pigpio/test/isr-multiple-sources.js

Fast GPIO, PWM, servo control, state change notification, and interrupt handling on the Raspberry Pi

'use strict';

// For this test to work
// - GPIO7 needs to be connected to GPIO8 with a 1K resistor
// - GPIO9 needs to be connected to GPIO11 with a 1K resistor

const Gpio = require('../').Gpio;

[[7, 8], [9, 11]].forEach((gpioNos) => {
  const input = new Gpio(gpioNos[0], {mode: Gpio.INPUT, edge: Gpio.EITHER_EDGE});
  const output = new Gpio(gpioNos[1], {mode: Gpio.OUTPUT});

  let interruptCount= 0;

  // Put input and output in a known state
  output.digitalWrite(0);

  // Interrupts rely on sysfs files in directory /sys/class/gpio.
  // Wait till these sysfs files are fully initialized before proceeding.
  setTimeout(() => {
    // Read input to clear any potential initial unauthentic interrupt
    input.digitalRead();

    input.on('interrupt', (level) => {
      interruptCount += 1;
      output.digitalWrite(level ^ 1);

      if (interruptCount === 1000) {
        console.log('  ' + interruptCount + ' interrupts detected on GPIO' + gpioNos[0]);
        input.disableInterrupt();
      }
    });

    setTimeout(() => {
      // Trigger first interrupt
      output.digitalWrite(1);
    }, 2);
  }, 10);
});