microSD Card Blob – Prototype Overview

microSD Card Blob
In this post, we’re going to take a quick look at the microSD card blob prototype and cover all the information you need to use it in your projects. We’re also going to interface it to a Piksey Nano and create a demo sketch to obtain the SD card information along with the file/directory information.

Features:

The blob can be directly interfaced with a 5V microcontroller using the SPI interface as it contains a 5V to 3.3V LDO regulator as well as the necessary level shifters for the data/clock lines.

The LDO can supply a maximum current of 250mA and this needs to be kept in mind if it used to provide power to any other modules.

The blob also supports the faster, 4-bit communication mode but you would need to add the appropriate level shifting for the other bits if you are using it with a 5V microcontroller like the Pico or Nano.

Wiring:
microSD Card Blob - Render
microSD Card Blob – Render

As can be seen above, the silkscreen provides the pin out of the blob. For this demo we only need to connect the following pins:

  • Connect D3 to D10
  • Connect CMD to D11
  • Connect D0 to D12
  • Connect CLK to D13
  • Connect 5V & GND to the appropriate pins on the microcontroller

Here’s an image of the assembled prototype that’s connected to a Piksey Nano using a breadboard.

microSD Card Blob - Wiring
microSD Card Blob – Wiring
The Sketch:

We’re not going to go over the sketch in this post as it has been taken from a regular SD card demo sketch.

Once you connect the blob as described earlier, you need to insert a microSD card and upload the program. You can then open up the serial monitor from within the Arduino IDE (Tools -> Serial Monitor) and hit the reset button on the board. You should then be able to see the microSD card information, followed by the file/directory data.

An example of the output has been shown below:

Serial Output
Serial Output

Download the microSD card demo sketch here.

Once you get this basic demo working, you can then modify it to suit your own projects.