Difference between revisions of "Matrix - One Touch Sensor"

Revision as of 23:43, 21 June 2016

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1 Introduction

• The Matrix One_Touch_Sensor is a digital one capacitive touch key module. It uses the one key capacitive touch pad detector IC TTP223. It has a touch key with stable touching detection. It is designed for replacing traditional direct button key with diverse pad size.By default it outputs low. When a finger touches the touch key it outputs high.

2 Features

• Standard 3Pin interface
• PCB dimension(mm): 16 x 24

• Pin Description:

3 Basic Device Operation

TTP223是一颗单键电容式触摸检测IC,它是利用电荷转移技术，通过检测压克力、塑料、玻璃、陶瓷、木材等绝缘介质上的按键电极与地的寄生电容电荷的微小改变来进行检测。

4 Applications

4.1 Connect to NanoPi M1

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

Connection Details:

4.2 Connect to NanoPi 2

Refer to the following connection diagram to connect the module to the NanoPi 2:
Matrix-One_Touch_Sensor_nanopi_2

Connection Details:

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:

4.4 Connect to NanoPC-T2

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

Connection Details:

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 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 touch the module's active area an event will be triggered and detected.

6 代码说明

所有的开发板都共用一套Matrix代码，本模块的测试示例代码为matrix-gpio_int，内容如下:

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]);
        }
    }
    sensorDeinit(devFD);
err:    
    system("rmmod "DRIVER_MODULE);
    return 0;
}

API说明参考维基：Matrix API reference manual

7 Resources