stecman

Controlling the Brother P-Touch Cube label maker from a computer

The Brother PTP300BT label maker is intended to be controlled using the official Brother P-Touch Design & Print iOS/Android app. The app has arbitrary limits on what you can print (1 text object and up to 3 preset icons), so I thought it would be a fun challenge to reverse engineer the protocol to print whatever I wanted.

Python code at the bottom if you want to skip the fine details.

Process

Intitially I had a quick peek at the Android APK to see if there was any useful information inside. The code that handles the communication with the printer in Print&Design turned out to be a native library, but the app clearly prepares a bitmap image and passes it to this native library for printing. Bitmaps are definitely something we can work with.

electricimp

server.log("Device Started");

function arduinoData() 
{
    // Read the UART for data sent by Arduino to indicate
    // the state of its LED.
    
    local b = arduino.read();
    while(b != -1) 
    {

mrdoob

/**
 * Provides requestAnimationFrame in a cross browser way.
 * @author paulirish / http://paulirish.com/
 */

if ( !window.requestAnimationFrame ) {

	window.requestAnimationFrame = ( function() {

		return window.webkitRequestAnimationFrame ||