This code is for the CarCar RC car prototype platform built on the Traxxas Fiesta Rally 1/10 scale RC car. The current hardware configuration includes:

• Rev Spark motor driver
• Raspberry Pi
• Adafruit PCA9685 PWM driver module
• Reach RTK precision GPS unit
• Adafruit/Bosch BNO055 IMU

Future hardware will include:

• Nvidia Jetson
• Zed stereo camera
• (other hardware TBD)

The codebase for CarCar is now contained fully within the harcar_catkin_ws folder, which is a ROS "catkin" workspace.

The remaining scripts, listed below, are from the pre-ROS implementation, which followed a pre-determined path, and are for historical reference only.

Includes PWM driver logic for smooth control of car. Abstracts PWM commands and exposes simple methods set_speed and set_steer, each of which accepts a pct_speed or pct_steer integer percent value argument from -100 to +100 representing the spectrum from full-speed reverse to full-speed forward, and full-left and full-right turns, respectively. The percent value is optional and if not specified will set speed/steer to zero. Each method also accepts an optional rate argument which defaults to the (mostly empirically-determined) maximum rate of change in speed/steering. A reduced rate can be specified for smoother motion.

Reads a set of predetermined waypoints from a CSV file, sets the speed to a constant (very slow) value, and then begins reading RTK positioning data. Two consecutive data points are used to determine heading and the difference between this heading and the heading to the next waypoint is used to set the steering appropriately. Note: This is the simplest and least sophisticated way to control the steering - better methods to come.