rn-42

Yeah, that's a tricky one. I'd maybe just do:

exports.initialise = function(descriptor_callback, send_hid_callback) { 
 ...
}

Then you can do:

function send_hid_callback(data) {
Serial.write(
    0xFD,                // indicates raw hid report
    0x06,                 // bLength
    0x01,                 // bDescriptorType - constant ( String assigned by USB )
    data
);
}

for the RN-42?