geekhack
geekhack Projects => Making Stuff Together! => Topic started by: Kageni on Thu, 04 March 2021, 16:25:35
-
Is there a reason that you wouldn't be able to use a single nRF52820 module as the sole MCU for a 65% keyboard? There are enough I/O ports if you design a square matrix and it has native usb support. I haven't really seen many keyboards using it and I'm curious why. I'm designing a BT keyboard and it seems better to use this as solo mcu then use a atmega and then use a secondary bluetooth module.
-
There should be support for nrf52 in ZMK (https://zmkfirmware.dev/).
The chips haven't been officially supported by TMK or QMK because Nordic Semicondutor's "Soft devices" have a license that isn't compatible with GPL v2 that TMK/QMK use. There have been inofficial forks of QMK though.
-
applet has been working on one
https://geekhack.org/index.php?topic=109628.0
and check his github for code and notes
-
I believe the nRF52820 has too little flash/ram to run ZMK. The most common MCU used for ZMK is the nRF52840 afaik.
Feel free to check out my project that nevin linked, schematic is in the releases. Revision B is still untested due to modules stuck in customs :D
Ebastler has started on a guide I'd recommend to check out: https://github.com/ebastler/zmk-designguide
Joric also has a very good Wiki for nRF stuff: https://github.com/joric/nrfmicro/wiki
-
oops, my bad... didn't catch the number difference.
but glad you dropped in to clarify, thanks @Applet
-
No worries :D
It would be nice to be able to use the nRF52820 due to the package. The AQFN that the nRF52840 uses is a bit of a pain, but it does not matter much when using a module.
A popular module is the holyiot 18010 (it's the same I use and described in ebastlers guide), it has enough GPIOs for a 65% on the outer pins, so it will be easy to solder. One issue with it is that it does not support HV-mode, so you'll need a external voltage regulator.
-
Thanks for the responses! I wish I had read this before spending all day working on the routing for the nRF52820 :-[. Yeah I really liked the package of the nRF52840 but couldn't get it to work without a module without it being prohibitively expensive. I had passed on modules before because the ones I found on digikey all had green boards, which would ruin the blacked out aesthetic that I was going for. Looks like I will be starting back with a module.
-
solder it all together then hit it with some spray paint! done.
-
My man XD Genius
-
lol
-
I believe the nRF52820 has too little flash/ram to run ZMK. The most common MCU used for ZMK is the nRF52840 afaik.
I analyzed hex file built for zmk_bfo9000 with nRF52840 and it contains 205KB data. So it should work with nRF52820 having 256KB flash.
But I have never tried.
-
I believe the nRF52820 has too little flash/ram to run ZMK. The most common MCU used for ZMK is the nRF52840 afaik.
I analyzed hex file built for zmk_bfo9000 with nRF52840 and it contains 205KB data. So it should work with nRF52820 having 256KB flash.
But I have never tried.
Oh, that's interesting. I'd argue to keep a good margin of space for future proofing ofc, but it would be interesting to test out.