NuttX ESP32-C6 Motor Control and Sensing

This repository contains the source code for the article series "NuttX for Motor Control and Sensing" published on Espressif's Developer Portal.

• Part 1: NuttX for Motor Control and Sensing - Basic motor control with PWM and quadrature encoder
• Part 2: NuttX Motor Control and Sensing: Data Transmission - TCP server implementation and IMU data streaming

Overview

Demonstrates how to use multiple ESP32-C6 peripherals with NuttX RTOS:

• Motor Control PWM (MCPWM) for DC motor speed control
• Quadrature encoder for speed measurement
• ADC for potentiometer position reading
• IMU via I2C for vibration analysis (coming soon)
• Wi-Fi connectivity for data streaming (coming soon)

Hardware Requirements

• ESP32C6-DevkitC
• CHR-GM25-370 6V DC Motor with integrated gearbox and quadrature encoder
• L298N H-Bridge motor driver module
• 10kΩ linear potentiometer
• GY521 IMU module (MPU6050)

GPIO Connections

• GPIO 20: MCPWM output to H-Bridge
• GPIO 3: ADC input from potentiometer
• GPIO 10: Quadrature encoder channel A
• GPIO 11: Quadrature encoder channel B
• GPIO 5,6: I2C bus, SDA and CLK

Building

This repository is designed to be used as an external application for NuttX. To build:

1. Clone this repository

2. Link it to your NuttX apps directory:

   ln -s <path-to-this-repo>/apps/ $NUTTX_PATH/apps/external

3. Configure NuttX: You can partially configure this project by enabling small parts of it, or, skip to item 3.4 to configure all peripherals at once.

   3.1. Motor control, accelerometer and quadrature encoder

   # Load base configuration
   ./tools/configure.sh esp32c6-devkitc:nsh
   
   # Merge with provided defconfig
   kconfig-merge -m .config ../apps/external/motor_sensing/config/defconfig
   make olddefconfig

   3.2. Add Wi-Fi support:

   kconfig-merge -m .config boards/risc-v/esp32c6/esp32c6-devkitc/configs/wifi/defconfig
   make olddefconfig
   

   3.3. IMU Support

   kconfig-merge -m .config boards/risc-v/esp32c6/esp32c6-devkitc/configs/mpu60x0/defconfig
   make olddefconfig

   3.4 Alternatively, use the complete defconfig with all the above and IMU configured:

   # Load base configuration
   ./tools/configure.sh esp32c6-devkitc:nsh
   
   # Merge with provided FULL defconfig
   kconfig-merge -m .config ../apps/external/imu/configs/imu_wifi/defconfig
   make olddefconfig
   

4. Build and flash:

   make
   make flash ESPTOOL_BINDIR=./ ESPTOOL_PORT=/dev/ttyUSB0

Usage

After flashing, run the application from NSH:

nsh> msense

The application will display:

• Command speed (from potentiometer)
• Actual motor speed in RPM (from encoder)
• Sample time and encoder configuration

You can run this application in the background and start the imu program, which reads the accelerometer and transmits the data wirelessly, using sockets.

nsh> imu
MPU60x0 Accelerometer Test
Sample Rate: 20 ms (50 Hz)
TCP server starting on port 5000
Waiting for client connection...

On the client side, run the run_client.sh bash script provided in this repo. Make sure to set the proper IP address and port.

$ ./imu_client.sh 
Connecting to IMU server at 10.42.0.199:5000...
X:  1.168  Y: -0.077  Z:  0.145

Make sure to check the articles for more detailed instructions on this application.

License

This project is licensed under the Apache License, Version 2.0 - see the LICENSE file for details.