92 lines
2.5 KiB
JavaScript
92 lines
2.5 KiB
JavaScript
"use strict";
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const fs = require('mz/fs'),
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EventEmitter = require('events'),
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Epoll = require('epoll').Epoll,
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_ = require('uci-utils')
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const pWaitFor = require('p-wait-for')
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const pathExists = require('path-exists');
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const debounce = require('debounce');
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const GPIO_ROOT_PATH = '/sys/class/gpio/'
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class Interrupt extends EventEmitter {
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// bus is i2c-bus bus object
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constructor(pin_number, opts = {}) {
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super()
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this.num = pin_number;
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this.hook = opts.hook // will be passed back with the emit
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this.path = GPIO_ROOT_PATH + 'gpio' + this.num + '/'
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this.edge = opts.edge ? opts.edge : 'falling'
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this.delay = opts.delay ? opts.delay : 50
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this.dbt = opts.debounce ? opts.debounce : 300
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this.poller = new Epoll(
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debounce((err, fd, events) => {
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if (err) { this.emit('error', err) } else { this.clear().then(this.emit('fired', this.hook)) }
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}, this.dbt, true)
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)
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}
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init() {
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let tasks = [
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() => { return fs.writeFile(GPIO_ROOT_PATH + 'export', this.num).then(() => { console.log('exported') }) },
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() => {
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return pWaitFor(() => pathExists(this.path + 'direction')).then(_.pDelay(this.delay))
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.then(() => { return fs.writeFile(this.path + 'direction', 'in').then(() => { console.log('direction set') }) })
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},
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() => { return fs.writeFile(this.path + 'edge', this.edge).then(() => { console.log('edge') }) },
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() => { return fs.open(this.path + 'value', 'r+').then(fd => { this.valuefd = fd }) },
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() => { return this.clear().then(() => { return this.start() }) }
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]
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process.on('SIGINT', () => {
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this.exit().then(() => console.log('\nunexported and closed')) // unexport on cntrl-c
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})
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return this.exit() // make sure pin is unexported
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.then((resp) => {
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console.log(resp)
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return _.pSeries(tasks)
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})
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}
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fire(name = 'fired') {
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this.emit(name, this.hook)
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}
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clear() {
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let buffer = Buffer.from([0x00])
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return fs.read(this.valuefd, buffer, 0, 1, 0);
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}
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exit() {
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return pathExists(this.path)
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.then(() => {
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return fs.writeFile(GPIO_ROOT_PATH + 'unexport', this.num)
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})
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.then(() => {
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if (this.valuefd) {
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this.stop()
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return fs.close(this.valuefd)
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}
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})
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.catch(err => { return Promise.resolve('already unexported') })
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}
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start() {
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this.poller.add(this.valuefd, Epoll.EPOLLPRI);
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}
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stop() {
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this.poller.remove(this.valuefd).close();
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}
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}
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module.exports = {
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Interrupt
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}
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