Puck.js Connect to Adafruit Feather Board

Glad you got it working! ble_simple_uart will always disconnect BLE - it's just there to have something super simple to use.

If you look at https://www.espruino.com/BLE+UART#receiving-evaluating there are some other examples though. Probably most useful is:

NRF.requestDevice({ filters: [{ id: feather }] }).then(function(device) {
  return require("ble_uart").connect(device);
}).then(function(uart) {
  uart.on('data', function(d) { print("Got:"+JSON.stringify(d)); });
  uart.write("testing!"); // .then(...)
  setTimeout(function() {
    uart.disconnect();
    console.log("Disconnected");
  }, 20000); // disconnect after 20s
});