Home for the code that runs on the KORA Small Bot Motor Control (SBMC) board. Hardware design files for the board can be found in the SBMC_PCB repository.

Board functionality is broken down into tasks to be run in FreeRTOS. We use the rosserial arduino package to communicate via UART to a single board computer running the ROS node rosserial_python serial_node.py

Publised topics include:

• nav_msgs/Odometry on odom
• sensor_msgs/Imu on imu_data
• rover_msgs/SBMCTelemReeading on sbmc_telem

Topics the firmware subscribes to:

• rover_msgs/SBMCServoSetting on /servo_setting
• geometry_msgs/Twist on 'drive_setting

More information on rover_msgs can be found here.

To add: the different tasks, speed calibration procedure, PID tuning for motor control, mc33932 driver overview, shield class overview

In order to program the SBMC you must first upload the Adafruit UF2 bootloader. Since the pin mapping on the SBMC is matched to the Adafruit Feather M4 Express, the bootloader is must be chosen similarly. The featherm4.bin in the bootloader directory is version 3.10.0 for the feather m4 found at Adafruit's fork of microsofts UF2 bootloader.

If you enjoy and/or are comfortable with terminal based work, the Arduino CLI makes using an external editor or console environment muc

• Installation https://arduino.github.io/arduino-cli/installation/
• Add the adafruit board definition with

arduino-cli config init

• Edit the config file in the location shown and add Adafruit's board definition URL:https://adafruit.github.io/arduino-board-index/package_adafruit_index.json
• The file should contain a structure like

board_manager:                                                                                                                                                
  additional_urls:                                                                                                                                            
  - https://adafruit.github.io/arduino-board-index/package_adafruit_index.json

• Update the board index with arduino-cli core update-index

• Download and install IDE for appropriate platform https://www.arduino.cc/en/Main/Software.
• Add the adafruit board url to the board manager that you access though the GUI

Libraries to be downloaded by hand and placed in Arduino/libraries folder:

• https://github.com/BriscoeTech/Arduino-FreeRTOS-SAMD51
• https://github.com/sparkfun/SparkFun_ICM-20948_ArduinoLibrary

Libraries to install with IDE/CLI:

• Encoder: arduino-cli lib install Encoder
  • this one requires a few changes to get it to build on the SAMD51 chip this SBMCS uses. As of writing this, there is a PR in limbo that incorporates changes needed to support the interrupts that the SAMD51G19A chip has. I applied changes in the first two commits of this PR (21cf690 and 430004a) to my local copy of the Encoder library and its working great.
• PID: arduino-cli lib install PID
• Madgwick: arduino-cli lib install Madgwick
• NXPMotionSense arduino-cli lib install NXPMotionSense

One exception is the rosserial package. To install this library you must have a working ROS workspace with the rosserial metapackage built. Once this is done, run rosrun rosserial_arduino make_libraries.py PathToYourSketchbookLibraries which will generate the arduino library needed. For more information on getting a ROS catkin workspace setup, the ROS melodic installation homepage

Additionally, you need to change the ros.h configuration to add the correct buffer size. Under the #else, change the typedef to the following:

  typedef NodeHandle_<ArduinoHardware, 10, 10, 2048, 2048> NodeHandle; // default 25, 25, 512, 512

The SBMCS uses a SAMD51J19A with the arduino pin mapping of an Adafruit Feather M4 Express (yay opensource). This means when you want to compile SBMCS firmware that you need to target teh feather m4 express board.

In the arduino CLI, in the working directory of the sketch you want to compile (also accepts argument of sketch folder or file)

arduino-cli compile --fqbn adafruit:samd:adafruit_feather_m4

With the proper serial port specified, of course:

arduino-cli upload -p /dev/ttyACM0 --fqbn adafruit:samd:adafruit_feather_m4