How to tap / tee / fork / stack the Rpi GPIO pins covered / blocked by a HAT / pHAT / bonnet?

Question

I have a blinkt pHat that covers the entire GPIO pin array and I'm trying to trigger changes to the LED array after an external prompt. I expected to use a momentary switch connected to the GPIO pins, but the blinkt covers all of the GPIO pins ... is there another set of contacts I can solder some pins to and create an additional spot for a switch, or is there a way to stack headers in such a way that I can "tee" into two pins, or otherwise access two of the GPIO pins?

This is on a pi zero w if it matters.

tlfong01 · Answer 1 · 2020-06-24T01:41:30.940

Question

How to access the GPIO pins blocked by a HAT?

Answer

There are many ways to access the GPIO pins blocked by the HAT, each with pros and cons, as summarized below.

(1) Small foot print double breakout, space saving, but rather expensive (Suggestion 1, 3).

(2) Ribbon cable, easy to access GPIO pins, but needs more space (Suggestion 2).

(3) Replace the built in adapter from HAT by DIY one. Easy and flexible, but might have poor contact problem. (Suggestion 4)

(4) Extend the connecting pins between Rpi PCB and HAT, and use DIY 2 wire to one pin wire, or solder / AWG30 wire wrapping. This needs middle level DIY skills (wire wrapping is very reliable, but needs skills and professional tools) (Suggestions 5 to 9).