🛠 Automate a Robot Chassis with the 4-Encoder Driver

Objectives

This tutorial aims to configure the M5Stack 4-Encoder Motor Driver module to automate a small robot chassis. You will learn how to initialize I2C communication, define motor parameters, and execute an autonomous movement sequence (forward, turn, stop) using closed-loop speed regulation. This use case illustrates simple automation in mobile robotics.

Required Materials

• M5Stack 4-Encoder Motor Driver Unit (DRV8837DSGR)
• Compatible microcontroller (e.g., M5StickC Plus2 or Core2) with Grove I2C port
• 4 6-wire gear motors (TT type) with integrated encoders
• External DC power supply 6-12V (or USB if load is low)
• Grove cables and PH2.0-6P motor cables
• Computer with Arduino IDE installed

Steps

1. Hardware Assembly: Connect the four PH2.0-6P connectors to the motors. Ensure encoder wires are correctly aligned. Plug the module into the main board's Grove I2C port.
2. Power Supply: For powerful motors, connect an external DC source (6-12V) to the module's power port. For small TT motors, Grove port power (5V) may suffice, but ensure current stays under 1.2A per channel.
3. Software Configuration: Open Arduino IDE. Install the M5Stack_MotorDriver library or the one provided by M5Stack for this module. Select your board and corresponding serial port.
4. Code Initialization: Start with Wire.begin(). The module uses default I2C address 0x24. Initialize the four motor channels in closed-loop mode.
5. Program the Sequence: Write a moveRobot(speed, duration) function that sends speed commands to the four motors. To turn, reverse the direction of motors on one side compared to the other.
6. Upload: Upload the code to the microcontroller.

Verification

• The module's RGB WS2812C LED should light up (indicating power and activity).
• Motors should rotate synchronously during the "forward" command.
• During a turn command, motors on one side should rotate in the opposite direction.
• If motors do not move, check the I2C address with a standard I2C scanner.

To Go Further

Explore closed-loop position control for precise movements. You can add a distance sensor to avoid obstacles, creating more complex automation. Try modifying the I2C address to connect multiple modules on the same bus.