So, i drive a wonderful 2004 Chrysler crossfire. i love this car. but unfortunately the dash came with a single din stereo , and controls for my hvac just above it, so if i add a single din pop out screen it covers my dials... useless. so i figured i would ask you guys about this, i was wondering if by using an arduino could i digitally control my HVAC controls via an android app? a tablet? the controls use switches and buttons , but im pretty sure thats something can be controlled with a potentiometers? or some form of digital control? im very much a newb looking for someone to set me straight here. the fan blower as 6 speeds, and a climate control dial that freely spins up and down. the next control is the blower mode, which has 12 settings i believe but there are three that over lap so 9. then there is the recycle and rear window heater. is this viable at all?
Generally this sort of thing is possible, but you'd need to determine exactly what the existing controls connect to electrically in the car, before you could begin to design some circuitry to connect to the Arduino to mimic the existing controls.
Android communications are best achieved using Serial over Bluetooth. using the HC05 or HC05 modules (which are cheap and readily available)
However not all tablets have bluetooth.
If you want to use an existing tablet that doesn't have Bluetooth, you can use a USB connection if your tablet supports USB host mode aka OTG (most have this even if its not in the spec)
Other alternatives are using Wifi
But anything other than Bluetooth gets increasingly complicated to program on both ends.
You will also need to write your own Android App, or you may be able to use one of the Menu builder apps (which cost money), however those apps may not give you the user interface you want.
Overall, this is totally possible, but is not a project for someone who is new to hardware and software development.