Step 1 of 5
Connect your board
Power on your Beaver Board — the OLED will show a PIN code. Click Connect in the toolbar, choose Connect via Bluetooth, and select your board. If it's your first time, enter the PIN shown on the screen.
The HC-SR04 ultrasonic sensor is wired to GP16 (TRIG) and GP17 (ECHO) on the board — no extra connections needed.
The HC-SR04 sends an ultrasonic pulse and times how long it takes to bounce back. The board converts that round-trip time into centimetres for you automatically.