Pressure data acquisition circuit

Abstract

The utility model provides a pressure data acquisition circuit, and belongs to the technical field of pressure measurement. Comprising a pressure sensor module, a first switch module, a second switch module and an MCU module. The pressure sensor module comprises a piezoresistive layer, and a first electrode and a second electrode which are attached to the two sides of the piezoresistive layer; the first electrodes are arranged in parallel at equal intervals, the second electrodes are arranged in parallel at equal intervals, and the first electrodes are perpendicular to the second electrodes; each group of first electrodes is provided with one first switch module in a matched manner, and the first electrodes in each group are electrically connected with switch ports of the corresponding first switch modules in a one-to-one manner; each group of second electrodes is provided with one second switch module in a matched manner, and the second electrodes in each group are electrically connected with the switch ports of the corresponding second switch modules in a one-to-one manner. According to the utility model, pressure values of a large number of point locations can be acquired under the condition that only one available analog input port is provided.

Description

Technical Field

[0001] The utility model belongs to the technical field of pressure measurement, and in particular relates to a pressure data acquisition circuit. Background Art

[0002] At present, researchers often use piezoresistive sensor arrays to measure individual posture pressure data. For example, patent document CN208721291U proposes a flexible resistive pressure sensor array, including a surface packaging layer, an electrode layer and a functional layer. The electrode layer includes a base film and a plurality of equidistantly arranged thin film metal wires on the base film, and the thin film metal wires are connected to a multi-way selector; the flexible elastic film is covered with a plurality of equidistantly arranged conductive metal wires, and the thin film metal wires of the electrode layer and the conductive metal wires of the functional layer are overlapped and assembled in a vertically crossed manner.

[0003] In order to collect more detailed pressure data and achieve large-scale and high-density pressure data collection, the sensor array needs to set up a large number of pressure collection points. Some experiments require hundreds or even more than a thousand pressure collection points. The current piezoresistive pressure collection circuit mostly uses the analog input port of the MCU chip to collect voltage data to evaluate the pressure data, but the number of analog input ports of the MCU chip is limited, and it is impossible to directly collect voltage data at a large number of points. Utility Model Content

[0004] The utility model aims to solve the technical problem that the current MCU chip cannot directly collect voltage data of a large number of points, and provides a pressure data collection circuit.

[0005] The technical solution adopted by the utility model is:

[0006] A pressure data acquisition circuit comprises a pressure sensor module, a first switch module, a second switch module and an MCU module;

[0007] The pressure sensor module comprises a piezoresistive layer and a first electrode and a second electrode attached to both sides of the piezoresistive layer; a plurality of the first electrodes are arranged in parallel and at equal intervals, a plurality of the second electrodes are arranged in parallel and at equal intervals, and the first electrode and the second electrode are perpendicular to each other;

[0008] The first electrodes are divided into a plurality of groups according to the position sequence, each group of the first electrodes is equipped with a first switch module, and the first electrodes in each group are electrically connected to the switch ports corresponding to the first switch modules one by one; the second electrodes are divided into a plurality of groups according to the position sequence, each group of the second electrodes is equipped with a second switch module, and the second electrodes in each group are electrically connected to the switch ports corresponding to the second switch modules one by one;

[0009] The common ports of the first switch modules are electrically connected to the voltage source, and the common ports of the second switch modules are electrically connected to the analog input ports of the MCU module; the controlled ports of the first switch modules and the controlled ports of the second switch modules are electrically connected to the control ports of the MCU module respectively.

[0010] Furthermore, the pressure sensor module further includes a first protective layer and a second protective layer, wherein the first protective layer is disposed on the outer side of the first electrode and is bonded to the piezoresistive layer, and the second protective layer is disposed on the outer side of the second electrode and is bonded to the piezoresistive layer.

[0011] Furthermore, the outer side of the pressure sensor module is also wrapped with an integral silicone layer.

[0012] Furthermore, the pressure sensor module is provided with vias in the gap between the first electrode and the second electrode along the thickness direction.

[0013] Furthermore, it also includes a power module, a storage module and a communication module; the power module is used to provide electrical energy; the storage module is used to store the collected voltage data or pressure data; and the communication module is used to communicate with external devices.

[0014] Furthermore, the first electrode and the second electrode are both linear or strip-shaped and have the same width.

[0015] Furthermore, the number of the first electrodes in each group is 4-16, and the number of the second electrodes in each group is 4-16.

[0016] Furthermore, the first switch module and the second switch module each have 16 switch ports.

[0017] Furthermore, the models of the first switch module and the second switch module are both CD74HCx4067.

[0018] Further, the number of the first switch modules and the number of the second switch modules are both 4, and the number of electrodes in each group of the first electrodes and the number of electrodes in each group of the second electrodes are both 16.

[0019] Furthermore, the MCU module includes an MCU chip of model STM32F103VET6.

[0020] Compared with the prior art, the utility model has the following beneficial effects:

[0021] The utility model can collect pressure values ​​of a large number of points even when the MCU module has only one available analog input port. The pressure sensor module of the utility model can be made into a thin film shape, can be bent for use, and has a wide range of application scenarios; at the same time, an integrated silicone layer can be set on the outside of the pressure sensor module to protect the internal electrodes and increase the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The utility model is further described in detail below in conjunction with the accompanying drawings.

[0023] Figure 1 : A schematic diagram of the structure of a pressure sensor module in Embodiment 1 of the present utility model;

[0024] Figure 2 : Electrical connection diagram of the pressure sensor module of Example 1 of the utility model;

[0025] Figure 3 : Schematic diagram of the pressure sensor module of Example 1 of the utility model;

[0026] Figure 4 : A schematic structural diagram of Embodiment 1 of the present utility model;

[0027] Figure 5 : A schematic diagram of the structure of a pressure sensor module according to Embodiment 2 of the present utility model;

[0028] Figure 6 : One of the structural schematic diagrams of the pressure sensor module of Embodiment 3 of the present utility model;

[0029] Figure 7 : The second structural diagram of the pressure sensor module of Embodiment 3 of the present utility model;

[0030] Figure 8 : A partial cross-sectional view of a pressure sensor module according to Embodiment 3 of the present utility model;

[0031] Among them: 1-pressure sensor module, 11-first protective layer, 12-piezoresistive layer, 13-second protective layer, 14-first electrode, 15-second electrode, 16-silicone layer, 21-first switch module, 22-second switch module, 3-MCU module, 4-power module, 5-storage module, 6-communication module. DETAILED DESCRIPTION

[0032] In order to better understand the present invention, the content of the present invention is further clearly described below in conjunction with the embodiments and drawings, but the protection content of the present invention is not limited to the following embodiments. In the following description, a large number of specific details are given in order to provide a more thorough understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without one or more of these details.

[0033] Example 1: See Figure 1-Figure 4 The purpose of this embodiment is to provide a pressure data acquisition circuit, including a pressure sensor module 1 and an MCU module 3.

[0034] The pressure sensor module 1 comprises a first protective layer 11, a piezoresistive layer 12 and a second protective layer 13, wherein the piezoresistive layer 12 is bonded between the first protective layer 11 and the second protective layer 13. The piezoresistive layer 12 has an obvious piezoresistive effect, and its resistance changes when subjected to pressure.

[0035] A plurality of parallel and equally spaced first electrodes 14 are bonded between the first protective layer 11 and the piezoresistive layer 12, and a plurality of parallel and equally spaced second electrodes 15 are bonded between the second protective layer 13 and the piezoresistive layer 12. The first electrode 14 and the second electrode 15 are both linear or strip-shaped, have the same width, and are perpendicular to the first electrode 14. The intersection of the first electrode 14 and the second electrode 15 is the pressure collection point.

[0036] The first electrodes 14 are divided into multiple groups according to the position sequence, and the number of first electrodes 14 in each group is 4-16. The second electrodes 15 are divided into multiple groups according to the position sequence, and the number of second electrodes 15 in each group is 4-16. Each group of first electrodes 14 is equipped with a first switch module 21, and each group of second electrodes 15 is equipped with a second switch module 22.

[0037] Specifically, the first switch module 21 has switch channels that are not less than the number of the first electrodes 14 in each group, and the first electrodes 14 in each group are electrically connected to the switch ports of the first switch module 21 one by one in position sequence. The second switch module 22 has switch channels that are not less than the number of the second electrodes 15 in each group, and the second electrodes 15 in each group are electrically connected to the switch ports of the second switch module 22 one by one in position sequence.

[0038] At the same time, the common ports of the first switch module 21 are electrically connected to the voltage source VCC, and the common ports of the second switch module 22 are electrically connected to the ADC (analog input) port of the MCU module 3. The controlled ports of the first switch module 21 and the controlled ports of the second switch module 22 are electrically connected to the control ports (such as GPIO ports) of the MCU module 3, respectively.

[0039] When the utility model is working, the MCU module 3 controls the on or off of the first switch module 21 and the second switch module 22, firstly turns off all the switch ports of the first switch module 21 and the second switch module 22, then turns on one switch port of the first switch module 21 in the order of position, so that the corresponding first electrode 14 is turned on with the voltage source, then turns on the switch ports of the second switch module 22 in sequence (only one switch port is turned on each time, and the other switch ports are turned off), after the switch port of the second switch module 22 is turned on, the corresponding second electrode 15 is turned on with the ADC port of the MCU module 3, and the corresponding voltage value is collected using the ADC port; then turns on the next switch port of the first switch module 21, and turns on the switch port of the second switch module 22 in sequence to collect the voltage value. By cyclically turning on and off the switch ports of the first switch module 21 and the second switch module 22, the voltage value of each pressure collection point can be collected, and the change of the voltage value relative to the VCC voltage reflects the pressure received. By sequentially conducting the first electrode 14 and the second electrode 15 , it is prevented that the other first electrodes 14 and the second electrodes 15 around the target pressure collection point may be conducted or powered on to affect the accuracy of the collected voltage value.

[0040] The MCU module 3 is used to obtain the corresponding pressure value according to the collected voltage value based on the preset relationship between pressure and voltage value.

[0041] The first switch module 21 and the second switch module 22 are both multiplexers. Preferably, the first switch module 21 and the second switch module 22 are both CD74HCx4067, with 16 switch ports, and the on or off speed of the switch ports is less than 500ns.

[0042] Preferably, the MCU module 3 includes an MCU chip of model STM32F103VET6.

[0043] Preferably, four first switch modules 21 , four second switch modules 22 , four groups of first electrodes 14 and four groups of second electrodes 15 are provided in total, and the number of electrodes in each group of first electrodes 14 and second electrodes 15 is 16.

[0044] like Figure 4 An embodiment is provided, wherein the acquisition circuit further comprises a power module 4, a storage module 5 and a communication module 6. The power module 4 is used to provide electrical energy and comprises a lithium-ion battery. The MCU module 3 stores the voltage data acquired by the pressure sensor module 1 in the storage module 5 through the SPI protocol; preferably, the storage module 5 comprises a memory card. The communication module 6 is used to communicate with an external device and transmit the acquired voltage data or pressure data, or the voltage data or pressure data stored in the storage module 5 to the external device; preferably, the communication module 6 comprises a Bluetooth serial communication module of model HC05.

[0045] Example 2: See Figure 5 Compared with Example 1, the pressure data acquisition circuit provided in this embodiment mainly makes the following improvements: the outer side of the pressure sensor module 1 is wrapped with an integral silicone layer 16 .

[0046] By encapsulating the pressure sensor module 1 with silica gel, the service life of the pressure sensor module 1 can be increased.

[0047] Example 3: See Figure 6-Figure 8 Compared with Embodiment 1 or Embodiment 2, the pressure data acquisition circuit provided in this embodiment mainly makes the following improvements: the pressure sensor module 1 adopts a hollow structure.

[0048] Specifically, the pressure sensor module 1 is provided with hollow via holes in the gap between the first electrode 14 and the second electrode 15 along the thickness direction, so that the pressure sensor module 1 forms a hollow structure. Preferably, the via holes are square holes. At the same time, the outer side of the pressure sensor module 1 is also wrapped with a silicone layer 16.

[0049] like Figure 6 Schematic diagram of the positions of the first protective layer 11, the first electrode 14, the piezoresistive layer 12, the second electrode 15 and the second protective layer 13. Figure 7 This is a schematic diagram of the structure after the five parts are fitted together. Figure 8 is Figure 7 A silicone layer 16 is wrapped around the base of the structure shown.

[0050] The pressure sensor module 1 adopts a hollow design and is provided with a silicone layer 16 , which can further reduce aging damage caused by bending of the pressure sensor module 1 , and can further improve flexibility, thereby increasing the application range of the pressure sensor module 1 .

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model rather than to limit it. Other modifications or equivalent substitutions made to the technical solution of the utility model by ordinary technicians in this field should be included in the scope of the claims of the utility model as long as they do not depart from the spirit and scope of the technical solution of the utility model.

Claims

1. A pressure data acquisition circuit, characterized in that: It includes a pressure sensor module, a first switch module, a second switch module and an MCU module; The pressure sensor module comprises a piezoresistive layer and a first electrode and a second electrode attached to both sides of the piezoresistive layer; a plurality of the first electrodes are arranged in parallel and at equal intervals, a plurality of the second electrodes are arranged in parallel and at equal intervals, and the first electrode and the second electrode are perpendicular to each other; The first electrodes are divided into a plurality of groups according to the position sequence, each group of the first electrodes is equipped with a first switch module, and the first electrodes in each group are electrically connected to the switch ports corresponding to the first switch modules one by one; the second electrodes are divided into a plurality of groups according to the position sequence, each group of the second electrodes is equipped with a second switch module, and the second electrodes in each group are electrically connected to the switch ports corresponding to the second switch modules one by one; The common ports of the first switch modules are electrically connected to the voltage source, and the common ports of the second switch modules are electrically connected to the analog input ports of the MCU module; the controlled ports of the first switch modules and the controlled ports of the second switch modules are electrically connected to the control ports of the MCU module respectively.

2. The pressure data acquisition circuit according to claim 1, characterized in that: The pressure sensor module further includes a first protective layer and a second protective layer, wherein the first protective layer is disposed on the outer side of the first electrode and is bonded to the piezoresistive layer, and the second protective layer is disposed on the outer side of the second electrode and is bonded to the piezoresistive layer.

3. The pressure data acquisition circuit according to claim 2, characterized in that: The outer side of the pressure sensor module is also wrapped with an integral silica gel layer.

4. The pressure data acquisition circuit according to claim 2, characterized in that: The pressure sensor module is provided with vias at the gap between the first electrode and the second electrode along the thickness direction.

5. The pressure data acquisition circuit according to claim 1, characterized in that: It also includes a power module, a storage module and a communication module; the power module is used to provide electrical energy; the storage module is used to store the collected voltage data or pressure data; and the communication module is used to communicate with external devices.

6. The pressure data acquisition circuit according to claim 1, characterized in that: The first electrode and the second electrode are both in a linear or strip shape and have the same width.

7. The pressure data acquisition circuit according to claim 1, characterized in that: The number of the first electrodes in each group is 4-16, and the number of the second electrodes in each group is 4-16.

8. The pressure data acquisition circuit according to claim 1, characterized in that: The first switch module and the second switch module each have 16 switch ports.

9. The pressure data acquisition circuit according to claim 1, characterized in that: The models of the first switch module and the second switch module are both CD74HCx4067.

10. The pressure data acquisition circuit according to claim 1, characterized in that: The number of the first switch modules and the number of the second switch modules are both 4, and the number of electrodes in each group of the first electrodes and the number of electrodes in each group of the second electrodes are both 16.

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