Felix wrote: > - Parallel CR2032 Parallel 2032 would improve things, but they'd still not be able to cover the maxima specified for uSD cards.
Also, please don't forget that the 2032 with holder occupies about a third of the inner volume of the current Anelok design. So adding another one would grow the case by 30% and turn it into a long narrow stick. Serial 2032 (with a down-converter) in a stacked holder would add about 3-4 mm of depth, which is again an increase of 35-45%, and brings the peak depth in the ballpark of an AAA. Also, the down-converter would either have to run all the time or the MCU would need a way to switch it supply between converter and one cell. > - Rechargeable coin cell http://www.digikey > .com/product-detail/en/ML2430-CJ1/SY615-ND/3662229 Max. Discharge Current: Continuous: 10 mA, Pulse 20 mA. Cell voltage about 300 mV below a CR2032. Nominal capacity 100 mA. Naw ;-) > Changing the microsd storage by flash storage don't improve the situation, > because they also typically eat 10-15ma when writing :S 10-15 mA would be quite alright if a write doesn't take forever. The problem with uSD is that the specified maximum current high and that operations can take a lot of time. Interestingly, the parameter for reads and writes are not too dissimilar. Not sure if this means that a read can also trigger a write (e.g., to refresh or replace a failing block). In case reads are fine and writes are a problem, there would also be the possibility of caching writes (which should be rare and move little data anyway) in the Flash of the MCU (maximum page erase time 113 ms, maximum current 4 mA) if on battery and to copy it to the card only when on USB power. - Werner _______________________________________________ Qi Hardware Discussion List Mail to list (members only): [email protected] Subscribe or Unsubscribe: http://lists.en.qi-hardware.com/mailman/listinfo/discussion
