uci-i2c-bus/src/device.js

77 lines
2.1 KiB
JavaScript

'use strict'
// **********************************
class Device {
// bus is i2c-bus bus object
constructor(bus, address, opts) {
this.bus = bus
this.address = address
if (opts) {
this.id = opts.id // must be unique within a bus
this.desc = opts.desc
this.channel = opts.channel // if using TAC9546A channel number on which device is attached
}
}
async _setChannel() {
// console.log('before set',this.address,this.id,this.channel, this.bus.getState)
if (this.channel) {
if (!this.bus.address) { return Promise.reject('Channel set but no mux on bus')}
return this.bus.set(this.channel)
}
return Promise.resolve() // no channel for device either no mux or device is attached to mux bypass
}
// for devices that need just a simple send of a byte without a register command
async receive() {
await this._setChannel()
return this.bus.receive(this.address)
}
async send(cmd, byte) {
await this._setChannel()
return this.bus.send(this.address, cmd, byte)
}
// for devices needing a buffer/stream
async readRaw(length, buffer) {
await this._setChannel()
return this.bus.readRaw(this.address, length, buffer)
}
async writeRaw(length, buffer) {
await this._setChannel()
return this.bus.writeRaw(this.address, length, buffer)
}
// both cmd and byte should be a single byte as a decimal or hex
async read(cmd) {
await this._setChannel()
// console.log('after set before read',this.address,this.id,this.channel,this.bus.getState)
return this.bus.read(this.address, cmd)
}
async write(cmd, byte) {
await this._setChannel()
// console.log('after set, before write',this.address,this.id,this.channel,this.bus.getState)
return this.bus.write(this.address, cmd, byte)
}
// for I2C devices that use a word length packackage
async read2(cmd) {
await this._setChannel()
return this.bus.read2(this.address, cmd)
}
async write2(cmd, bytes) {
await this._setChannel()
return this.bus.write2(this.address, cmd, bytes)
}
}
module.exports = {
Device
}