I want to read the data line from a device that normally interfaces with a controller. It has 3 pins, 3.3v power, gnd, and data. I don't need the power line since the Arduino will be USB powered and I obviously don't want to just connect it straight to ground. What would be the best way to handle this without introducing extra hardware components. Can I just connect the power to an input pin, and then I can use that to see if the device is on?
I'm using an Arduino Mega2560