uci-i2c-device/src/bus.js

79 lines
2.1 KiB
JavaScript

// Solely a promise wrapper module for the basic async functions of the fivdi/i2c-bus javascript bindings C API
// https://github.com/fivdi/i2c-bus
'use strict'
const i2c = require('i2c-bus'),
Mux = require('/opt/lighting-dev/lib/uci-mux/src/tca9546A'),
pify = require('pify')
class Bus {
constructor(busnum, opts={}) {
// dealing with missing default busnum when options are provided
if (!busnum) { this.busnum = 1 }
else {
if (typeof(busnum) === Number) {
this.busnum = busnum
this.opts = opts
}
this.opts = busnum.opts
}
this.bus = i2c.open(this.busnum, () => {})
this.mux = {} // initialze mux in init method if address provided in options
}
// see https://github.com/fivdi/i2c-bus#busi2cfuncscb for list of functions that can be promisified
scan() { return pify(this.bus.scan).bind(this.bus)() }
close() { return pify(this.bus.close).bind(this.bus)() }
readRaw(address, length, buffer) {
return pify(this.bus.i2cRead).bind(this.bus)(address, length, buffer)
}
writeRaw(address, length, buffer) {
return pify(this.bus.i2cWrite).bind(this.bus)(address, length, buffer)
}
read(address, cmd) {
console.log('read: address, cmd', address, cmd)
return pify(this.bus.readByte).bind(this.bus)(address, cmd)
}
write(address, cmd, byte) {
console.log('write: address, cmd, byte', address, cmd, byte)
return pify(this.bus.writeByte.bind(this.bus))(address, cmd, byte)
}
read2(address, cmd) {
return pify(this.bus.readWord.bind(this.bus))(address, cmd)
}
write2(address, cmd, bytes) {
return pify(this.bus.writeWord.bind(this.bus))(address, cmd, bytes)
}
receive(address) {
return pify(this.bus.receiveByte.bind(this.bus))(address)
}
send(address, byte) {
return pify(this.bus.sendByte.bind(this.bus))(address, byte)
}
async init() {
if (this.opts.muxAddress) {
this.mux = new Mux(this.bus, this.opts.muxAddress, { init: this.opts.muxInit })
return await this.bus.mux.init()
}
}
} // end of Bus Class
module.exports = {
Bus
}