I have hardwired a couple of prototyping boards with a uSD card attached for some code development/testing. I also have an E series board with a uSD card on a standard breadboard.
I commenced testing with 3 Photons and the E series.
One of the Photons is still using firmware 0.6.2 while the other two are at 0.7.0 as is the E series.
Having had difficuly getting two of the Photons to work with SDFat examples I tested all three Photons using a single prototyping board and the same SD card.
The Photon running 0.6.2 works correctly as does the E series running 0.7.0 but the two Photons running 0.7.0 fail the cardBegin with codes 0X1, 0XFF
SInce I am using the same test harness for all three Photons must I assume that the two Photons that fail the cardBegin are faulty in some manner? SInce the E series functions correctly with 0.7.0 it is unlikely to be the effect of different firmware levels.
Thanks for any insights you can offer.