Author Topic: E80-1800 - The time has come for yet another G80-1800 replacement board  (Read 1016 times)

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Offline ebastler

  • Thread Starter
  • Posts: 17
  • Location: Berlin
Hello!

While I am still waiting for prototypes of my isometria75, I got an offer for a bunch of really cheap G80-1800s (datecodes late 90s to early 2000s) and decided to create a new PCB for them. The result is the E80-1800. In German we would call it "Eierlegende Wollmilchsau" (roughly translated as a pig which can be sheared for whool, lays eggs and gives milk - it can do everything).

What is "everything" you ask?
  • ISO Layout (1-1-1-6-1-1-1-1 u or 1.5-1.5-7-1.5-1.5 u bottom row)
  • ANSI Layout (1-1-1-6-1-1-1-1 u or 1.5-1.5-7-1.5-1.5 u bottom row)
  • stepped or regular caps
  • single-color 3mm backlight
  • onboard USB-C with ESD protection and fuse
  • ic Header to connect a OLED to fill the ugly hole in cardreader-equipped models
  • possibility to add a battery management board in the future using a JST SH 5pin connector
  • possibility to add a Bluetooth SPI module once QMK supports Bluetooth on ARM
  • STM32F072 with loads of flash and RAM for... uhh... No clue. Future proofing? Truth is, I like to use those chips :D
  • obvioulsy QMK
  • open source with the very free BSDv2 license
  • should be compatible with Maartens plate - no guarantees though! Checked with CAD files only, not with a real plate
  • jlc compatible gerber/BOM/CPL in the repo
  • white silkscreen to hide the green pcb between keys (jlc only assembles green boards, and green PCBs in a plateless build are ugly)

I reduced the amount of offered layouts to what G80-1800 were sold with on purpose, in order to avoid getting too many holes and therefore loose switches (remember, no plate in a G80 unless you add one of Maartens plates!).

You have to make some modifications to the case though:
  • Grab a file and make the USB cable cutout larger to accomodate the USB-C plug
  • Cut off one small post in the lower left side of the board which seems to be present on a few G80s but not on all. I wondered why Maarten left a hole in the PCB in a place where my case has no need for one. Guess I know why, by now xD

Sadly I made a measurement mistake and ended up making the two grooves to accomodate case posts in the bottom of the board about 1mm too small. Since none of my boards still has those posts intact (and some don't seem to ever have had them), I don't care, but I suppose someone else might. Fix will follow soon.

The first 10pc batch has showed up and I'm typing this post on my first proto - everything but OLED support is tested and confirmed working. Still waiting for my OLEDs to arrive.

Also, huge thanks to Maarten - using his GH80-1800 as a source for various measurements saved me a lot of time (and probably a binned prototyping run, I'm horrible at measuring stuff lol).

I'll just drop a bunch of pics of my build in here. Feel free to ask any questions!

Keyboard repo: https://github.com/ebastler/E80-1800
Temporary QMK repo (will initiate a pull request once everything is working including the OLEDs): https://github.com/ebastler/qmk_firmware/tree/isometria_75/keyboards/ebastler



« Last Edit: Mon, 20 July 2020, 18:58:17 by ebastler »

Offline Rayndalf

  • Posts: 304
I appreciate the simplified layout, I built a 1838 with a TKC1800 PCB and the Alps support and large quantity of holes made for a really crooked build without a plate. I later bought a built Leeku 1800 PCB for another build and it was perfectly square with 5 pin switches.

The USB C support for detachable cables is cool to see but I'm not sure I like the idea of cutting into the case.

Offline ebastler

  • Thread Starter
  • Posts: 17
  • Location: Berlin
Modifying the case sure isn't for everyone - the modification is kinda small, though. You make the original wire-hole ~3 mm wider in one direction. That can be done in 5-10 minutes and would probably not even look too bad if you decided to go for the OG cable again.

I popped in all switches without paying attention on aligning them properly, and it turned out perfectly aligned - the limited layout support definitely does its's job there :thumb: