147 lines
4.0 KiB
JavaScript
147 lines
4.0 KiB
JavaScript
"use strict";
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const fs = require('mz/fs'),
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exec = require('mz/child_process').exec,
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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 // default 'both'
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this.delay = opts.delay // default = 50
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this.pull = opts.pull // default = pu
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this.puller = opts.puller ? opts.puller : (num, state) => { return `raspi-gpio set ${num} ${state}` } // default rpi using raspi-gpio
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// this.puller = (num, state) => { return `raspi-gpio set ${num} ${state}` }
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this.dbt = opts.debounce ? opts.debounce : 200
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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 {
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// this.clear().then(this.emit('fired', this.hook))
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this.emit('fired', this.hook)
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}
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}, this.dbt, true) // true = leading
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)
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}
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init() {
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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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return _.pSeries([
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this.exit(),
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this._pull(this.num, this.pull),
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this._export(this.num),
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this._direction('in', this.delay),
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() => this._edge(this.edge), // TODO determine why these need additional function
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() => this._fd()
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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).then(() => { return Promise.resolve('interrupt cleared') })
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}
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exit() {
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return new Promise((resolve, reject) => {
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pathExists(this.path)
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.then((exists) => {
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if (exists) {
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fs.writeFile(GPIO_ROOT_PATH + 'unexport', this.num)
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.then(() => {
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if (this.valuefd) {
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this.stop()
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fs.close(this.valuefd)
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}
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this._pull(this.num, 'pn')
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})
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.then(resolve('unexported and exited'))
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} else {
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resolve('already unexported')
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}
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})
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.catch(err => resolve(err))
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})
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}
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start() {
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return this.clear().then(() => this.poller.add(this.valuefd, Epoll.EPOLLPRI | Epoll.EPOLLONESHOT));
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}
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reset() {
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return this.clear().then(() => this.poller.modify(this.valuefd, Epoll.EPOLLPRI | Epoll.EPOLLONESHOT));
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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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/*******private methods*********/
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_pull(num, state = 'pu') {
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if (this.puller === 'external') { return Promise.resolve('pull must be set externally') } else {
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return exec(this.puller(num, state))
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.then(() => { return Promise.resolve(`pull set ${state}`) })
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}
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}
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_fd() {
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return fs.open(this.path + 'value', 'r+')
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.then(fd => {
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this.valuefd = fd
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return Promise.resolve(`value fd set ${fd}`)
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})
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}
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_export(num) {
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return new Promise(function (resolve, reject) {
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fs.writeFile(GPIO_ROOT_PATH + 'export', num)
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.then(() => { return resolve('exported') })
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.catch((err) => { return reject(err) })
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})
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}
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_direction(dir = 'in', delay = 50) {
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return pWaitFor(() => pathExists(this.path + 'direction'))
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.then(_.pDelay(delay))
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.then(() => {
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return fs.writeFile(dir + 'direction', dir)
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.then(() => {
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return Promise.resolve(`direction set ${dir}`)
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})
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})
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}
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_edge(edge = 'both') {
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return fs.writeFile(this.path + 'edge', edge)
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.then(() => {
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return Promise.resolve(`edge set ${edge}`)
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})
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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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