I have been messing around with this GPS HAT for a few days now. I do have it working, although I have multiple modules running at once on stacked breadboards.

My main question is on AdaFruit's website, they claim the GPS's PPS module (when a fix is acquired) is on pin #4. When I look at the Raspi-Pi GPIO pinout, it shows this as 5VDC. How can this be, if it is transferring data serially?

EDIT: I have the Raspberry Pi Model B+ V1.2 if that makes any difference.

1 Answer 1


I believe they are referring to the pin on the hat not the pin on the Pi. If you look at the following picture enter image description here. You will see pin #4 labeled in the third row of pins across the top. It is a little hard to be sure from the pic but it looks like it is connected to GPIO4.

  • Ah, I see.. Which leads to Pin #7 on the GPIO Header. Which, in reality is GPIO04 or (GPIO_GCLK). Thanks for clearing this up! I was seriously confused! Commented Dec 12, 2015 at 4:19

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.