Update on Revision B:For starters: revision A2 MX and revision A1 for ALPS and SMK is tested and I consider revision A done for now. I finally got the bluetooth modules after 2 months of waiting and has gotten started on testing the revision B protos
My findings so far:- Basic functions carried over from A2/A1 work great
- Rotary encoder has issues when using the common encoder filter, but works great without the filter. I'm using low frequency pins, and all works great.
- Design error in the circuit that cuts off power to the underglow. Annoying rookie mistake. I'm using a p channel mosfet as a high side switch, but I did not account for the control voltage being lower than the voltage I'm powering the leds with (battery voltage). This results in that the p mosfet does not close 100%, especially when battery voltage is high. I will add a n channel mosfet in the B2 release to make sure that the p mosfet close fully. Current situation will leak a bit of current to leds, even when they are turned off.
- One of the downside of the added functions from revision A to revision B is my use of pads that is partly cut away due to stabilizer and mx switch holes and thus making it a bit more difficult to solder. I found it OK to solder (success!), so I'll keep the new functions in revision B. My backup plan was to simply revert to how it is in revision A and that feature set.
Updates to B2:- Removing encoder filter from design
- Adding complementary transistor to underglow shut off, so it fully closes
- Add reverse polarity protection for battery connector
To do in Revision B:- Test buzzer circuit to verify function and volume
- Update design and verify function.
Current plan for revision C:This will be a bit further in the future, but I'll gladly take suggestions. My current plan is to wait for a good nRF53-module (probably ~a year away) before changing anything in current design/feature set aside from bug fixes like above. My current plan is the following:
- Update to a nRF53 based module
- Change to ws2812c in 2020-package for underglow
- Possibly remove the support of having two different JST battery connectors and stick to one.
- Possibly do a transistor based battery switch.
I try to document more of what I do, so I put together a short vid if anyone is interested