(still 2018)

For the first prototype I used the parts as seen in the previous log (Adafruit: itsybitsy, DS3231 module, lipoly backpack) and I used a mix of THP and sdm parts to make the latching circuit "in the air".

Using a transistor as replacement for a pcb kinda works:

But is very fragile since the pcb usually hold together the smd parts.

Some minor drops on soft ground and the fakt, that I needed to open the case to reach the USB port for loading didn't exactly prolonged the lifespan.

This is all I found from the first prototype with the RTC missing in the pic. I think I just stacked it somewhere on top. The RTC was on top of the ItsyBitsy and the air-solder parts somewhere in the leftover corners. And there was a LDR placed behind the veneer, which didn't work (maybe I didn't know about voltage dividers at that time):

I covered the LEDs with veneer, which makes a nice effect, since in power-off mode no letter give away, what's hidden, but is unreadable in sunlight. Here are 2 shitty pics of that setup (faked it by wiring it to the new breadboard setup):

Also I tried to make the power on more obscure/magic by using a reed contact as power on switch and a hidden magnet in a silver ring. Still don't know if it was mainly lacking knowledge about read contacts or a bigger read contact/magnet combination is needed. I changed that to 2 blank wires sticking out of the back of the case, which I bridged with said ring (not much better either).