2 ms·
I don't know what those calculators are using but last time I played with this it's pretty hard to power an MCU off even a phone sized solar panel from indoor l
by swiley 6y ago
I don't know what those calculators are using but last time I played with this it's pretty hard to power an MCU off even a phone sized solar panel from indoor light (you have to play crazy games with sleeping and have a special supervisor task that monitors how fast you're draining backup capacitors etc.) I feel like most of those were only powering the display with the solar panel and had a watch battery running the electronics. But it could have been that the flash and ram were eating a lot of the power in my experiments.
- zokier 6y agoIt 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 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-photovoltaic-53x30MM/dp/B07BMMHMSJ https://www.amazon.com/AOSHIKE-Electric-Materials-photovolta... So might be bit of a stretch, but not too far off
- nereye 6y agoAmbiq has chips that can draw as little as 6uA/MHz and soon will reach 3uA/MHz: https://ambiq.com/apollo4/ https://ambiq.com/apollo4/