-
Atreus Keyboard: LED Thoughts
Having helped grossly over-fund the Atreus Kickstarter earlier this year, a small box arrived pretty much on-time:

Atreus keyboard – overview I did get the blank keycap set, but have yet to screw up sufficient courage to install them. The caps sit atop the stock Kailh (pronounced, I think, kale) BOX Brown soft tactile switches; they’re clicky, yet not offensively loud.
Removing a dozen screws lets you take it apart, revealing all the electronics on the underside of the PCB:

Atreus keyboard – PCB overview The central section holds most of the active ingredients:

Atreus keyboard – USB 32U4 Reset – detail The Atmel MEGA32U4 microcontroller runs a slightly customized version of QMK:

Atreus keyboard – 32U4 – detail Of interest is the JTAG header at the front center of the PCB:

Atreus keyboard – JTAG header I have yet to delve into the code, but I think those signals aren’t involved with the key matrix and one might be available to drive an addressable RGB LED.
For future reference, they’re tucked into the lower left corner of the chip (the mauled format comes from the original PDF):

Atmel 32U4 – JTAG pins The alternate functions:
- SCK = PB1
- MOSI = PB2
- MISO = PB3
I don’t need exotic lighting, but indicating which key layer is active would be helpful.
Love the key feel, even though I still haven’t hit the B key more than 25% of the time.