STM32 Motor Control with L289N & L293D

Project Description:

This project demonstrates how to control DC motors using L289N and L293D motor driver ICs with the STM32F103C6 microcontroller.

• The setup integrates advanced control techniques including:
• Timers & PWM – for speed regulation
• ADC – to read a potentiometer for analog speed control
• UART – for real-time monitoring and debugging
• Button inputs – for motor direction and mode selection

Motor Driver ICs

• L289N: Dual H-bridge driver, controls 2 DC motors or 1 stepper motor, up to 1A/channel, requires external control logic, works at 4.5V–36V.
• L293D: Dual H-bridge driver, controls 2 DC motors or 1 stepper motor, up to 600mA/channel, has built-in control logic and internal voltage regulator, operates at 4.5V–36V.

Circuit Overview

• L298N Control – Dual H-Bridge motor driver interface
• L293D Control – Bidirectional motor driver interface
• ADC – Read analog sensor values
• TIM2 (PWM) – Generate pulse width modulation signals
• UART1 – Serial communication for data exchange

STM32CubeMX Setup

• Target MCU: STM32F103C6Tx
• Clock Configuration: System clock = 8 MHz
• GPIO:

- PA6 → Mode Selector (L289N/L293D)

- PB6–PB11 → Control buttons

- PB14, PB15, PA3 → L289N control

- PB12, PB13, PA2 → L293D control

• TIM2 PWM Setup:

- Enable TIM2

- Channels: Enable PWM on CH3 and CH4

- Prescaler = 800

- Period = 1000

- Pulse = 500 (adjustable for speed)

• ADC1:

- Enable IN9 (Potentiometer input)

- Mode: Continuous Conversion

• USART1:

- Baud Rate = 9600

- Mode = Asynchronous

- Word Length = 8 Bits

- Stop Bits = 1

- Parity = None

• Generate code and open in STM32CubeIDE.

STM32CubeIDE Implementation

• Initialize all peripherals: GPIO, ADC, TIM2 (PWM), UART.
• Start ADC conversion and PWM outputs.
• Implement logic:

- ADC: Read potentiometer → map value to PWM duty cycle.

- PWM: Adjust motor speed (0–100%).

- Buttons: Change motor direction (CW/CCW), enable/disable motors, select fixed speeds (25%, 50%, 75%).

- UART: Send live feedback of ADC values and motor status.

Proteus Simulation

• Create a new project.
• Add components:

- STM32F103C6 MCU

- L289N driver

- L293D driver

- DC Motors

- Potentiometer (ADC input)

- Control Buttons (SPDT switches)

- Power supply (VCC, GND)

- Virtual Terminal (UART debug)

- Oscilloscope (optional for PWM analysis)

• Wire connections according to CubeMX configuration.
• Load the compiled .hex firmware into the STM32 MCU.
• Run the simulation and observe:

- Motor speed changes with potentiometer.

- Direction changes with button press.

- UART logs motor status in Virtual Terminal.

That's all!

If you have any questions or suggestions don't hesitate to leave a comment below