Using the remote

 With lots of challenging challenges, it has felt easy to ignore that the Farmyard Tours was to be remote control and not autonomous, so we needed a solution which was a bit more dextrous than a keyboard. Using a full RC set with adapters was always an option, but a more personal system was preferred and an almost universal games controller format was chosen. 

Could have been any brand, but it turned out as a low cost PS3 controller from a no-name Chinese source. As the main Pi controller just wanted a data feed it could translate, the interface chosen to the controller was Bluetooth run by a small ESP32 module dedicated to the communication. This was a lot less bother than direct comms and meant that the controller Pi wasn't cluttered with noisy code. Here is a larger dev board for testing, and mounted on a test chassis. The communication is via serial over USB and a simple handshaking option is used to request data from the PS3. 

One of the issues with this configuration is that when the controller times out and disconnects, the ESP32 code can't reconnect, so an extra pin was dedicated to reboot the ESP32 into connection mode again. 

Here's a brief video of the test chassis twirling in the arena..........and negotiating a bit of garden.

....and negotiating a bit of garden.