Lock and Unlock car with Arduino Uno

Other Hardware Motors, Mechanics, Power and CNC
1

I am using an Arduino Uno with a Raspberry Pi to lock and unlock my car with my phone.

My car has a single wire which when grounded with a 1.5 K ohm or a 249 ohm resistor, it locks or unlocks.

I figured I'd have two connections, each with a different resistor. Then the Pi can send a signal via GPIO that the Arduino listens for.

Can the Uno programmatically ground an input, and can it handle the car's power?

2

DigitalWrite(pin, LOW) will set the pin to ground. You must be careful to never sink more than 40mA max (20 mA to be safe). You can use a transistor connected to the digital output to allow more current. What do you mean handle the cars power? There are many posts on this forum about powering the Arduino with the car 12V.