Easy PID Motor Controller (EPMC) C++ Library

This library helps communicate with the Easy PID Motor Controller Module (i.e EPMC MODULE) in your PC or microcomputer linux c++ robotic project (as it depends on the libserial-dev package), with the epmc_setup_application.

you can use it in your microcomputer robotics project running on linux (e.g Raspberry Pi, PC, etc.)

A simple way to get started is simply to try out and follow the example code in the example folder

How to Use the Library (build from source)

• install the libserial-dev package

  sudo apt-get update

  sudo apt install libserial-dev

• Ensure you have the EPMC MODULE interfaced with your preferred motors, setup the encoder and PID parameters with the epmc_setup_application.

• Download (by clicking on the green Code button above) or clone the repo into your PC using git clone

Note

you can use this command if you want to clone the repo:

git clone https://github.com/robocre8/epmc_serial_cpp.git

• check the serial port the driver is connected to:

  ls /dev/ttyA*

  you should see /dev/ttyACM0 or /dev/ttyACM1 and so on

• A simple way to get started is simply to try out and follow the example motor_control.cpp code.

• make, build and run the example code.

  cd into the root directory

  mkdir build (i.e create a folder named build)

  enter the following command in the terminal in the root folder:

  cmake -B ./build/

  cmake --build ./build/

  ./build/two_motor_control

  ./build/four_motor_control

• You can follow the pattern used in the example two_motor_control.cpp and four_motor_control.cpp in your own code.

Basic Library functions and usage (Two Motor Support Control)

• connect to epmc_driver shield module

  epmc_serial::EPMCSerialClient controller

  //ensure you set/call supportedNumOfMotors() before connect() as below:

  controller.supportedNumOfMotors(epmc_serial::SupportedNumOfMotors::TWO);

  controller.connect("port_name or port_path")

• clear speed, position, e.t.c data buffer on the EPMC module

  controller.clearDataBuffer() // returns bool -> success

• send target angular velocity command

  controller.writeSpeed(motor0_TargetVel, motor1_TargetVel)

• send PWM command

  controller.writePWM(motor0_PWM, motor1_PWM)

• set motor command timeout

  controller.setCmdTimeout(timeout_ms)

• get motor command timeout

  controller.getCmdTimeout() // returns std::tuple -> bool, float

• read motors angular position and angular velocity

  controller.readMotorData() // returns std::tuple -> bool, std::vector (pos0, pos1, vel0, vel1)

• read motors angular position

  controller.readPos() // returns std::tuple -> bool, std::vector (pos0, pos1)

• read motors angular velocity

  controller.readVel() // returns std::tuple -> bool, std::vector (vel0, vel1)

• read motor maximum commandable angular velocity

  controller.getMaxVel(motor_no) // returns std::tuple -> bool, float maxVel0 or maxVel1 based on the specified motor number

• while these function above help communicate with the already configure EPMC module, more examples of advanced funtions usage for parameter tuning can be found in the epmc_setup_application source code

Basic Library functions and usage (Four Motor Support Control)

• connect to epmc_driver shield module

  epmc_serial::EPMCSerialClient controller

  //ensure you set/call supportedNumOfMotors() before connect() as below:

  controller.supportedNumOfMotors(epmc_serial::SupportedNumOfMotors::FOUR)

  controller.connect("port_name or port_path")

• clear speed, position, e.t.c data buffer on the EPMC module

  controller.clearDataBuffer() // returns bool -> success

• send target angular velocity command

  controller.writeSpeed(motor0_TargetVel, motor1_TargetVel, motor2_TargetVel, motor3_TargetVel)

• send PWM command

  controller.writePWM(motor0_PWM, motor1_PWM, motor2_PWM, motor3_PWM)

• set motor command timeout

  controller.setCmdTimeout(timeout_ms)

• get motor command timeout

  controller.getCmdTimeout() // returns std::tuple -> bool, float

• read motors angular position and angular velocity

  controller.readMotorData() // returns std::tuple -> bool, std::vector (pos0, pos1, pos2, pos3, vel0, vel1, vel2, vel3)

• read motors angular position

  controller.readPos() // returns std::tuple -> bool, std::vector (pos0, pos1, pos2, pos3)

• read motors angular velocity

  controller.readVel() // returns std::tuple -> bool, std::vector (vel0, vel1, vel2, vel3)

• read motor maximum commandable angular velocity

  controller.getMaxVel(motor_no) // returns std::tuple -> bool, float maxVel0 or maxVel1 based on the specified motor number

• while these function above help communicate with the already configure EPMC module, more examples of advanced funtions usage for parameter tuning can be found in the epmc_setup_application source code