I wrote this little Processing application I’d thought I’d share with you.

It opens a little window with a black circle in it. When you press a key - any key - whatever you press gets sent to your serial port. Also, the circle turns white just to let you know your program is live.

The Processing code that really does anything is just this:

In setup():

String[] ports = Serial.list();
serial = new Serial(this, ports[ports.length-1], baudRate);

and then in keyReleased():

serial.write(key);

That’s it. Very handy.

Download the sendkeys processing code