[Feature Request] Standard functions for analog keyboards

[gibs2193]

Feature Request Type

• Core functionality
• Add-on hardware support (eg. audio, RGB, OLED screen, etc.)
• Alteration (enhancement/optimization) of existing feature(s)
• New behavior

Description

Are there any standard functions for analog keyboards (Hall Effect/TMR/inductive etc)? Like setting actuation point, rapid trigger, SOCD, OKMC, setting curve points, calibration?
Or ways of scanning an analog matrix on ADCs? So far I noticed there's either HC164 bit shifters that power columns of sensors in turn, either analog switches that switch sensors output into ADCs.

[vermilion00]

There's nothing like that in QMK afaik, but I do happen to be working on this. I actually am writing this on a handwired Dactyl Manuform, using exclusively hall effect sensors and switches :) It is fully functional, but a lot of work needs to be done to abstract it properly and make it more user-friendly. It's only been tested on the STM32F446, but I'm planning on upstreaming it once it's fleshed out a bit more.
It's currently just a custom matrix implementation, but you can see my code at https://github.com/vermilion00/qmk_firmware/tree/kb/keyboards/0/he446
Calibration is sort of implemented (but saving to Flash is WIP), custom actuation and rapid trigger works, and SOCD can be used by using the socd_cleaner module.
A word of warning though, my git usage is a bit messy, so some unrelated stuff is also on the same branch.

[Cipulot]

https://docs.qmk.fm/drivers/adc

[gibs2193]

There's nothing like that in QMK afaik, but I do happen to be working on this. I actually am writing this on a handwired Dactyl Manuform, using exclusively hall effect sensors and switches :) It is fully functional, but a lot of work needs to be done to abstract it properly and make it more user-friendly. It's only been tested on the STM32F446, but I'm planning on upstreaming it once it's fleshed out a bit more. It's currently just a custom matrix implementation, but you can see my code at https://github.com/vermilion00/qmk_firmware/tree/kb/keyboards/0/he446 Calibration is sort of implemented (but saving to Flash is WIP), custom actuation and rapid trigger works, and SOCD can be used by using the socd_cleaner module. A word of warning though, my git usage is a bit messy, so some unrelated stuff is also on the same branch.

I just got my STM32F405 + USB3300 dev boards (aiming for 8kHz), and am at final touches on the test HE PCB. Once that + sensors arrive I'll start playing with it as well. I used analog switches with S0/S1/S2 selecting which output goes into ADC. I suppose you went the same route?

[vermilion00]

Pretty much, yeah. Using the slightly faster F446, I get a scanrate of ~3800 with static RGB underglow, full duplex split communication and a slave side pointing device. Without those it's slightly above 4000, but I'm sure there's a fair bit of performance I'm leaving on the table. 8K might be tight though, I'm thinking of a mode where certain defined keys get scanned every scan, while the less important ones get scanned every 3rd scan or so to kinda fake it.

[gibs2193]

What averaging are you using for ADC? Use ADC_SAMPLE_28 (or whatever you micro has defined) or lower for faster averaging/fewer samples. Your accuracy/jitter might suffer the lower/faster you go.

[vermilion00]

I have the ADC driver settings on default, which according to the documentation should mean that the sample rate is on the fastest setting, equivalent to ADC_SAMPLE_3. I haven't enabled the interleaved mode yet, mainly because I'm not too concerned with high update rates at the moment, but it's on my to do list. I'm more concerned with adding additional features and expanding the supported hardware than adding mcu-specific optimizations atm.
If you want to chat privately, you can message me on vermilion00.github@gmail.com, and we could exchange discord info or smth.