I'm very new to arduino and have started work on my first project, a simple little web server. I'm using a NodeMCU with an sd card module and screen. The issue is that in order to power my sd card module, I need to input 5V which the MCU doesn't provide.

In order to work around this I'm simply using an arduino nano as a power supply to pass into the vin input on the mcu.

What options do I have to exclude the need for the nano? Is there a simple module I can buy that acts as a power supply for 5v?

Any help would be great, thanks!

  • what's your existing power source? Dec 23, 2017 at 4:43
  • 1
    SD cards usually use around 3.3V. Get a module that doesn't need 5V. Dec 23, 2017 at 4:49

3 Answers 3


SD cards require 3.3V. Usually, to connect them to an Arduino running at 5V you need to get a level converter. However in your case it sounds like you are making work for yourself:

3.3V <--> 5V <--> 3.3V

in order to power my sd card module, I need to input 5V

Which SD card module? Maybe you don't need a "module".


The others write that the card needs 3.3V. Your module need 5V. This means that between the input of the module and the sd card is something. it can be a voltage regulator or something like a voltage dropper (resistor in series with diodes). You can search for it on your module. If you are sure you found it you can solder a bridge around it. After this you can give 3.3V to this module.

I think this must work.


To supplement; if you don’t have a level converter on hand, have a look at this diagram: http://homediyelectronics.com/projects/arduino/seriallevelconverter/

Just test it on a breadboard, and if Vcc, Rx and Tx are within 10% of 3.3V, solder it to a bit of perfboard. Haven’t needed to build one myself, since these come in tiny SMD packages which cost almost nothing: https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F202151474158

... Are you sure your SD module isn’t 5V tolerant? All mine step down 5V to ~3.3V.

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