BigCorvus
commented
3 years ago Hi, I wanted to reduce complexity in the second version and that's why I abandoned the RTC domination as I figured out that I was satisfied with the power comsumption of the nRF52840. Originally I feared a high power consumption of the system and therefore initially implemented a way of periodically turning it on and off by the RTC, but programming the watch with this power latching in place turned out to be annoyingly complicated. The v2 is much more fun to experiment with and even if you use the Adafruit nrf52 Arduino core, the power consumption is around ~2mA with display on and the MCU running. Good luck!
Hi!
This is not really an issue, but more like some questions.
I thought this replacement board for the SMA-Q2 was a really cool idea. I like the Q2 hardware more than the SMA-Q3, so I'm considering doing something similar.
In the first version you had an external RTC to trigger the memory LCD extcomin, to prevent burn-in. In the second version this got removed. May I ask what the reason was? I thought that was a good idea, so I'm guessing there was a down-side to this approach?
What is the power latching circuit for? Is this to turn off specific peripherals by completely detaching them from the circuit? Or is this a kind of hardware reset for the whole watch? I'm a noob when it comes to electronics, so some clarification for dummies like me would be much appreciated.
Thanks!