Sunflower

This repository holds the code required to run the UBC UAS Antenna Tracker.

Dependencies

Dynamixel SDK: https://emanual.robotis.com/docs/en/software/dynamixel/dynamixel_sdk/overview/ Adafruit CircuitPython LSMDS91: https://github.com/adafruit/Adafruit_CircuitPython_LSM9DS1

Design History

Prior to September 2020

Sunflower is known as Antenna Tracker. https://gitlab.com/ubcuas/rcomms/rcomms2019

Key	Value
Computer	Raspberry Pi 3
Microcontroller	OpenCM 9.04

September 2020 - Present

Sunflower experienced major hardware and software changes.

Key	Value
Computer	Odroid XU4
USB Converter	U2D2

The current conne

Odroid XU4 Common Issues and Resolutions

This code uses Adafruit CircuitPython

Constants

USB Device Names

These port names can be found by checking which USB interface Linux has assigned to the devices. U2D2_PORT_NAME = "/dev/ttyUSB0" GPS_PORT_NAME = "/dev/ttyUSB1"

Dynamixel Control Table

This control table is dependent on the motor model. For more information, consult this website: https://emanual.robotis.com/docs/en/dxl/ Your control table will be under 2. Control Table on your motor's webpage.

xl430_w250_control_table = {
    'torque_enable':64,
    'goal_velocity':104,
    'goal_position':116,
    'load':126,
    'velocity':128,
    'position':132,
    'max_position':48,
    'min_position':52,
    'velocity_limit':44
}

The table above was extracted from this page: https://emanual.robotis.com/docs/en/dxl/x/xl430-w250/#control-table-data-address

Dynamixel Control

Code used to control the motors can be found in dynamixel_interface.py

For a group of dynamixels, you will need to:

Initialize an interface like so:

# Initialize the interface on U2D2_PORT_NAME with baudrate of 57600 using
# Dynamixel Protocol 2.0
motors = DynamixelInterface(xl430_w250_control_table, debug=True)
motors.connect(U2D2_PORT_NAME, 57600, 2.0)

It is currently assumed that both motors are the same model. The interface requires a control table for initialization. The debug parameter can be set to True for verbose output. It is False by default.

For any dynamixel in this group, you will need to:

• Register it using their ID
• Set your desired load limit motors.register_motor(1, load_threshold=5)

Issues

If you come across a bug or believe that something is lacking, feel free to create an issue. Direct any questions to the maintainer specified below:

Contact Alexander Chudinov at [email protected] or on Slack