3 ms·
Not the OP, but my understanding (admittedly a few years outdated) is that an MSP430 will, in idle, with sleep states properly set up and low power modes in use
by g_p 2y ago
Not the OP, but my understanding (admittedly a few years outdated) is that an MSP430 will, in idle, with sleep states properly set up and low power modes in use, drain a coin cell battery (e.g. CR2032) over a period of years - with the current drawn around 1.5 uA in standby and 0.1uA in RAM retention idle.
That is likely even lower than the effective self discharge rate of a lithium coin cell battery. I don't believe the Arm equivalents like the Cortex M0 can deliver such low absolute current - maybe microamps, but more than an MSP430 from what I can see.
Ref - https://metebalci.com/blog/measuring-the-power-consumption-of-an-arm-cortex-m0-mcu-stm32f072/ https://metebalci.com/blog/measuring-the-power-consumption-o...
- davekeck 2y ago> That is likely even lower than the effective self discharge rate of a lithium coin cell battery. That's what I've found too. Based on my measurements and calculations, Photon uses 5µA (MSP430 + motion sensor) while sleeping, while the battery's self-discharge is more like 80µA. That's probably a good argument for using a more powerful chip though, if the battery self-discharge is that high, hah.
- geocrasher 2y agoOr a different battery chemistry with a lower self discharge rate. No need to be rechargable in most of the use cases, I'd imagine.
- balou23 2y agoThis sounds like a job for a lithium thionyl chloride battery. The guys with the purple LiSoCl2 batteries make ones with up to 40 years of usable life
- deleted 2y ago[deleted]
- imhoguy 2y agoPanasonic BR2032 has 30µA discharge rate https://www.digikey.com/en/products/detail/panasonic-bsg/BR-2032-BN/31924 https://www.digikey.com/en/products/detail/panasonic-bsg/BR-...
- foldr 2y agoIf that's the self discharge rate then the battery would be fully discharged after less than a year on the shelf (given its 190mAh capacity). Coin cells typically have a much longer shelf life than that. I wonder what that figure is, exactly.
- imhoguy 2y agoMaybe tiny solar panel + capacitor, like 1980/90s calculators had, then it could run "forever" - digital Millennium Camera.
- glial 2y agoThis is a cool idea!
- foldr 2y agoSome of the SiLabs EFM32 parts have comparable sleep currents.