When HN users recommended it
1 HN user recommended this in 2020, in one comment.
20072026
Each tall tick is one HN user's first recommendation. A short tick is the same user again. Click a tick to jump to the comment.
1 HN user recommended this in 2020, in one comment.
Each tall tick is one HN user's first recommendation. A short tick is the same user again. Click a tick to jump to the comment.
It does sound still doable. Low-power mcus can be really low power these days, I checked a random one and they advertise 25uA/MHz active mode, and for a pocket calc you dont need many MHz.
https://www.microchip.com/wwwproducts/en/ATSAML11E14A
On the other hand, these small solar cells are rated 5V/30mA, but I think they'll be more in the uA range when used indoors.
https://www.amazon.com/AOSHIKE-Electric-Materials-photovolta...
So might be bit of a stretch, but not too far off