EPMC Documentation

Easy PID Motor Controller (EPMC) User Documentation

Imagine sending actual angular speed commands (not PWM commands) to your DC motor and seeing it running at that commanded speed. This is exactly what the Easy PID Motor Controller (EPMC) helps you to accomplish.

It is an easy-to-use PID motor controller system for controlling the angular speed of geared DC motors with quadrature encoders via angular speed commands in rad/sec rather than the traditional PWM commands. It consists of a motor driver (i.e. L298N Driver IC or any other motor driver that can be controlled using the Arduino PWM), a microcontroller, and a GUI Application that enables one to control motors easily and set up motor PID parameters.

It also provides a USB serial and I2C communication interface with ROS2, Arduino, Python, and Cpp libraries for easy interfacing with one's preferred project.

Custom EPMC Interface Board can also be made for other motor drivers (as long as they can control motor speed using the Arduino PWM). This may be due to the higher current requirement of the motor you intend to use for your project which the L298N (i.e. L298N EPMC Module) cannot provide. If you need a solution like that you can contact me: visit the robocrea8

It can easily be used by robotics or ROS hobbyists, students, learners, researchers, engineers, etc.

The Common Motor Speed Control Problem (Traditional PWM Approach)

Whether you are a hobbyist, maker, engineer, student, or researcher, you usually would opt to control the speed of a DC Motor using PWM Commands from a microcontroller (e.g. Arduino UNO, etc.) using a motor driver like the L298N Driver Module (or any other motor driver module).

While this control method is simple and easy, the only drawback of this control style is that it is an open-loop control and does not allow you to command a desired angular speed easily. This generally poses a lot of limitations in their uses, especially in more advanced robotics (e.g. wheeled mobile robotics) projects requiring precise speed controls.

To achieve precise angular speed control with this traditional PWM control style, one would need to understand quite a bit of control theory and signal processing calculations, write more control and signal processing code, and possibly add an extra layer of circuitry, all of which can become cumbersome and might not be easy to integrate into one’s desired project. All these require a good level of control expertise.

The Easy PID Motor Controller (EPMC) easily solves and abstracts all these problems so you can focus more on building your projects with good controls being made readily available.

In summary, the Easy PID Motor Controller (EPMC) provides the following:

• Easy interfacing with a geared DC motor with a quadrature encoder.

• Easy setting up of PID control parameter gain for the interfaced motor via its GUI application - epmc_setup_application.

• Easy motor angular speed commands in rad/sec (not PWM) and getting feedback on the motor’s actual angular position and angular speed.

• Easy integration with ROS2 (microcomputer or PC) projects with its ROS2 control package - epmc_ros2_control.

• Easy integration with Arduino projects with its I2C library - epmc_arduino.

• Easy integration with a microcomputer-based (Python or Cpp) project with its epmc_python and epmc_cpp library.

If you are using Ubuntu 22.04 LTS, you can download the EPMC executable application from here

The EPMC Specification

• Recommended Supply Voltage – 7v to 12v

• Motor Output Supply Current (Max) – 2A (i.e. should be used with geared DC motors whose stall current is not greater than 2A or 2.5A)

• Communication Interface - USB Serial and I2C

• Easily integrates with ROS2 and Arduino (as well as Python and Cpp) projects.

• Angular speed commands are in rad/sec.

• Angular speed feedback in rad/sec.

• Angular position feedback in radians.

EPMC Applications

• Robotics (Arduino, ROS2, Python, and C++)

• Precise Motor Speed Control

EPMC Tutorials (Usage Guide)

• How to setup DC motor PID speed control with the EPMC

• How to use the EPMC with ROS2

• How to use the EPMC with Arduino

• How to use the EPMC with Python and Cpp projects

Checkout These Libraries that Made The EPMC Project a Success

Check out these Github repos of libraries that went a long way in developing the Easy PID Motor Controller ATmega328 microcontroller computational system. You can use them in your projects also (Ensure to star them).

• simple_pid_control - PID Arduino library based on the PID control series by Prof. Kelvin Lynch of Northwestern Robotics, developed by samuko-things.

• l298n_motor_control – Arduino library that helps you easily control with PWM the l298n driver module (or any other driver module with a similar control style), developed by samuko-things

• adaptive_lowpass_filter - Arduino code for implementing one and two-order lowpass filter in your Arduino signal processing project/code by Curio Res. Adapted by samuko things.

• quadrature_encoder_velocity_and_position_calculation - sample Arduino code on how to compute rotational velocity and position with a quadrature encoder, developed by samuko-things.

• Serial_comm_pyserial_and_arduino - a backend-API-style serial communication code between Pyserial and Arduino that can be adapted to any project, developed by samuko-things.