BLDC MOTOR With Web-Based Speed Control Using ESP32

Integrating wireless control into brushless direct current (BLDC) motor systems opens up exciting possibilities for applications such as remote-controlled cars, robots, and other innovative systems.

- MAHESHWARAN.S AND K. VAIRAMANI

BLDC motors are commonly operated using a driver or a remote-controlled controller paired with an electronic speed controller (ESC). Adding Wi-Fi connectivity to enable control via a laptop or personal computer further enhances their versatility.

This motor system utilises a BLDC motor, an ESC, and an ESP32 to enable wireless operation. Bill of Materials table lists the required components, while the author’s prototype of the BLDC motor controller is depicted in Fig. 1.

An ESC is vital in operating BLDC motors. It regulates the motor’s speed, direction, and overall performance by controlling the power delivered to the windings.

The 3S 12V battery powers the BLDC motor and other components, ensuring efficient system operation. Its stable output makes it suitable for driving ESCs and maintaining consistent power for the ESP32 module. Fig. 2 shows an electronic speed controller.

Working principle

The ESC manages the timing and duration of current flow through the stator windings, effectively controlling the rotor’s rotation. It operates on principles such as pulse width modulation (PWM), phase sequence, sensorless control, and sensor-based control.

The ESC uses PWM signals to control transistors, managing voltage and current delivered to each phase. It simulates a rotating magnetic field by rapidly switching phases on and off.

The ESC energises windings in a specific sequence (A, B, C) to create continuous rotation. As the rotor moves, the ESC adjusts which windings to energise based on sensor feedback or back electromotive force (EMF).

Many ESCs utilise sensorless controllers that estimate rotor position from back EMF generated during motor operation, simplifying designs and reducing costs. In some applications, sensor-based controllers (like Hall effect sensors or encoders) provide precise feedback on rotor position, enabling accurate control.

ESP32 for BLDC motor