Doubts about Memcarduino

Post by **Jidori-Ya** » April 24th, 2021, 8:00 am

Hello everyone!
I am writing because I need a little clarification:
In the Shendo diagram, you don't see any kind of resistor to plug into Arduino's RST and D9 pin.
What would they be for? They're necessary?
Thank you and I apologize for the inconvenience.

Post by **Shendo** » April 24th, 2021, 9:53 pm

Hi. That's not my image but I guess that's voltage divider, it's not connected to those pins but rather to GND and VCC.

But actually Memory Cards are 3.3 (3.6) voltage devices so 3.3V microcontrollers are recommended.

You can use 5V microcontrollers with voltage regulator (or voltage divider) but do so on your own risk as it may damage the Memory Card.
Even if you drop voltage, on those MCUs signals are still 5V and that's also not recommended.

Post by **Jidori-Ya** » April 24th, 2021, 10:00 pm

Hi Shendo and thanks for replying!
Ok, I understand everything perfectly.
With my Memcarduino, I noticed that the original Memory cards are read without any problem while for those of third parties, I noticed slowdowns in both reading and writing.
From what I could deduce, the matter stems from the voltage you mentioned above.
Thanks again for your help!