Matrix - Button

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Introduction

Button
  • The Matrix-Button module is used to detect button events.
  • If the button is not pressed S will output high otherwise S will output low.

Features

  • 3 PIN interface
  • PCB dimension (mm): 8 x 24

BTN-01.PCB

  • Pin Description:
Pin Description
S GPIO
V Supply Voltage 5V
G Ground

Basic Device Operation

  • The Matrix-Button is an instant(non self-lock) button. The button's status can be read from pin S in the 3-pin 2.54 mm spacing pin header.
  • If the button is not pressed S will output high otherwise S will output low.

Applications

Connect to NanoPi M1

Refer to the following connection diagram to connect the module to the NanoPi M1:
Matrix-Button_nanopi_m1

Connection Details:

Matrix-Button NanoPi M1
S Pin7
V Pin4
G Pin6

Connect to NanoPi 2

Refer to the following connection diagram to connect the module to the NanoPi 2:
Matrix-Button_nanopi_2

Connection Details:

Matrix-Button NanoPi 2
S Pin7
V Pin4
G Pin6

Connect to NanoPi M2 / NanoPi 2 Fire

Refer to the following connection diagram to connect the module to the NanoPi M2/ NanoPi 2 Fire:
Matrix-Button_nanopi_m2

Connection Details:

Matrix-Button NanoPi M2
S Pin7
V Pin4
G Pin6

Connect to NanoPC-T2

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

Connection Details:

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

Compile & Run Test Program

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

$ apt-get update && apt-get install git
$ git clone https://github.com/friendlyarm/matrix.git

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

When you press the button an event will be detected.

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");
 
    if (argc == 2) {
        dev[0].pin = atoi(argv[1]);
    }
    printf("Using GPIO_PIN(%d)\n", dev[0].pin);
    system("modprobe "DRIVER_MODULE);
    signal(SIGINT, intHandler);
    if (board == BOARD_NANOPI_T2)
        dev[0].pin = GPIO_PIN(15);
    if ((devFD =sensorInit(dev, ARRAY_SIZE(dev))) == -1) {
        printf("Fail to init sensor\n");
        return -1;
    }
    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("dev[%d] value: %d\n", i, value[i]);
        }
    }
    sensorDeinit(devFD);
    system("rmmod "DRIVER_MODULE);
    return 0;
}

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


Resources

Update Log

Feb-19-2016

  • In section 4 added NanoPi 2 branch
  • In section 5.2 added the driver and its source code's locations

June-17-2016

  • Re-organized and simplified wiki