Microbit Connector

Connect a BBC micro:bit v2 from your computer, then send serial/UART commands from the browser. Click the board or use the command panel once connected.

Firmware protocol cheat sheet

Flash micro:bit v2 with a UART listener. Each command is one line ending with a newline (\n).

SMILE — show happy face
LOGO — logo touch event from the connector UI
SAD — show sad face
CLEAR — clear the LED matrix
HEART / YES / NO — built-in icons
BEEP — play a short tone (v2)
PING — optional health check (reply PONG)
BTN_A / BTN_B — button press events from the connector UI
TEXT:<message> — scroll text after the colon
ICON:<name> — named icon (happy, sad, heart, yes, no, surprised, asleep, arrow_up, arrow_down, arrow_left, arrow_right)

MakeCode example:

bluetooth.startUartService()
serial.onDataReceived(serial.delimiters(Delimiters.NewLine), function () {
  let cmd = serial.readUntil(serial.delimiters(Delimiters.NewLine))
  if (cmd == "SMILE") { basic.showIcon(IconNames.Happy) }
  else if (cmd == "LOGO") { basic.showIcon(IconNames.Yes) }
  else if (cmd == "CLEAR") { basic.clearScreen() }
  else if (cmd.substr(0, 5) == "TEXT:") { basic.showString(cmd.substr(5)) }
})

Connect a micro:bit to enable the interactive board

ConnectionDisconnected

Web Bluetooth is not available in this browser.

USB connection requires Chrome or Edge with Web Serial or WebUSB.

Protocol commands

Use the buttons below or click the micro:bit SVG (buttons, display, logo, speaker).

ICON commands

TEXT command payload

Requirements

BBC micro:bit v2 with UART-enabled firmware (MakeCode: bluetooth.startUartService()).
For Bluetooth: enable open BLE on the board and use Chrome/Edge on desktop or Android.
For USB: connect via cable; Chrome/Edge will offer Web Serial (preferred) or WebUSB.
User gesture is required — click Connect and pick the device in the browser dialog.
HTTPS in production (localhost works for development).