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

Arduino

In Arduino IDE, go to tools->Manage Libraries ... and install: - “Adafruit BNO055”

Verify and upload andino_firmware.ino to your Arduino board.

PlatformIO

Install dependencies:
```
sudo apt-get install python3.10-venv
```

Install PlatformIO:

curl -fsSL -o /tmp/get-platformio.py https://raw.githubusercontent.com/platformio/platformio-core-installer/master/get-platformio.py
python3 /tmp/get-platformio.py

Add PlatformIO to your $PATH:

echo "PATH=\"\$PATH:\$HOME/.platformio/penv/bin\"" >> $HOME/.bashrc
source $HOME/.bashrc

Build and upload the firmware:
- If you’re using an Arduino Uno:
```
pio run --target upload -e uno
```
- If you’re using an Arduino Nano:
```
pio run --target upload -e nanoatmega328
```

Description

Via serial connection (57600 baud) it is possible to interact with the microcontroller. The interface is described in the 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, (rebooting 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. (~3.14 rad/sec)