RPI - Which GPIO pins are 0V at statup?

Question

So I'm doing a project today with the Raspberry Pi 2 Model B and I realized that some (not all) of the GPIO pins output 3.3V at startup (I mean the data pins, not the power output pins). I cannot have it output 3.3V since I'm using the RPI to control a quadcopter and that would cause a mess if the motors ran at full speed at bootup. So do you guys know which pins are 0V (off) at startup and I can control using WiringPi?

Answer 1

All the GPIO pins start as inputs (except the 2 used for serial console), so they may appear "high" if read with a voltmeter, but you could easily override this.

gpio readall will show state.

I believe you can change the startup state (you could search just as easily as I). In the brief period before the config is read they must be indeterminate. You need some other method if you wish to manage state.

Answer 2

I just got I2C and WiringPi installed a few hours ago. To expand on what @Milliways said, I rebooted and checked the output of gpio readall. See the attached image. It appears most all the pins start as inputs.