Here is a big piece of the puzzle I've been working on, on and off , for the past couple of months:
A 16 channel relay board. To be controlled by an arduino, to be controlled by an arduino, to talk with yet another arduino.
Pictured here is one of the work in progress shells, final prints were in a nice black filament. With the NO and NC connections from the relays I could wire one relay for off/on and the other for low beam/high beam (although for headlights I am actually using these relays to switch bigger relays that will handle more current), each relay can handle 10A max. (I measured the current draw of each thing I intended to control with this make sure I was not going to melt my hard work). Not pictured is the power distribution circuit. The power supply is split up into 4 banks and for each channel there is a thermo fuse.
Currently I am directly controlling wipers, horn, blinkers,reverse light, and by way of bigger relays the headlights.
The main function of this board is to take in a command and switch a relay. It receives commands from a second arduino:
It seems in my rush to get this working I neglected to take a picture of the guts. Observe the small box temporarily taped onto the relay controller box.
This is the input control box. It talks to a third arduino with a radio transceiver as well as adding 7 channels of 5v I/O. The reverse switch is wired into one of the I/O's and with the radio transceiver I am reading input from the steering wheel, the third arduino.
This might have been the most amount of time I have spent on something.
I wanted buttons to press, a joy stick to navigate on the screen, compact knobs for the wipers and headlights.
And I did it.
All of the controls (minus the horn button) are mounted to a 1/8" sheet of aluminum bolted to the back of the wheel adapter, not sandwiched in between.
There are a lot of wire in this!
Lights and wipers are controlled by push button pots to allow them to also dim lights and activate the washer fluid. Along with the transceiver there is a hefty 1600mAh battery with an additional charging circuit.
The back red buttons are being used for blinkers, the black buttons will be used for menu/page switching on the dash.
Generally, the buttons on the front with be ok/cancel, media buttons etc, aside from the horn button whose purpose is most definitely a horn.
I haven't programmed these buttons yet, they will talk to the raspberry pi dash by way of the input controller's usb connection. It is almost assured that I will revise the input controller and add CANBUS communication too but that isn't needed at this moment.
And all of that combined,I was able to turn on and off my headlights while outside the car:
https://photos.app.goo.gl/4o8AhDe7R7YgQkFK6