FunduMotoJoystick

FunduMoto L298P shield motor driver for Nucleo F446RE board. Based on HAL.

FunduMoto communicates with the client app via Bluetooth UART4 with Periph-to-memory RX DMA (circular mode, RingBuffer).

👉 For autonomous robot navigation, switch to nn branch.

Pinout

OnBoard	Pinout	TIM/UART	Specs
Motor A	D12 (PA6) direction, D10 (PB6) speed	TIM4_CH1	90 MHz / (100 * 45,000) = 20 Hz
Motor B	D13 (PA5) direction, D11 (PA7) speed	TIM14_CH1	90 MHz / (100 * 45,000) = 20 Hz
Servo	D9 (PC7)	TIM3_CH2	90 MHz / (90 * 20,000) = 50 Hz
Sonar HC-SR04	D7 (PA8) Trig, D8 (PA9) Echo	TIM1_CH1	180 MHz / (360 * 50,000) = 10 Hz
Bluetooth HC-05	RX -> PC10 (TX), TX -> PC11 (RX)	UART4	9600 Bits/s

Initialization

Here is how FunduMoto_Init() looks like:

HAL_TIM_PWM_Start_IT(&htim4, TIM_CHANNEL_1);  // motorA (handles interrupts for both motors)
HAL_TIM_PWM_Start(&htim14, TIM_CHANNEL_1);    // motorB
HAL_TIM_PWM_Start_IT(&htim3, TIM_CHANNEL_2);  // servo
HAL_TIM_PWM_Start(&htim1, TIM_CHANNEL_1);     // sonar

Usage

// ... CubeMX initialization of HAL, timers, etc.
FunduMoto_Init();

while (1) {
	FunduMoto_ReadUART();
	FunduMoto_Update();
}

FunduMoto_ReadUART() pulls, parses, and evaluates received Bluetooth commands.

FunduMoto_Update() filters and sends sonar distance, read at interrupts.

Bluetooth RX commands

You can also use Bluetooth terminal to receive commands.

• Motor M<angle:4d>,<velocity:.2f>: set vehicle's velocity amplitude and angle for the next FunduMoto_MotorCycles cycles (25 ms).
• Servo S<angle:3d>: set servo angle.
• Buzzer B<state:1d>: on/off buzzer.
• Dist D<dist:3d>: set sonar max dist in cm (default is 400 cm).
• Tolerance T<tol:1d>: set sonar tolerance in cm (default is 1 cm).
• Filter F<size:1d>: set sonar median filter size (default is 3).

Difference with Arduino pinout connection

FunduMoto schield connects Bluetooth to D1 and D0, which are used by USART2 debugger, embedded in Nucleo board. Instead, I connect Bluetooth to PC10 and PC11.

Possible issues

1. Wrong motor(s) direction. Just switch '+' and '-' pins.
2. Sonar does not work realiably. Onboard yellow connector pins wiring is weak and you might loose the connection with the sonar when servo rotates and pulls the wire. Better to connect Trig and Echo pins directly to D7 and D8 pins.