title: node.js serialport, trying to write and I just can't figure it out
body: <p>My knowledge of rs232 is pretty much nothing.  I have an LED display connected to a serial port.  I'm using node.js v8.22 and node-serialport v1.1.0.  </p>
  
  <p>The LED display's user guide is asking for [hex80]xxxxxx[cr] to be sent, where each "x" is a single digit (0-9).  I have the baud rate at 9600 as it dictates as well.  </p>
  
  <p>I'm assuming i could write </p>
  
  <pre><code>sp.write(0x80);
  sp.write('123456\r');
  </code></pre>
  
  <p>But honestly, I just don't know how to translate [hex80]xxxxxx[cr] to javascript/serialport needs.  I've tried various things.</p>
  
  <p>sp.write([0x80,55,55,55,49,49,48,'\r']); // hex80 + all the char codes for the digits
  sp.write(128+'123456\r') // 128 is decimal for 0x80</p>
  
  <p>I have gotten some jumbled stuff to be displayed.  Full code below.</p>
  
  <pre><code>var serialPort, sp;
  
  var comPort = '/dev/cu.usbserial';
  
  var serialPort = require('serialport').SerialPort
  sp = new serialPort(comPort, { baudrate: 9600, parser: parserJaCircuitsChrono() });
  
  sp.on("open", function () {
      console.log(comPort + ' is open');
      sp.write(0x80);
      sp.write('123456\r');
  });
  </code></pre>
  
  <p>Any thoughts or help is greatly appreciated.</p>
  
  <p>Thanks.</p>