DC Motor Speed Control Using Arduino Nano

This project regulates the speed of a DC geared motor using an Arduino Nano as the central processing unit. The system is powered by a 7.4V battery pack made from two 18650 Li-Ion cells, supplying voltage to the L298 motor driver and the rest of the circuit. A 10K potentiometer is connected to one of the Arduino's analog input pins, acting as a manual user control. As the potentiometer's knob is turned, the analog voltage changes, which the Arduino reads and converts into a digital value. To control the motor speed, the Arduino uses Pulse Width Modulation (PWM). The PWM signal is sent to the L298 motor driver, which acts as an H-bridge switching module capable of handling higher currents than the Arduino can provide directly. The L298 then delivers modulated power to the 100 RPM BO motor connected to a gearbox and wheels, effectively varying its rotational speed based on the potentiometer position. Simultaneously, the Arduino takes the calculated speed value and drives a common cathode seven-segment display to provide a visual readout of the current speed level. The entire circuit is prototyped using a breadboard and jumper wires, allowing all components to share a common ground and power distribution.