Read P1 port

p1.js

/**
 * Starts serial port reader. Retries via {@link tryInitP1} when port is
 * disconnected or on error.
 *
 * @function tryInitP1
 * @param {function} messageHandler What to do with the message
 * @returns {undefined}
 */
function initP1(messageHandler) {
  logger.info(`Initializing P1 reader on serial port ${RASPBERRY_PI_USB_PORT}`);

  const TELEGRAM_SEPARATOR = '!';
  const serialPort = new SerialPort(RASPBERRY_PI_USB_PORT, {
    ...p1Config,
    parser: SerialPort.parsers.readline(TELEGRAM_SEPARATOR),
  });

  serialPort.on('data', telegram => messageHandler(telegram));

  serialPort.on('error', (err) => {
    logger.error(`Error when reading port ${err}`);
    tryInitP1(messageHandler);
  });

  serialPort.on('close', () => {
    logger.info('Port closed');
    tryInitP1(messageHandler);
  });
}