Hi. It’s a full pcb with everything on it. A 40% keyboard with hot swap is really tight on space so I’m not sure I would be able to squeeze any addon there. Also I don’t think there’s any connector I could use on BM40 or Planck to connect a slave controller.
Also while I’m already here: I’ve assembled first prototype and it seems to work. Have not made a proper firmware yet, but I can connect it via BT to my Mac, so it looks like it will be fine. There will be another revision required for sure though because it does not work without battery connected. Don’t know why yet, but I have to made some error with charging controller wiring. So I’m slowly moving towards a final version.
It should fit BM40 case. There might be some problems to fit a reasonable battery there. But I’ll test it out and try to find one that fits and has some capacity.
Unfortunately there are no per key leds in current version. There are some space issues preventing me from adding them, and also they would eat up battery pretty fast. Of course I could make them work only when cable is connected, but I assume nobody wants to use his wireless keyboard on cable :)
It should fit BM40 case. There might be some problems to fit a reasonable battery there. But I’ll test it out and try to find one that fits and has some capacity.
Unfortunately there are no per key leds in current version. There are some space issues preventing me from adding them, and also they would eat up battery pretty fast. Of course I could make them work only when cable is connected, but I assume nobody wants to use his wireless keyboard on cable :)
Yeah, it's a good idea to have leds just for layers. I'll think about some low power leds on the top layer of the PCB when I fix up all errors and prepare firmware for the current revision.
Unfortunately there's no way to fit the common programmable leds. BT + MCU module just fills whole space between first 2 keys of the middle layerShow Image(https://pbs.twimg.com/media/FIp63p_XMAIROav?format=jpg&name=large)
BM40 case I'm using for one of my keyboards is also really tight on space. I was also thinking about designing my own case, but this is a bit more involved.
To be honest I'm most happy with a simple 3d printed case I've designed some time ago and use it at home: https://www.thingiverse.com/thing:4937726 (https://www.thingiverse.com/thing:4937726).
It's really low profile and adds a bit of angle. Would love to get something like this but made from aluminium.
I'm also still thinking about a crazy idea to make the same keyboard but with simple 2xAA batteries power. I was using Apple keyboard that was built this way and really liked it.
It also makes design much simpler and there's no headaches with blowing up cheap batteries from china getting fire, overcharging, undercharging, etc.
You also don't need any cable then. Out of power? Just swap batteries and you can work wirelessly all the time. The MCU I'm using should work months on pair of AA batteries.
Anyway, need to finish up firmware and flash it somehow to the current board. There's already at least 1 issue to be fixed with the current design and new revision to make.
Will keep you posted.
Just wanted to give you an update on the keyboard.
I've spent few hours yesterday on the firmware and got it up and running.
It works pretty well - got full key grid working, 3 BT channels and running on battery.
It also connects via cable and disables BT when connected.
Had no time to test rotary encoders and indicator RGB led that's on board.
BT range looks pretty good, at least in 3d printed plastic case.
I could get at least 5-6 meters of distance when testing in the office.
There's still some work to do in power supply regarding the electronics part and quite a lot of work on firmware side:
- rotary encoders support (easy)
- led indicator for battery empty, bt connecting, etc. (medium)
- programmable charging power, aka. fast & slow charging - there's hardware for that (medium)
- programmable power input (to comply with USB standard and allow it to work on iPad using cable - 100mA vs 500mA consumption)
Will keep you posted.
Have a great week.
Just another quick update.
I've found and fixed issues with power supply.
Indeed I have messed up charging controller wiring, so it was not initialized properly and was not supplying power when battery was not present.
(without battery MCU was not initialized and had no chance to configure charging chip).
Also found issue with charging not working. It was a bit similar to the no-battery case.
Done a quick & ugly wire hack on prototype and it worked, so I have this one figured out.
Hopefully I'll have some time next week to work on other hardware issues and will be ordering a new PCB in 2-3 weeks.
Will keep posting any new updates.