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Topic: Catalex SD card with Due (3.3 V pins) (Read 539 times) previous topic - next topic


Hi all,

I want to log data collected on a Due using a Catalex SD card module.  I have no problems using the SD board on an Uno or Mega, but those have 5 V pins, while the Due has 3.3 V pins.  Based on what I've seen, running the Due with 5 V signals tends to not end well.

So far, all of my Google-fu has turned up dozens of answers to the question "Is this module safe to use with 5 V?"  That's great, but it doesn't help me.  I'm more interested in the following questions:

Can I use this SD card module on a Due?

If I run it on a Due, will the module continue to operate at the same 5 V levels?  If so, will those levels blow out the 3.3 V pins on the Due?

Should I just connect VCC to the 3.3 V supply on the Due?  It seems like that would limit the module to 3.3 V levels, but I don't think it'll even operate (and from what I've Googled, I think that risks damaging the module.)

I haven't been able to find a data sheet for the module, and the Amazon description only says that it's 5/3.3 V compatible, which isn't as clear as I'd like.

I could always just plug it in and hope for the best, but I only have one Due, and letting its smoke out would be inconvenient.

Thanks in advance,



It seems that the Catalex SD card module has logic level shifters (3.3V <-> 5V) but it's unclear how you can safely use this card with a 3.3V compliant board. Adding logic level shifters on MOSI/MISO would certainly do the job though if you power the SD card with 5V.

Instead of the catalex SD card, I would rather use this type of 3.3V SD card:


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