Matrix - IR Counter

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Revision as of 04:15, 21 June 2016 by Yftan (Talk | contribs) (Basic Device Operation)

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1 Introduction

Matrix-IR Counter.png
  • The Matrix IR_Counter uses a U type infrared beam photoelectric sensor. It has a 5 pin 2.54 mm pitch pin-header. Pin V is power supply and Pin G is ground. When there is no presence of an object Pin S outputs high

2 Features

  • GPIO interface
  • PCB dimension(mm): 16 x 24 mm

Matrix-IR Counter PCB.png

  • Pin Description:
Pin Description
S Digital Output
V Supply Voltage 5V
G Ground

3 Basic Device Operation

  • There are a transmitter and a receiver on the two wings of the U type slot separately. When the transmitter emits infrared signals an optic axis will be generated. If an object passes through the U type slot and blocks the optic axis the photoelectric switch will generate signals. When the optic axis is not blocked the receiver will receive infrared signals and the module will output high otherwise the module will output low.

4 Applications

4.1 Connect to NanoPi M1

Refer to the following connection diagram to connect the module to the NanoPi M1:

Connection Details:

Matrix-IR_Counter NanoPi M1
S Pin7
V Pin4
G Pin6

4.2 Connect to NanoPi 2

Refer to the following connection diagram to connect the module to the NanoPi 2:

Connection Details:

Matrix-IR_Counter NanoPi 2
S Pin7
V Pin4
G Pin6

4.3 Connect to NanoPi M2 / NanoPi 2 Fire

Refer to the following connection diagram to connect the module to the NanoPi M2/ NanoPi 2 Fire.

Connection Details:

Matrix-IR_Counter NanoPi M2
S Pin7
V Pin4
G Pin6

4.4 Connect to NanoPC-T2

Refer to the following connection diagram to connect the module to the NanoPC-T2:

Connection Details:

Matrix-IR_Counter NanoPC-T2
S Pin15
V Pin29
G Pin30

5 Compile & Run Test Program

Boot your ARM board with Debian and copy the matrix code:

$ apt-get update && apt-get install git
$ git clone

If your cloning is done successfully a "matrix" directory will be generated.

Compile and install Matrix:

$ cd matrix
$ make && make install

Run test program:

$ matrix-gpio_int

Note: this module is not plug and play therefore before running the module please make sure it is connected to an ARM board.
Here is what you should observe:

Waiting event...
Device[0] value is 1

If there is presence of an object in front of it an event will be triggered.

6 Code Sample

This Matrix code sample can work with all the ARM boards mentioned in this module's wiki. The name of this code sample is "matrix-gpio_int". Here is its source code:

int main(int argc, char ** argv)
    int i, board;
    int retSize = -1;
    char value[ARRAY_SIZE(dev)];
    if ((board = boardInit()) < 0) {
        printf("Fail to init board\n");
        return -1;
    if (argc == 2)
        dev[0].pin = atoi(argv[1]);
    system("modprobe "DRIVER_MODULE);
    signal(SIGINT, intHandler);
    if (board == BOARD_NANOPI_T2)
        dev[0].pin = GPIO_PIN(15);
    printf("Use GPIO_PIN(%d)\n", dev[0].pin);
    if ((devFD =sensorInit(dev, ARRAY_SIZE(dev))) == -1) {
        printf("Fail to init sensor\n");
        goto err;
    printf("Waiting event...\n");
    if ((retSize = sensorRead(devFD, value, ARRAY_SIZE(dev))) == -1) {
        printf("Fail to read sensors\n");
    if (retSize > 0) {
        i = 0;
        for (i=0; i<retSize; i++) {
            printf("Device[%d] value is %d\n", i, value[i]);
    system("rmmod "DRIVER_MODULE);
    return 0;

For more details about this APIs called in this code sample refer to Matrix API reference manual

7 Resources

8 Update Log

8.1 June-21-2016

  • Created English wiki