Puck.js Connect to Adafruit Feather Board

On the Puck, maybe try:

function sendMessage() {
  console.log("Trying to Connect");
  NRF.requestDevice({ filters: [{ id: feather }], active:true }).then(function(device) {
  return require("ble_uart").connect(device);
}).then(function(_uart) {
  uart = _uart;
  uart.on('data', function(d) {
    console.log("Got:"+JSON.stringify(d));
  });
  return uart.write("1");
}).then(function() {
  console.log("Message sent successfully.");  
});
}

There were a few issues on the Puck side:

• you weren't returning the promise from uart.write so it'd have returned immediately
  
• best to register to receive the data before it's sent, or maybe the data will come back before the .on has executed
  
• You were never setting the value of the global uart variable - it would always have been undefined, so the uart.on code would always fail