Micro:bit robot controlled by joystick

Tutorial plan

1- Operation of Micro:bit robot controlled by joystick

2- Components of the robot

3- Mounting of the robot

4- Programming the Micro:bit board with Makecode

Operation of Micro:bit robot controlled by joystick

The operation of the Micro:bit robot involves two Micro:bit boards communicating wirelessly to enable joystick-based control of a two-wheeled car kit. Below is a detailed description of the operation:

1- Controller Micro:bit (Transmitter):

A joystick module is connected to the Micro:bit's GPIO pins to capture user input.

The joystick's position (X and Y axes) is read as analog signals, converted into directional commands, and transmitted via the Micro:bit's built-in radio module.

2- Robot Micro:bit (Receiver):

a) Receives the directional commands sent by the transmitter.

b) Controls the two-wheel car kit's motors using relay modules connected to the Micro:bit GPIO pins.

c) Executes forward, left, right, and stop commands based on the received signals.

Components of the robot

1- Joystick (Controller):

X-axis: Controls left-right movement.

Y-axis: Controls forward-backward movement.

Analog outputs of the joystick are connected to Micro:bit's pins (e.g., P1 for X and P2 for Y).

2- Microbits:

Both Micro:bits use the same radio channel to send and receive commands.

The transmitter sends directional commands ("FORWARD", "BACKWARD", "LEFT", "RIGHT", "STOP").

3- Relay Modules:

Each relay module controls one motor.

The relays switch the motors on/off based on the Micro:bit's digital output pins (e.g., P8 and P12).

Two-Wheel Car Kit:

Motors drive the left and right wheels.

Motor speed and direction are indirectly controlled by the relay states.

Power Supply:

Provide a suitable power supply for the robot.

Mounting the joystick with Micro:bit

We connect:

The +5V pin of the 3.3V joystick of the micro:bit

The GND pin of the joystick to the GND of the micro:bit

The VRx pin of the joystick to the pin P2 of the micro:bit

VRy pin from joystick to pin P1 from micro:bit

Pin SW from joystick to pin P0 from micro:bit

Mounting of the robot

To make the robot assembling, we connect :

1- For the first relay:

pin S to pin P0 of the Micro:bit board

the pin (+) to pin 3.3V of the Micro:bit board

the pin (-) to the GND of the Micro:bit board

the pin ON to an energy of 5V

2- For the second relay:

pin S to pin P1 of the Micro:bit board

pin (+) to pin 3.3V of the Micro:bit board

pin (-) to the GND of the Micro:bit board

pin ON to an energy of 5V

3- For each of the two motors:

the first terminal to the COM pin of the relay

the second terminal to the GND terminal of the Micro:bit board

Programming the Micro:bit board with Makecode

1- Transmitter Code (Controller Micro:bit)

The joystick's position is read as analog values, converted into directional commands, and sent via radio.

a) Based on the joystick's position:

Forward: Joystick pushed up.

Left: Joystick pushed left.

Right: Joystick pushed right.

Stop: Joystick centered.

b) The corresponding direction is sent as a string (e.g., "FORWARD") via radio.

Receiver Code (Robot Micro:bit)

The receiver interprets the direction commands and controls the relay modules accordingly.

3- Steps to Test and Operate

a) Assemble the robot with the motor and relay connections.

b) Ensure the joystick is correctly connected to the controller Micro:bit.

c) Upload the transmitter code to the controller Micro:bit.

d) Upload the receiver code to the robot Micro:bit.

e) Power on both Micro:bits and test the joystick controls.