The Arduino’s firmware is all written in Arduino C and allows BB-8 to receive commands from a laptop and output speeds to its motors. The firmware is short and to the point, as firmware should be.
Code Summary
The code starts by setting all of the speeds to zero. When a bluetooth signal is received, it parses the command, which gives it three numbers: the signed percentage power values for the three motors. These values are normalized and the motors are then set to run at the relative speeds they were assigned. The firmware keeps doing this continuously, unless there is no command sent for 30 seconds, in which case the motors are stopped. This failsafe is included in case electrical components stop working during a run and the motors need to stop running but the bluetooth connection fails.
Libraries Used
- <Adafruit_MotorShield.h> is used for interfacing the Motor Shield. See more information in the electrical section.
- <SoftwareSerial.h> is used for feeding bluetooth commands to the Arduino via a non-default port.
More Information
The firmware for the Arduino, along with the rest of the software, can be found on GitHub.