// slave
var rs485 = require('@amperka/rs-485').connect({
  serial: Serial3,
  speed: 115200,
  dirPin: P3,
  lineEnding: '\n'
});
  
var buf = "";
var line = "";
rs485.on('data', function(data) {
  buf += data;
  var idx = buf.indexOf("\n");
  while (idx >= 0) {
    line = buf.substr(0, idx);
    buf = buf.substr(idx + 1);
    idx = buf.indexOf("\n");
  }
  let device = JSON.parse(line);
  print("Devive #" + device.id);
  print(" - Value " + device.value);
});