andino_firmware

andino_firmware

Firmware code to be run in the arduino microcontroller for proper control of the motors of the robot.

Connection

Check encoder_driver.h and motor_driver.h files to check the expected pins for the connection.

Installation

Verify and Upload andino_firmware.ino to your arduino board.

Description

Via serial connection (57600 baud) it is possible to interact with the microcontroller. The interface is described in the andino_firmware/commands.h file. Here are the most used commands:

• Get encoder values: 'e'
• Set open-loop speed for the motors[pwm] 'o <left> <right>'
  • Example to move forward full speed: 'o 255 255'
  • Range [-255 -> 255]
• Set closed-loop speed for the motors[ticks/sec] 'm <left> <right>'
  • Important!: See the Test it! section.
• Set PID values: 'u <kp> <kd> <ki> <offset>'

Note: Remember the carriage return character at the end of the message.

Test it!

A serial port connection must be created at 57600 bauds. You can use the serial monitor from Arduino IDE for example.

• Open loop verification:

  • Send o 255 255 to go full speed
  • Send o 0 0 to stop it.

• Read the encoders

  • Send e to get the encoders values.

• Get the ticks per revolution of your motor.

  • First set the encoders to zero, (reeboting with r).
  • Then rotate your motors as many revs you want,(say 10 for example) and then divide the encoder ticks per the number of revs. -> Then you get the ticks per revolution. Save this value, it is calibration for the control loop.

• Closed loop verification

  • Send m <tps> <tps> where tps stands for ticks per second. For example if your motor-encoder system gets 700 ticks per revolution then sending m 700 700 will rotate both motors at 1 rev per sec. (~3.14rad/sec)