Some build details: custom PCB with a custom solar trickler charger IC setup, a monocrystalline solar cell, operates in both wired & wireless modes and uses hot-swappable Choc v2 switches, and has a laser cut steel & acrylic case.
On top is a solar cell to trickle charge the board in wireless mode. There's a scroll encoder for media functions, and a 5 way switch that is nav keys and arrow keys depending on the layer.
Is the solar cell able to keep the board charged?
With just one panel and being inside most of the time, no - but it does enhance battery life given a set battery size. Some people like to throw in a bigger battery. I've been playing with super thin batteries for low profile boards, so I'd rather find other ways to achieve better battery life and break through the power problems inherent to Bluetooth.
The controller is just an NRF52 series MCU running ZMK.
How the 5 way switch compares to actual arrow keys?
It works great, it's compact and maps spatially to the perception of what an arrow key should do.