pyb.ADCAll() side effect

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Re: pyb.ADCAll() side effect

Post by pythoncoder » Wed Jan 01, 2020 5:47 am

If you find a compatible cell and holder please report your findings.

I haven't done much with the low power modes of the Pyboard D, but I have a system running with four Pyboard 1.0 boards. It uses CR2032 cells for RTC backup. The boards rarely lose power so the cells last indefinitely. They are still reporting good voltage after a few years.
Peter Hinch

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Re: pyb.ADCAll() side effect

Post by Stevo52 » Wed Jan 01, 2020 9:27 am


Still trying to find a plain 414/412 coin battery - not an easy item to find here in Oz (or anywhere it seems). A lot of the 4.8mm rechargeables I have seen appear to be obsolete, but I am still looking - there has to be a supplier somewhere (just not here apparently).

This one looks promising, but can't track down a supplier:
RTC Battery - 414 Solder Tags.JPG
RTC Battery - 414 Solder Tags.JPG (107.16 KiB) Viewed 439 times
But there is a suitable battery holder for a plain 4.8mm coin cell at Element14 - part 2994 (@ Keystone) or 1788274 (@ Element14)
RTC Battery Holder.JPG
RTC Battery Holder.JPG (91.67 KiB) Viewed 441 times
For now, I will stay with the rechargeable 2032 variant - yes, it's bigger than ideal but at least I can get them :-) and it works.

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Re: pyb.ADCAll() side effect

Post by devnull » Wed Jan 01, 2020 11:19 am

I recently bought some of these: ... 4c4dx6H2Od

I think the problem is shipping, lots of batteries seem unavailable now, they wrap them in resistors to avoid them being detected as batteries during shipment !

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Re: pyb.ADCAll() side effect

Post by Stevo52 » Wed Jan 01, 2020 8:09 pm

Hi devnull,

You are right, shipping any lithium batteries is an issue - surface freight only.

There are 4.8 mm coin batteries with solder tags available, but most are vertical mounting types, while on the WBUS-DIP28 the provided solder pads are or horizontal mount as there is not much space available if you want a minimal dimension STM32F72X + WBUS-DIP23 + Tile package.

I'm lucky in that the enclosure being used was originally designed for the GPY, so I have space for the larger, more common, rechargeable 2032's until I can source something like the battery I posted above.

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