80 lines
2.5 KiB
JavaScript
80 lines
2.5 KiB
JavaScript
'use strict'
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// Creates an ES6 Interrupt class wrapper using the pigio C library and pigpio javascript wrapper package
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// The pigipio C library is specifically coded for the Raspberry Pi but might be adapatable to any single board computer (sbc) with Gpios
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// assuming they would be pigio C, compatiable.
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// Must have pigpio C library installed first.
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// On interrupt emits "fired" which can be caught by the code calling this interrupt instance for handling
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// Understand there are two interrupts here. One is this class and one on the sbc/rpi via pigpio
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// The sbc/pigpio interrupt emits an event which is listened for by this class which then emits
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// a "fired" event which can be can be listed to by having a handle to an instance this class.
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const
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pigpio = require('pigpio'),
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sbcGpio = pigpio.Gpio,
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EventEmitter = require('events')
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class Interrupt extends EventEmitter {
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constructor(pin_number, handler, opts = {}) {
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super()
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this.pin_number = pin_number
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this.handler = handler
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this.mode = sbcGpio.INPUT
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this.pull = opts.pull ? opts.pull : sbcGpio.PUD_DOWN
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this.edge = opts.edge ? opts.edge : sbcGpio.RISING_EDGE
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this.sbc_interrupt = new sbcGpio(
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this.pin_number, {
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mode: this.mode,
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pullUpDown: this.pull,
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// do not! set edge here as it will start the emitter -- see pigio js
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}
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)
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}
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// init() {
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//
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// // console.log(`initialize interrupt ${this.pin_number}`)
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// return Promise.resolve()
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//
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// }
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get pin() {
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return this.pin_number
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}
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async start() {
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console.log(`starting interrupt on pin ${ this.pin_number}`)
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// for cntrl-c exit of interrupt
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process.on('SIGINT', () => {
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this.exit().then((resp) => console.log('\n', resp)) // unexport on cntrl-c
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.catch(err => console.log('error:', err))
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})
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let interrupt = this // scope `this` for use in the listener for each interrupt
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// console.log(`interrupt listener set for rpi ${interrupt.pin_number}`)
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this.sbc_interrupt.on('interrupt', function () {
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// console.log(`the sbc interrupt tripped by sbc pin ${interrupt.pin_number}`)
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interrupt.emit('fired') // emit an event that can be listened for by the device that created the interrupt instance
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})
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// rock n roll!!, start the pigpio interrupt
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this.sbc_interrupt.enableInterrupt(this.edge)
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}
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// manual firing for testing
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fire() {
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let interrupt = this
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console.log('manually firing interrupt', this.handler)
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this.emit('fired')
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}
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exit() {
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pigpio.terminate()
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return Promise.reject(`keyboard termination...terminating interrupt on pin ${this.pin_number}`)
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}
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}
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module.exports = Interrupt
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