Arduino Automotive Relay Controller

Development Boards Arduino
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I have a little bit of an unusual need. I want to make a touch screen widget that will control relays on my truck.

I will need it to: accept and monitor for changes on multiple inputs at the same time, have a touch screen button interface, have the ability to reprogram the screen to change the button layout without removing the module from the vehicle, be able to control multiple (probably no more than 12) relays and potentially at the same time.

I am far from an experienced Arduino user. I bought an Arduino a while back but never ended up using it for anything. What sort of screen do you think would work best? Anything I should watch out for? An Arduino will only output 5v on the trigger pins correct? If thats the case, I’ll probably have to use transistors to switch the 12v for the relay trigger.

If you guys could give me a little guidance, I would appreciate it. Thanks!

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Optoisolator: Arduino lights an LED, photosensor reads it, load utterly isolated from Arduino. They come in 1, 2, 4, 8 channels, maybe more

generic DC relay advice. Use commutating diodes. this is not a special kind of diode, it is a particular use of a generic diode. you want 2:

one across the coil, reversed biased - cathode to +VDC. The coil throws a huge spike of negative DC when power to the coil is cut and he magnetic field collapses. this diode eats that spike

second one from the load to ground, reverse biased. this eats any spike from the load to ground - the fat blue arc you see when you disconnect a load by yanking the wire

https://www.allaboutcircuits.com/textbo … -circuits/

https://www.allaboutcircuits.com/textbo … ing-diode/

https://en.wikipedia.org/wiki/Flyback_diode