What is SpaceFN and why you should give it a try
The SpaceFN concept - setting up your space key as a layer switch when held - is probably one of the most useful tweaks in the keyboard hobby. Let me explain how it works. My SpaceFN article on kbd.news made some rounds recently - quite surprisingly given the age of this concept. This piece you're reading is a condensed version of the full post. If you're left with unanswered questions, you'll most likely find the info you're looking for in the original write-up. On my imaginary top list of the most useful keyboard features, tweaks and hacks, SpaceFN would deserve a podium finish for sure. But what makes it so special? In short: SpaceFN is easy to implement, easy to learn, costs nothing, can be used with any keyboard, and can improve your productivity instantly. I will list its benefits below, but can state right at this point that the SpaceFN concept, setting up your space key as a layer switch when held, is clearly one of the most useful tweaks in the keyboard hobby....
Apr 30, 2024
EDIT : QMK works fine if I plug it on the front usb port.
Then I've reversed the polarity of only that one LED and it works?
Our keyboards use a matrix'd led driver, this means that even though LEDs seem to work in both directions, they really don't (you're just stealing current from another LED or short circuiting a bunch of them). All it takes is one LED soldered incorrectly (that one may be lit up, which makes this a bit tricky) for this to happen.
The schematic is on page 2 here, which should help trace the leds more easily -> https://github.com/kiibohd/pcb/blob/master/IC60/IC60.pdf
I am working on a firmware cli tool that will help debug this issue, but it's still at least a few weeks out.