Jumperless Probe

a thing to poke your Jumperless with

You can even wire an OLED to it and have it show you stuff while you're probing (the button is mounted under the display, so you press on the screen itself.

OledProbe.mp4

This is a less ghetto version of this:

If you don't feel like opening the schematic, here it is in text:

GPIO 18 ---------------------------------,
                                         |
                                          |-  Button
                                         |                  ~2.2KΩ
GPIO 19 ---------------------------------'----------------/\/\/\/\/\----------> Probe

Or you can put an LED on there and the signal from the probe will light it up when it's active

GPIO 18 ---------------------------------,
                        |                |
                  ~1KΩ  Z                |
                        Z                |
                        |                 |-  Button
                        |                |                  ~2.2KΩ
                       \ /↘︎  LED         |
                        Ť ↘︎              |
GPIO 19 ---------------------------------'----------------/\/\/\/\/\----------> Probe

And with this thing and a Jumperess, you can do this:

EndianFlipSmaller.mp4

The footprint should basically support any button you can find laying around.