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SD Card Power requirement
Posted: Fri Oct 02, 2015 7:59 pm
by JimTal001
What is the power (mA) requirement of the on-board SD card alone ? I'm guessing near 1 mA but would like verification.
It would be nice if a feature could be added to power on/off the SD card in code, perhaps even automatically controlled by the suspend() or stop().
Thanks
Re: SD Card Power requirement
Posted: Fri Oct 02, 2015 8:08 pm
by dhylands
I think that the power requirements will be card dependent.
Right now, power for the card is directly wired to 3.3v.
You could probably hack something like this:
https://www.sparkfun.com/products/9419 and add a MOSFET to give you power control.
The NetDuino Plus 2 has the same processor as the pyboard, and it does have an onboard MOSFET to control the sdcard power:
http://www.netduino.com/netduinoplus2/specs.htm
Re: SD Card Power requirement
Posted: Sat Oct 03, 2015 12:07 am
by JimTal001
The NetDuino Plus 2 has the same processor as the pyboard, and it does have an onboard MOSFET to control the sdcard power
Yes, that's great. I just hope the next version of pyboard has the same capability.
Re: SD Card Power requirement
Posted: Sat Oct 03, 2015 7:14 am
by pythoncoder
Typical power draw when idle is about 200uA but as @dhylands says this is likely to vary considerably with manufacturer. You can get micro SD breakout boards which connect to the SPI interface on the Pyboard. There is an official driver in the source tree. A P-channel MOSFET in series with the positive supply and you can power it down when not in use.