1. A smartphone-controlled DC motor system that varies speed wirelessly over Bluetooth. The phone sends commands to a microcontroller, which generates PWM signals to a motor driver. You can increase/decrease speed, start/stop, and change direction (optional) from within an app. Features like soft start, speed ramping, and overcurrent protection can be added. Ideal for learning PWM control, H-bridge driving, and mobile communication..

Parts Used:

1. Microcontroller (Arduino Uno/Nano or ESP32) – processes Bluetooth commands and generates PWM
2. Bluetooth Module (HC-05/HC-06 or ESP32 built-in BLE) – wireless link with the smartphone
3. Motor Driver (L298N / L293D / BTS7960) – drives the DC motor; supports direction & speed
4. DC Motor (6–24 V as required) – load to be controlled
5. Power Supply – regulated supply for logic (5 V/3.3 V) and motor (separate rail)
6. Protection Components – fuse, flyback diodes (if not in driver), heat sink
7. Wiring & Connectors – reliable connections between modules
8. Optional: Encoder (Hall/Optical) – closed-loop speed feedback & PID control
9. Optional: Potentiometer/Buttons – local manual control fallback
10. Optional: OLED/LCD – display speed, direction, connection status