DRV8871 Motor Driver Tester for ESP32-C3 & N20 DC Motor

PlatformIO test codebase for controlling a DC Geared Mini Motor (N20 6V 100RPM) using an ESP32 Mini C3 microcontroller and a DRV8871 H-Bridge motor driver powered by a 12V power supply.

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⚡ Hardware Connections

Wiring Diagram

Component Pin	Connects To	Notes
DRV8871 IN1	ESP32-C3 GPIO 4	PWM Control Pin 1
DRV8871 IN2	ESP32-C3 GPIO 5	PWM Control Pin 2
DRV8871 GND	ESP32-C3 GND & 12V PSU GND	Common Ground (Mandatory!)
DRV8871 VM	+12V Power Supply	Driver Power Input (6.5V - 45V)
DRV8871 OUT1	Motor Terminal 1	N20 Motor Output
DRV8871 OUT2	Motor Terminal 2	N20 Motor Output
ESP32-C3 5V/VBUS	5V Power / USB	Power ESP32 via USB or step-down buck

Warning

Motor Protection Guard (12V Supply with 6V Motor): The N20 mini motor is rated for 6V, while the main power supply is 12V. The code automatically limits the maximum PWM duty cycle to 50% (128/255). This provides an effective average output voltage of ~6V across the motor terminals to prevent winding burn-out or gear overheating.

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🚀 How to Build and Upload

1. Requirements

• PlatformIO Core CLI or PlatformIO IDE extension for VS Code.

2. Build the Project

Open terminal in the root directory of this project and run:

pio run

3. Upload to ESP32 Mini C3

Connect your ESP32 Mini C3 via USB and run:

pio run -t upload

4. Open Serial Monitor

Launch the serial monitor at 115200 baud:

pio device monitor

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🎮 Serial CLI Commands

Once the monitor is running, type commands into the terminal and press Enter:

Command	Action
f or F	Drive motor FORWARD at configured speed percentage
r or R	Drive motor REVERSE at configured speed percentage
s or S	STOP (Coast / Float mode)
b or B	BRAKE (Fast decay mode)
0 - 100	Set speed percentage (e.g. 75 sets speed to 75% of max safe 6V level)
t or T	Run automated RAMP SWEEP test sequence
h or ?	Display Help Menu