Matrix - Button

From FriendlyELEC WiKi
Revision as of 06:57, 8 August 2015 by Yonganch (Talk | contribs) (Introduction)

Jump to: navigation, search

查看中文

1 Introduction

按键

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.

2 Features

  • Instant, non self-lock
  • Tiny, easy to be used in various situations
  • 2.54mm spacing pin

3 How To

3.1 Connection

  • Connect to Tiny4412 SDK (1506)
Connect the module's pin S to GPIO PIN1, pin V to 5V and pin G grounded

3.2 Code Sample in C Under Linux

#include <stdio.h>
#include "libfahw.h"
 
static struct sensor button[] = {
        {
                TINY4412_GPIO_PIN1,
                IRQ_TYPE_EDGE_FALLING,
        }
};
 
int main(void)
{
    int i;
    int retSize = -1;
    char value[ARRAY_SIZE(button)];
    int devFD = -1;
    if ((devFD =sensorInit(button, ARRAY_SIZE(button))) == -1) {
        printf("Fail to init sensor\n");
        return -1;
    }
    printf("Press the button...\n");
    if (( retSize = sensorRead(devFD, value, ARRAY_SIZE(button)) ) == -1) {
        printf("Fail to read sensors\n");
    }
    if (retSize > 0) {
        i = 0;
        for (i=0; i<retSize; i++) {
            printf("Button[%d]:%d\n", i, value[i]);
        }
    }
    sensorDeinit(devFD);
    return 0;
}

3.3 Compile and Run

git clone http://github.com/friendlyarm/fa-hardware.git
cd fa-hardware
cd demo
cd matrix-button
make

Copy your compiled bin to your board and you are ready to go.

4 Resources