and the slave select port 404 is connected to ground. In addition, step 600 may include all or part of the following elements of the SPI protocol configuration of the master device 200: - fixing a transmission direction for the SPI frame originating from the LSB, so as to maintain an order for sending the bits of the setpoint data; - absence of parity bit, so as not to introduce an additional bit which would be interpreted (erroneously) upon reception; - fixing the clocks to a high polarity, so as not to reverse the transmitted signal; - Synchronization of the SPI clock to a value close to the clock of the slave device 210, for example between 90% and 110% of the clock frequency of the slave device 210.

[0112] At a step 601, a first set of setpoint data is obtained by the control module 300, for example by the calculation unit 301. As described previously, in some embodiments, the calculation unit 301 can determine the setpoint data based on a command received from a BCM control module.

[0113] No restrictions are attached to the setpoint data, nor to the quantity of setpoint data of the first set obtained in step 601.

[0114] The first set can, for example, be a byte, i.e., 8 bits, from a second, larger set of instruction data corresponding to the instruction for an entire light frame. The byte from the first set can then encode the light instruction for a given pixel of the light frame. A light frame, as described above, is understood to be an element of a sequence of elements that together form a light animation, to be displayed or projected by the light module.

[0115] The setpoint data of the second set can thus correspond to setpoint data for an entire image, or video frame, to be displayed or projected by the light module 310, in which case the amount of setpoint data in the second set depends on the number of pixels of the pixelated light source 313, and the granularity associated with the brightness of each pixel. In order to allow for a granularity better than a binary "on" / "off" granularity for the setpoint of each pixel, pulse-width modulation, or PWM, control can be implemented by the previously described driver unit 312.

[0116] By way of example, a pixelated light source 313 comprising 25600 pixels, i.e. 320 rows and 80 columns of pixels, is considered.

[0117] In this case, for each video frame, that is, for each instruction enabling the light module 310 to display or project a given image, and considering that the instruction for each pixel 314 is encoded on one byte, i.e., 8 bits, the processing unit 301 is capable of determining a second set of at least 25,600 bytes. However, there is no restriction on the number of bits in the first set encoding the light instruction for each pixel 314 of the pixelated light source 313.

[0118] The instruction for each video frame, i.e. the second set, may however include more than 25600 bytes, in order to add control bits, for example: - 4 bytes to indicate the start of a new video frame; - 4 bytes of cyclic redundancy check, or CRC for "Cyclic Redundancy Check" in English.

[0119] In this case, the second set comprises 25608 bytes of setpoint data.

[0120] At step 602, the adaptation module 302 determines an adapted SPI frame based on the setpoint data from the first set obtained at step 601. As described previously, the adapted SPI frame is a data frame: - adapted for transmission via an SPI interface; and - adapted to be received by the UART 311 interface and interpreted as a UART frame by the light module 310 including the UART 311 interface.

[0121] Thus, the adapted SPI frame allows emulation of a UART frame on an SPI interface.

[0122] At step 603, the adapted SPI frame determined at step 602 is transmitted by the control module 300 via the SPI interface 303, in particular via the previously described MOSI 401 transmission port.

[0123] At step 604, the control module 300 determines whether the second set includes another first set of data that has not yet been transmitted. In other words, in the example considered here, the control module 300 determines whether at least one byte of setpoint data from the second set encoding the current light frame, that is, the light frame being transmitted, has not been transmitted to the light module 310.

[0124] If the second set includes at least one other first set that has not yet been transmitted, the transmission process is repeated from step 601 and said other first set of data is obtained at step 601. Another adapted SPI frame is determined at step 602 on the basis of the other first set, and the other adapted SPI frame is transmitted at step 603.

[0125] If the second set does not include any other first set that has not yet been transmitted, that is, if all the setpoint data for the second set has been transmitted to the light module 310, the setpoint data transmission process ends at step 605. However, the transmission process can continue with the transmission of setpoint data for a new second set, encoding the setpoint for a subsequent video frame. In this case, the process is also iterated from step 601 for the new second set.

[0126] When the adaptation module 302 is a software module, as described previously, steps 601 to 604 can be implemented by executing instructions from a computer program by a processor of the control module 300, for example by a processor of the computing unit 301. The computer program can be stored in a memory of the control module 300.

[0127] The present invention is not limited to the embodiments described above by way of example; it extends to other variants.

Claims

Demands

1. A method for transmitting light setpoint data implemented in a control module (300) comprising at least one Serial Peripheral Interface, SPI, capable of transmitting an SPI frame via a transmission port (401) connected to a light module (310) comprising a pixelated light source (313), the method comprising the following steps: - obtaining (601) a first set (500) of light setpoint data; - adapting (602) an SPI data frame, the adapted SPI data frame (510) comprising a number of bits conforming to the SPI protocol, comprising the first set of data, and being capable of being received and decoded by a receive port (411) of a Universal Asynchronous Receiver Transmitter, UART (311); - transmitting (603) the adapted SPI data frame via the transmission port connected to the light module., the Serial Peripheral Interface (303) of the control module being characterized in that it comprises: - a MOSI port (401), - a MISO port (402) left disconnected, - a clock port (403) left disconnected, - a slave selection port (404) connected to ground; the UART interface (311) of the light module (310) being characterized in that it further comprises: - a transmit port (412) left disconnected, - a ground port (413) connected to ground, - a receive port (411) the MOSI port (401) being connected to a receive port (411) of the UART interface, by a cable (420) capable of carrying the adapted SPI frames from the control module (300) to the light module (310).

2. A method according to claim 1, wherein the adapted SPI data frame (510) comprises a first part (500; 501; 502; 503) having a first number of bits conforming to the UART protocol, and a second part (504) comprising a second number of padding bits, in which a sum of the first number of bits and the second number of bits conforms to the SPI protocol.

3. A method according to claim 2, wherein the first part (500; 501; 502; 503) comprises at least the first set (500) of light setpoint data, a start-of-frame bit (501) and one or two stop bits (503).

4. A method according to any one of the preceding claims, wherein the first set (500) of data comprises between 6 and 10 bits of light setpoint data, for example 8 bits of light setpoint data.

5. A method according to claim 3 and claim 4, wherein the adapted SPI frame (510) comprises 16 bits, the first part (500; 501; 502; 503) comprising 12 bits and the second part (504) comprising 4 padding bits.

6. A method according to any one of the preceding claims, wherein the first set (500) comprises the light setpoint data of a pixel (314) of the pixelated light source (313) of the light module (310), wherein the control module (300) determines a second set comprising the light setpoint data of a light frame for all pixels of the pixelated light source, and wherein the first set is obtained from the second set.

7. A method according to claim 6, wherein the setpoint data of the second set comprises a number of bits at least equal to the number of bits of the first set (500), multiplied by the number of pixels (314) of the pixelated light source (313) of the light module (310).

8. A method according to any one of the preceding claims, further comprising a configuration of a first clock speed of the SPI interface (303) at a value between 90% and 110% of a second clock speed of a UART interface (311) of the light module (310).

9. A computer program comprising instructions for carrying out the method according to any one of the preceding claims, when such instructions are executed by a processor.

10. Control module comprising at least one Serial Peripheral Interface (303), SPI, capable of transmitting an SPI frame via a transmission port (401) connected to a light module (310) comprising a pixelated light source (313), the control module further comprising: - a processing unit (301) capable of obtaining a first set (500) of light setpoint data; and - an adaptation module (302) capable of obtaining an adapted SPI data frame (510) comprising a number of bits conforming to the SPI protocol, comprising the first set of data, and being capable of being received and decoded by a receive port (411) of a Universal Asynchronous Receiver Transmitter (311), UART interface; wherein the transmission port is capable of transmitting the adapted SPI frame to the light module, the Serial Peripheral Interface (303) of the control module being characterized in that it comprises: - a MOSI port (401), - a MISO port (402) left disconnected, - a clock port (403) left disconnected, - a slave selection port (404) connected to ground;the UART interface (311) of the light module (310) being characterized in that it further comprises: - a transmission port (412) left disconnected, - a ground port (413) connected to ground, - a receive port (411) the MOSI port (401) being connected to a receive port (411) of the UART interface, by a cable (420) capable of carrying the adapted SPI frames from the control module (300) to the light module (310).;

11. Light setpoint data transmission system comprising the control module (300) according to claim 10, and comprising a light module (310), the light module comprising: - a UART interface (311), with a receive port (411) connected to the transmit port (401) of the SPI interface (303) of the control module (300); - a pixelated light source (313); - a control unit (312) capable of controlling the pixelated light source according to the light setpoint data received in the adapted SPI frame (510).

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