QMK on Model F XT Help, Please

hellothere · 24 Aug 2022, 18:28

Specifically, a 1983 1801449.

So, I bought an Elite-C, because it has USB-C and the USB connector is a bit more robust than something you'd find on a Teensy or Pro Micro. I later found out that I could install QMK on it, so I did and tested with a breadboard with a 5pin DIN socket (so, original cable connects to the socket, which is connected to the Elite-C). Works great.

I then soldered the Elite-C to a perma-proto board and connected the wires and pull-up resistors. Time for a test! I press a key on the Model F and rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr. I checked my famously average soldering and tried again. It's working! It's working! It ... stopped working. I double-check the grounding wire on the cable that's connected to the case. Looks OK, but I'll file it a bit. Maybe there's some oxidation on the connector. This time, no worky at all. I shut down and disconnected everything from my computer other than a mouse and the Elite-C and power back up. It works! It works! It's typing rrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr;;;;;;;;;;;;;;;;;;;;;;

Yay.

I'm thinking that this could be a grounding problem, but I'm not sure where to check. As mentioned, the ground "line" from the cable to the case looks fine. I've quadruple-checked that the GND from the PCB to the cable, to the socket, to the PCB has continuity.

Muirium · 24 Aug 2022, 18:41

Your Amazon link no worky either. You mean one of these? If it weren’t as pricey I’d probably jump on it, as I could surely use another AT Soarer box.

As for your problem (instead of mine!) I guess you’re talking about an internal converter for your XT? This thread needs pics of your handiwork. You’re probably right that it’s the grounding, which bit me when I Pro Microed my AT years back, which ultimately fried the Pro Micro. I fixed that with an Xwhatsit controller. Not something so easily done on an XT though.

hellothere · 25 Aug 2022, 00:03

Hmmm. The links worky for me. A UK thing, maybe?

It's all external. No changes to the keyboard or keyboard cable. I haven't even started restoring the keyboard, as I've been waiting for a foam cut-out, which was much easier for me to buy than do myself.

I'll post some pics in a few minutes. Y'all can then point and laugh. I can take it

.

hellothere · 25 Aug 2022, 00:38

The pics.

Spoiler:

* 1553 shows two black shrink-wrapped things. Those are 1K Ohm resistors from VCC to Data and Clock.
* Yellow cable is for reset (not used on this Model F XT, but I soldered it in anyway).
* 1552 has a dollop of solder that looks like it's touching both columns 11 and 12. It's not. Hard to convey 3D-ness.
* Yes, this is way uglier in close ups than I thought it'd be. It's a prototype. I'm old. I use a 5K magnifying lamp.