AutoTop DIY

[JayG]

Originally Posted by oldskool73

I've been thinking about possible additions to this, I'm good at the code side but rubbish at the electronics, so wondering if someone with more knowledge could chime in on my possibly stupid ideas/questions below...

1) The nano has a VIN that accepts +12v, any reason we can't just use that and skip the Voltage Regulator?

2) The nano has optional built in pullups on the inputs, any reason we can't use them to wire the switch side to GND (instead of +5v) and go directly to pins 8 & 9 without the need for the resistors? (https://www.arduino.cc/en/Tutorial/DigitalInputPullup)

3) There's a speedometer input wire to the radio (GR/PK), does anyone know what kind of output this provides? I'm assuming if we can figure it out, it could it be used to provide an input that locks the auto open over a certain speed?

You want the voltage regulator to protect the nano. While a car is a nominal 12v, in reality it can get higher. Sure the nano can probably handle a few more volts than 12, but for a buck or 2, why take the chance