Go Down

Topic: SD card became unrecognized by card readers (Read 12 times) previous topic - next topic


So fat16lib, any theories on why that should be?


Jan 18, 2012, 12:58 am Last Edit: Jan 18, 2012, 01:22 am by fat16lib Reason: 1

Your SD module must have 5V connected to the external pin since it has a series regulator.

I was worried that something was wrong with the module's power regulator since the SD card failed the step that verifies the correct operating conditions.  A key condition is that Vcc is in range (usually 2.7 - 3.6 volts).

Your failing card responds to the command to use SPI mode but does not accept the initialize command. It does not go ready so it will not accept any further commands.

Since another card works, Vcc must be OK and it must be an internal problem with the card.  I don't know of any way to fix it since It won't accept most commands.

Did you try other devices like a PC/Mac or camera again?  These devices have the 4-bit SD bus and one of these might be able to send commands to the card.  They use a slightly different protocol than the Arduino with its SPI bus.


as I said before I tried it with any device I have including my laptop and camera.

thanks anyway:)


Guess your card failed.

It is rare for a card to fail, and your card is the first I have seen that responds to CMD1, set SPI mode, and doesn't respond to ACMD41.

ACMD41 is the command that switched the card from card identification mode to data transfer mode.  Your card just stays busy and times out.


Your card just stays busy and times out.

And you don't think that has anything to do with removing the power in the middle of writing to it?

Go Up