Best way to send Javscript code with own Android app.

Take a look at http://www.espruino.com/About+Bluetooth+LE

You basically want to get the characteristic "6e400002-b5a3-f393-e0a9-e50e24dcca9e" on the service "6e400001-b5a3-f393-e0a9-e50e24dcca9e" and then write to it repeatedly with blocks of 20 characters or less.

You basically just send the raw JavaScript code, although it's going in as if you typed it, so you need to be careful to put open brackets before newlines:

// good
function hello() {
  // stuff
}
// bad
function hello()
{
  // stuff
}

In fact, Nordic provide the source code to their apps - including the Nordic UART, so it should be pretty easy to get something working by copying their code.

• App: https://github.com/NordicSemiconductor/Android-nRF-UART
  
• Actual UART source code: https://github.com/NordicSemiconductor/Android-nRF-UART/blob/master/app/src/main/java/com/nordicsemi/nrfUARTv2/UartService.java