So I just got the new Raspberry Pi 2 Model B (I'm still confused on the naming system but it's the new quad-core 1 GB version). Last night I was playing with the Python GPIO library and measuring pins using my multimeter since I don't have any LEDs or anything right now.
In short, no matter what I did I could not read any voltage on the GPIO outputs I activated, though the GPIO function to read an output's current state would think they are set HIGH. I could see 5V and 3.3V on some of the power pins, however there was another pin (forget which one) which was supposed to be a GPIO yet I would always read 3.3V on it regardless of the output state, making me think that the new model pinout does not match the online pinout diagrams! (I was using GPIO.BOARD mode by the way)
Did the pinout change compared to the older models? Am I reading the diagrams wrong? Or could my GPIO be defective?
Sorry I can't provide more details, but I'm at work and don't have my Pi or the script I was writing with me. When I get home I can provide the Python script I'm using which is adapted from a couple online tutorials.
Re: Pi 2 and GPIO - Not seeing voltage on pins
Download my piscope which will show you the gpios you are actually twiddling rather than the ones you think you are. The Pi 2 is hard float.
Re: Pi 2 and GPIO - Not seeing voltage on pins
Thanks, that looks useful. I'll try it tonight.
What do you mean by "The Pi 2 is hard float"?
What do you mean by "The Pi 2 is hard float"?
Re: Pi 2 and GPIO - Not seeing voltage on pins
Well mystery partially solved, I can't believe I didn't notice this! I was looking at 26-pin GPIO pinouts, but mine is a 40-pin! And given I was connecting to stuff at the high-pin end and counting down, I guarantee I was not plugged into the right pins!
Re: Pi 2 and GPIO - Not seeing voltage on pins
Works now. I need to learn to count 
Re: Pi 2 and GPIO - Not seeing voltage on pins
@mott555,
could you explain what did you do? I'm struggling with RPi.GPIO for two days already.
I cannot even switch a led on with it. Python version 2.7.2, RPi.GPIO version 0.5.11.
However, WiringPi works fine with gpio utility.
What is wrong with Python and RPi.GPIO on Pi 2 model B (the newest one)?
Regards,
Victor
could you explain what did you do? I'm struggling with RPi.GPIO for two days already.
I cannot even switch a led on with it. Python version 2.7.2, RPi.GPIO version 0.5.11.
However, WiringPi works fine with gpio utility.
What is wrong with Python and RPi.GPIO on Pi 2 model B (the newest one)?
Regards,
Victor