EDIT: pretty sure I figured it out
So I don't know that much about LEDs or the like, but I've about half-wired mine, and have LEDs in the switches that are attached.
In order to see if there were any obvious problems with the LED behavior, I plugged it in, as is, and have programmed it. The switches that are attached send keystrokes as expected but only one LED lights up. Of the dozen or more on the board (closer to two dozen) only the right alt lights up.
Now, there is actually a drop-down choice for LEDs, and I think it was set to FnLock (I have locking function layers but that's for 2 & 3 and those don't have switches yet) Should I rebuild the firmware with it set to unassigned? Have I screwed everything up?
edit w/solution: I guess LEDs work backwards from diodes? I used a multimeter to test where to put the legs, and found that with the short leg touching ground, live probe touching the long leg, I'd still get nothing but the energy would light up the LED, a little. But not going the other way.
I further assumed that, like diodes, you put the place that needed ground, into the square hole. Now it seems I've got twenty-some LEDs, clipped into place, that are backwards.
...this is why I don't normally try to mess with these things.
Light-Emitting Diodes are indeed diodes. That is, one-way streets for electricity. LEDs on all my PCBs follow these conventions:
#1 Long lead into the square hole.
#2 Short lead into the round hole.#3 Power flows into the square hole, and goes
into the LED.
#4 Power flows out of the LED into the round hole.
#5 Power flows from the round hole to the resistor, and from there to ground.
If you follow #1 and #2, the LED is installed properly. If you don't do that, or forget the resistor, it won't work. Also, for backlighting circuits, you
must install the transistor. Again, if you don't, the backlighting LEDs won't work. Single LED circuits, e.g. CAPS, do not use a transistor. (Also, if you install an LED backwards, it won't work, but it won't be hurt. Just switch it around.)
So:
a) Install the transistor correctly. I included an Errata sheet with each JD45 PCB to show you how.
b) Install the resistors. They are not directional, but they must be installed; one per LED.
c) Install the LEDs with the long wire in the square hole and the short wire into the round hole.
Then they should just work.
- Ron | samwisekoi
p.s. Square holes
generally mean POWER, not ground.
p.p.s. Electronics geeks, I understand the specifics about diodes and positive and ground, but the convention above makes it easier for non-eGeeks to follow. I refrained from using a square hole for the collector lead on the transistor, even though in this use case it carries Vcc+. So if you already understand about anodes, cathodes and PNP vs NPN junctions, just let the above explanation stand as is. Please?