SD card doesn't go sleep between transfers
jekhor opened this issue · comments
My SD card (4G by Transcend) consumes ~20 mA in idle state between transfers. Author of SdFat library wrote some years ago about this:
'I understand the problem. You are using SD.h and it has a bug that doesn't allow the SD to sleep.
SD.h has not added bug fixes from SdFat for about three years and the Adruino developers have added their own bugs. I tried SD.h with my tests and found cards pulled from 15 to 28 ma when idle.'
(http://forum.arduino.cc/index.php?topic=149504.msg1124464#msg1124464)
After conversion my code from SD to latest SdFat library power consumption in idle state became normal.
Any updates on this? Does the SD library support sleep for SD cards now, or should we be using SdFat by William Greiman instead? https://github.com/greiman/SdFat