You need the following libraries:
- SoftwareSerial (built in)
- LiquidCrystal (built in)
- aJson, great JSON library (https://github.com/interactive-matter/aJson)
Hardware used:
- DFRobot LCD Keypad Shield
- Arduino Uno
- Keyes_SJoys joystick (http://www.plexishop.it/en/modulo-joystick-keyes-sjoys.html)
Trying an approach suggested by https://github.com/XRobots, the controller doesn't broadcast to the robot: the robot requests controller status through a JSON {"command": "somecommand"} and the controller responds with its current status.