homebridge-433-arduino/tc-serial.js

Add bidirectional support for 433MHz switches to Homebridge using Arduino or ESP hardware.

const SerialPort = require('serialport');
const Readline = SerialPort.parsers.Readline;

function SerialTransceiver (log, portName, ioTimeout = 500) {
  this.log = log;
  this.portName = portName;
  this.ioTimeout = ioTimeout;
  this.blockPort = null;
  this.inPort = null;
}

SerialTransceiver.prototype.setCallback = function (callback) {
  this.callback = callback;
};

SerialTransceiver.prototype.init = function () {
  this.port = new SerialPort(this.portName, { baudRate: 9600 });
  this.inPort = this.port.pipe(new Readline({ delimiter: '\n' }));
  this.blockPort = new Device(this.port, this.ioTimeout);
  this.inPort.on('data', this.serialCallback.bind(this));
};

SerialTransceiver.prototype.send = function (message) {
  if (message.code) {
    this.blockPort.send(message.code + '/' + message.pulse + '/' + message.protocol + '\n');
  } else if (message.type && message.message) {
    try {
      this.blockPort.send(JSON.stringify(message) + '\n');
    } catch (e) { this.log(e); }
  }
};

SerialTransceiver.prototype.serialCallback = function (data) {
  if (data.startsWith('OK')) return;
  this.blockPort.lastInputTime = new Date().getTime();
  if (data.startsWith('{')) {
    try {
      const message = JSON.parse(data);
      this.callback(message);
    } catch (e) { this.log(e); }
    return;
  }
  if (data.startsWith('pilight')) {
    this.log(data);
    return;
  }
  var content = data.split('/');
  if (content.length >= 2) {
    var value = content[0];
    var pulse = content[1].replace('\n', '').replace('\r', '');
    var protocol = content[2];
    if (protocol) {
      protocol = protocol.replace('\n', '').replace('\r', '');
    } else {
      protocol = 1;
    }
    this.callback({ code: Number(value), pulse: Number(pulse), protocol: Number(protocol) });
  }
};

/* private class device, send to serial port with queue */
function Device (serial, ioTimeout = 500) {
  this.lastInputTime = 0;
  this.ioTimeout = ioTimeout;
  this._serial = serial;
  this._queue = [];
  this._busy = false;
  var device = this;
  var pipedSerial = serial.pipe(new Readline({ delimiter: '\n' }));
  pipedSerial.on('data', function (data) {
    if (data.startsWith('OK')) {
      device.processQueue();
    }
  });
}
Device.prototype.send = function (data) {
  this._queue.push(data);
  if (this._busy) return;
  this._busy = true;
  this.processQueue();
};
Device.prototype.processQueue = function (inData) {
  var next = inData === undefined ? this._queue.shift() : inData;
  if (!next) {
    this._busy = false;
    return;
  }
  var curTime = new Date().getTime();
  if (curTime - this.lastInputTime < this.ioTimeout) {
    setTimeout(this.processQueue.bind(this, next), this.ioTimeout);
  } else {
    this._serial.write(next);
  }
};

module.exports = SerialTransceiver;