New to open based controller boards, looking for a starting point.

Part 1

Where to begin.

I have no experience with Arduino or other open based controller boards. I am very good at figuring stuff out and coming up with new ideas, have lots of wiring and soldering experience...

Over the last year I have been looking into Arduino boards.

I want to use one for automotive purposes and I know the Arduino can do a lot more than I want to use it for.

I am looking for a list of devices to look into and learn about and any suggestions or better ideas.
This is a growing plan and I am opened to anything.

The short version:
-Original plan-
I want to use ground or 12v+ sensor signals to allow or deactivate a ground or 12V+ signal to a relay.
Added to list-
Activating a device for a timed period upon receiving a button activated signal.
Newest item to list-
Activating and deactivating output signals using a simple RF device.
Bonus item.
Controlling radio volume and track select with RF device.

The details.
One of my cars runs a home made water/methanol injection kit made of salvaged and modified parts.
The mechanics of the system seem complicated but are very functional.

A typical kit has a tank, a high pressure pump, hoses, a controller and misting jets... The high pressure pump is expensive and prone to overheating and failure.

A guy in Australia made a set-up that runs on turbo boost (positive pressure above atmosphere) pressure that's used to pressurize a tank that injects water/methanol through an expensive misting nozzle and operates with his engine management system.

My car is a 1988, has no controllable engine management, it was a budget build using left over car parts and stuff I made.

The water/methanol system I made consists of:

-A 12V permanent mount air compressor/tire pump.
-A 1 way check valve.
-A 300ml air tank.
-A compressor regulator (set from 85-105psi)
-An air manifold, with pressure gauge, compressor quick connect (to fill tires), 130psi pressure relief valve, compressor air line relief valve and 3/8" air line to the main tank.
-A 1.5gallon holding tank with a level sensor and pickup tube at the bottom and a pressure switch at the top.
-A liquid pressure regulator.
-A 500ml accumulator tank.
-Braided stainless hose.
-2 solenoid valves with six misting nozzles.

It's operated through pressure switches, relays, solenoid valves and switches...

-All relays are cycled on/off by ground signals and send ground signals to the devices, 12V+ is ignition switch and constant.

The pump and system has a main toggle switch and relay.
The main toggle activates the main system relay through ground signal and turns on the pump, the same toggled ground signal runs through the tank level sensor and tank pressure switch to the injection system on button.
The system on button sends a ground signal to activate the front relay.
The front relay sends a ground signal to two normally opened pressure switches set for different pressures and to an adjustable 3 way air solenoid valve used to increase boost pressure.
The two normally opened pressure switches activate the injection solenoids at the misting nozzles.

Right now the only fail safes the system is running is the float sensor and tank pressure sensor, if the tank is low or the pressure is low ground signal is cut to the injection system on button, turning off the boost control solenoid and pressure switches/solenoid valves.

I have fabricated two brackets that mount to the top of the injection solenoid valves.
They hold brake fluid level normally opened magnetic hall effect sensors to detect the electromagnet activation in the solenoid valves. The only thing I can use these signals on at the moment are led warning lights.
The Magnetic sensors will run the same ground signal that activates the solenoid injection valves.
If I use two relays per LED warning light.
I would wire the ground signal after the magnetic sensor to a normally closed relay sending ground to the LED when there is no signal from the hall sensor.
I would wire the ground signal before the magnetic sensor to a normally open relay sending 12V+ through a resistor to the LED.
So only when ground activation is sent to the solenoid valve but the magnetic hall sensor doesn't send a ground signal will the LED's light up and actually be a warning light.

If I measure no volts at the NO and NC relay outputs when the solenoid valves are activated than I could interrupt the ground signal to the boost control solenoid with a normally closed relay which would cut ground/boost only when receiving both ground and 12V+ from the NO and NC warning relays.
But I expect a tiny delay between activation signal and magnetic signal and perhaps a flicker of the light which is enough to cancel the boost cut fail safe from the magnetic hall sensor output.
And this is a lot of relays.

And it still doesn't save the engine if the solenoid valves seize or the misting nozzles get plugged, there are inline flow sensors available but without a way to use the signal than they could only be used for warning lights. Which would be a waste.

Arduino can do all this.

The car runs a stand alone extra injector controller, unfortunately it's on board map sensor only reads up to 1.5 Bar/21psi above atmosphere, so I had to keep turning boost up until it matched the fuel delivery from the extra injectors at full cycle, 30psi boost was the proper point.

The car is much faster than I expected it to be, This winter I will replace the 2.5bar map pressure sensor in the extra injector controller with a 2.5bar gauge pressure sensor that starts reading only above atmosphere pressure. So I can run less boost.

I will also add a stand alone engine timing retarding controller to pull factory ignition timing when the higher boost on water methanol is run.

I read up on some of the ways people use the timing controller and found that one of the signal inputs can trigger an immediate timing delay designed to help with starting not factory set-up engines.
They use this feature for launching when drag racing to pull timing and power to limit wheel spin when starting down the track, they use an adjustable timed relay that they turn on and stays on for 2,3 or 4 seconds then turns itself off... The timer relay costs 92$

But then I though The Arduino can do this as well.

For the Injection system on button I wanted it in a very convenient location, I decided the shift knob was easier than the steering wheel. After a lot of internet searching I decided to carve my own shift knob that put the on/off button in a spot it wouldn't get pushed accidentally.

Then I made an adjustable throw custom shift rod that puts the shift knob at a forward angle in the exact same position and height as the factory shift knob.

I am also installing a 2way 12v normally opened (flows without power) solenoid valve before the primary boost controller, so with the solenoid valve shut the car runs wastegate level, opened is preset boost without water injection.
This will give me 3 stages of boost.

But I don't want to reach for a switch on the dash while trying to drive a straight line.

I have been driving a Mazda 3 base model car that has radio and cruise control buttons on the steering wheel.
I decided to look into how they work with more than one electrical function, older wheels use an isolated metal ring and sprung pin, the metal ring would turn and stay in contact with the pin, when pressing the horn a ground signal from the steering wheels metal connection to the car passes through the Isolated ring and the sprung pin to the horn relay.
Some fancier models had multiple isolated rings and pins.
New model cars use what is called an air bag clock spring, it is made with two plastic cups and a long winding of computer cable ribbon.

I could custom fit one to my steering column or make my own.
To fit it I would have to make a custom hub adapter and move the steering wheel a little closer to the driver, The cable ribbon would have to wind and unwind around the hub adapter, I would have to give up the signal light release mechanism and always turn off my signal lights by hand.

Part 2

I searched to see if anyone tried this, I came across an expensive wireless radio controller that straps to the steering wheel but it runs all radio control signals through a jack plug or two wires.
Then I though about key fobs and universal receivers, I have installed and worked with them, could find a really thin remote controller, remove the casing, install it in leather and padding and stitch it to the metal part of the steering wheel, the battery or batteries can sit in the basket behind the horn for easy access.

Then I realized all these remotes put out a momentary switch style signal and not an on/off signal and think Arduino controllers can convert the signals to on/off.

I start searching for universal RF remotes and receivers to see if this much easier solution is possible. Those of you that are really smart are already thinking I am an idiot.
A little back history, the first time I saw an Arduino controller was quite a while ago, I was searching for a 12vdc electric motor online and ended up on an RC vehicle parts site, none of the motors where strong enough for what I wanted but I spent a while on the site reading about the Arduino Uno board they where selling and though this is awesome. When searching for Arduino automotive application most results where RC cars. Nope it still hasn't made the connection in my head. I am on the Arduino site browsing the devices having no idea what I should be looking for or what any device listed is and it finally dawns on me that Adruino components can obviously receive wireless signals in many forms.

So Arduino can also do that.

I am in over my head at the moment and don't want to look up all terms and specs for all devices sold to understand what I need to learn.
If you guys can tell me what I should look into I will gladly learn everything needed to know through searches and trial and error.

I understand automotive signals and building control signals are similar, a voltage signal or ohm sent from a sensor within a preset range 0-12v, 0-5v,0-1v, 5-0V or 0-X ohm (for most automotive applications), the signal is interpreted through programming and outputs a corresponding signal (gradual, wavelength, pulse) to a device in response.

The building control devices I work with use positive voltage signals only as inputs and outputs, grounds are all common across the board, cars use grounds as signal voltage whenever devices (brake lights, head lights, coil pulse, courtesy lights ...) require an on/off or pulsed 12v signal, minimizing the amount of live 12vdc current wire that could potentially short to the cars frame/to ground.
Do the Arduino boards require + input and output signals to operate relays and devices, I don't mind converting to positive triggers on relays and devices but would prefer to run ground with on/off opened/closed devices.

To recap I would like to:
1-Tank level opened/closed signal.
2-Tank pressure sensor (If an electric signal that flows when something is off is normally closed and doesn't is normally opened, but a valve that flow gas or liquid dormant is normally opened and those that don't are normally closed, how are pressure sensors identified? So I looked it up, like a a relay or light switch, normally closed sends no signal until activated and I somehow ordered normally opened pressure switches, they where not accurate enough to use with a normally closed relay on the injection solenoid valves but are accurate enough for low tank pressure using a NC relay ) or open/closed signal.
3, 4-Front boost pressure switch open/closed signals X2.
5, 6-Magnetic hall sensor signal with acceptable millisecond delay opened/closed signal X2.
7-8?Flow sensor signal with acceptable millisecond delay opened/closed signal, but one variable voltage output based on flow sensor could be programmed to account for both solenoids and jets combined flow.
9- Knock sensor signal, on/off signal.
10- Throttle position sensor, Potensiometer (0-1v).
11-Wideband oxygen sensor, 0-5v signal.
12- 2.5 bar manifold gauge pressure sensor 0-5v signal.
13,14,15,16 -Rf remote momentary signal (possibly 4 more for the radio).
up to 20 possible input signals.
Devices on Input 1 and 2 can be combined and read as a single signal.
Devices on Input 7 and 8 should be a potensiometer and would be 1 device not 2.

1- opened/closed signal to boost control solenoid, ignition timing control unit and injection solenoid relays from input signals 1 to 8. When inputs 3 to 6 receive a signal input 9 to 12 are monitored. Input 9, voltage signal = output 1 off. Input 10, under a certain voltage = output 1 off. Input 11, above a certain voltage = output 1 off. Input 12 below a certain voltage and above a certain voltage = output 1 off.
2- Because there are two stages of water injection and the first stage operates at boost levels below those added by the water injection boost control solenoid. I might us the shift nob injection on button to control only the boost control solenoid, 1 injection solenoid and 1 pressure switch as the 3rd stage of boost, I would monitor some of inputs 1-12 and use a warning light to signal any problems when running only the first water injection solenoid. The actual boost levels are Wastegate alone 15psi, usual boost 21psi (current limit of fuel adjust-ability) shift button ON 30psi (currently required to consume enough fuel). Perhaps have constant warning light = problem with system, Flashing light = Input 9 signal detected.
3- RF signal 13 - signal = relay for 2 way NO usual boost solenoid signal OFF (open solenoid).
....RF signal 14 - signal = relay for 2 way NO usual boost solenoid signal ON (close solenoid).
4- RF signal 15 - signal = Timing control launch timer ON for set time/ timed signal to relay.
....RF signal 16 - signal = Timing control launch timer cancel/ Cut signal to relay.

Possible outputs for radio control:
5- Volume up
6- Volume down
7- Track forward
8- Track back

I would suppose the Arduino controller can also be used to measure the time delays between input signal 3,4 and 5,6 and 7-8 and used to measure/chart the potensiometer voltage output from device 7-8.

I am only guessing what can be done with the Arduino boards and accessories, perhaps someone with knowledge