microbit-webble.js

A javascript library to interact with BBC micro:bit using web bluetooth API.

Usage

To use the library, download and upload this firmware on your BBC micro:bit board.

Keep in mind that web bluetooth API are still experimental and your OS and browser might not support the feature. Read more about this here.

Please refer to the following table for the supported browsers.

Browser	WebUSB	WebBluetooth
Chrome (Win/Mac) / Edge	○	○
Safari	×	×
Firefox	×	×
Opera	○	○
Chrome on Android	○	○
Safari on iOS	×	×
Chromium on Raspberry PI	_	_

This Library allows you to read and write the values of all the BLEcharacteristic exposed by the microBit board using simplified API's.

For more info about all micro:bit ble services please refer to the official documentation.

The example folder provided contains several examples for interacting with the device.

Constructor

• microBit=new uBitWebBluetooth()

Properties

• microBit.connected

Functions

• microBit.searchDevice() or microBit.connectDevice()

  Search for ble devices in range. 　
  
  example:

  connectButton = createButton("connect");
  connectButton.mousePressed(
    function(){
      microBit.searchDevice();
    }
  );

• microBit.setButtonACallback(callbackFunction)

  Register a callback function to be invoked when Button A is pressed.

  example:

  microBit.setButtonACallback(
    function(){
      console.log("buttonA pressed");
    }
  );

• microBit.setButtonBCallback(callbackFunction)

  Register a callback function to be invoked when Button B is pressed.

  example:

  microBit.setButtonBCallback(
    function(){
      console.log("buttonB pressed");
    }
  );

• microBit.onConnect(callbackFunction)

  Register a callback function invoked when the microBit connects

  example:

  microBit.onConnect(
    function(){
      console.log("connected");
    }
  );

• microBit.onDisconnect(callbackFunction)

  Register a callback function invoked when the microBit disconnects

  example:

  microBit.onDisconnect(
    function(){
      console.log("disconnected");
    }
  );

• microBit.onBleNotify(callbackFunction)

  Register a callback function invoked every time the value of characteristic changes and it is notified by the device.

  example:

  microBit.onBleNotify(
    function(){
      document.getElementById("buttonA").innerHTML=microBit.getButtonA();
    }
  );

• microBit.setReceiveUARTCallback(callbackFunction)

• microBit.onReceiveUART(callbackFunction)

• microBit.onReceiveSerial(callbackFunction)

  Register a callback function to be invoked when UART data is received.

  example:

  microBit.setReceiveUARTCallback(
    function(data){
      console.log("UART received",data);
      receivedText = data;
    }
  );

• microBit.writeUARTData(string)

  Send text message to microbit via UART.

  example:

  var messageText = "Hello!";
  microBit.writeUARTData(messageText);

• microBit.sendSerial(string)

  Send text line to microbit via UART. an alias of writeUARTData()

  example:

  var messageText = "Hello!";
  microBit.sendSerial(messageText);

• microBit.writeMatrixIcon(icon)

  Updates the led matrix on the microbit. The icon passed to the function must be 5x5 matrix. 0=led off; 1=led on;

  example:

  var ledMatrix = [
    ['0', '0', '0', '0', '0'],
    ['0', '1', '0', '1', '0'],
    ['0', '0', '0', '0', '0'],
    ['1', '0', '0', '0', '1'],
    ['0', '1', '1', '1', '0']
  ]
  
  microBit.writeMatrixIcon(ledMatrix);

• microBit.writeMatrixText(text)

  Updates the led matrix of the microbit with a scrolling text.

  example:

  microBit.writeMatrixText("ciao microBit")

• writeMatrixTextSpeed(speed)

  set the speed of the scrolling text on the matrix example:

  microBit.writeMatrixTextSpeed(10)

• microBit.getAccelerometer()

  Returns the value of the accelerometer as a object.

  example:

  acceleration=microBit.getAccelerometer();
  acc_x=acceleration.x;
  acc_y=acceleration.y;
  acc_z=acceleration.z;

• microBit.getTemperature()

  Returns the value of the temperature measured on the processor in celsius.

  example:

  temperature=microBit.getTemperature();

• microBit.getBearing()

  Returns the value of magnetometer bearing from 0 to 360. 0= pointing nord

  example:

  bearing=microBit.getBearing();

Examples

Check the examples folder for working examples.

Basic example

Connect your microbit to a webpage, visualize the data and change the animations on the led matrix.

micro:bit code

Try it here

Accelerometer Cube example

Learn how to interact with the microbit from a p5.js sketch, rotate a cube on the canva reading the accelerometer.

micro:bit code

Try it here

Lars the iceberg

Use the microBit to control Lars the iceberg. Don't let it melt! Developed using p5.js and p5.play library.

micro:bit code

Try it here

UART Echo example

Learn how to exchange text messages between the microbit and a p5.js sketch via UART, update microBit's LED message from the sketch.

micro:bit code

Try it here

UART LightSensor example

Learn how to receive lightsensor value from the microbit and update a p5.js sketch via UART.

micro:bit code for micro:bit v2

micro:bit code for micro:bit v1

Try it here