ROS-for-Jetbot-cpp

ROS nodes and driver libraries for NVIDIA JetBot with Jetson Nano. The libraries are aimed for the Jetbot Kit provided by WaveShare.

Synopsis

This is work still under construction, although you can control the (WaveShare) Jetbot with a game controller. The code is in 2 folders one for the Driver Libraries and one for the ROS nodes.

Driver Libraries

The driver library structure is based on a Library set I first made for the RPI. Here a short overview:

• i2c --> Library provides the communication to the i2c bus
• ina219 --> Library provides the communication to the ina219 chip uses i2c.
• ina219_poc --> Program to test the ina219 library.
• pwm9685 --> Library provides the communication to the pwm9685 chip uses i2c.
• rpmsensor --> Library provides the communication to the an Arduino with rpmsensors, uses i2c.
• motorcap --> Library to run the motors, uses pwm9685 and i2c.
• motorcap_poc -> Program to test the motorcap library.

Notes:

• The libraries need to be compiled with the Position Independent code option (-fPIC)
• The rpmsensor library interfaces to an Arduino, see: RPM-Sensors

Ros-nodes

The Ros nodes are split over a Linux PC and the Jetson Nano. Each package where appropriate has launch- and parameter file. There is also a package with to start-up launch files on for the PC and one for the Jetson. Here a short overview:

• jetbot_msg -> Contains the messages used. Not all are necessary used now.
• teleop_joy_twist -> Uses the info published by the standard joy package and convert it to a telep/cmd_vel message.
• twist_mux -> Takes a teleop or auto cmd_vel publish that it also published a heartbeat.
• jetbot-node -> Takes the cmd_vel and steers the motors. It also subscribes to the heartbeat and stops the motors when no heartbeat is received for a specific periode.
• jetbot_stats -> Publishes statistics from the jetbot.
• jetbot-start -> Contains launch files one to start the nodes on the Jetbot and one to start the nodes on the PC.

Graphical Overview