Hoping the brainstrust can point me in the right direction!
I’m finalising the build of my Racecar and looking to incorporate some further functionality on my steering wheel. I have already repurposed some of the wiring from the stock car (2015 Renault Megane RS275) but looking to add 5 more buttons to control the Pi based lap timing/data/telemetry system.
Space is very limited and I’d prefer to not have to run a curly cable and additional wiring from the wheel. My idea is to use an appropriate BT module that can be programmed to emulate the 5 additional keys, just not sure where to start. I am relatively handy with electrical stuff (soldering is probably a bit average!) and do have some reasonable tech skills, but certainly no programmer.
I have momentary buttons ready mounted just need the smart bits in as small a form factor as possible, bonus would be the ability to run off 12v as there is power in the steering mounted button housing.
One approach you could take would be to re-use the existing wires to transmit power and CANBUS to a microcontroller on the wheel. This would definitely be enough for sending button pushes, but could be expanded to encoders, pots, or even displays if you were keen enough.
I know teensies have an excellent CAN library and peripheral, but they are hard to come by these days.
Maybe a simpler protocol than CANBUS could work, but you definitely want something with electrical and data robustness (RS485 and checksums)
Let me know if you have any questions on this as I’ve delved pretty deep into this for my university racing team.
-James
Thanks James, problem with CANBUS is there is no connectivity from the Raspberry Pi to the CANBUS system in the car, the Pi is just a display for the data system. I guess you could go to the trouble of setting up a controller etc, but it’s a complicated approach, plus I am out of spare wires on the wheel.
A small bluetooth setup seems to be a simple approach, just need some ideas on what’s required.
Perhaps a simpler option would be a PISO shift register? You’d only need 4 wires (VCC, GND, CLK, DATA). Then your microcontroller can take that serial data and record it: https://learn.sparkfun.com/tutorials/shift-registers
To be honest just seems a little too complex for a simple issue. I was thinking of a solution based on one of these Adafruit Feather M0 Bluefruit LE | ADA2995 | Core Electronics Australia as it will fit inside the enclosure and I could run a small battery. It’s not “mission critical” but would like it to be reliable without over engineering it. It doesn’t need to integrate into the car CANBUS or be more complex than a simple bluetooth connection.
