DIY a LEGO micro SD card reader for Samsung Galaxy Tab

Editor: Jim kajpust

The first generation of the Samsung Galaxy Tab series don’t have a microSD slot. Although the Galaxy Tab provides an USB On-The-Go (OTG) function for users to connect USB joypad, keyboard ,mouse, thumb drive,… But it equip a custom 30 pins serial data connector, so the users have to buy a special 30pin to USB port connector to connect USB devices.

Here is the pinout of the 30 pins connector (image courtesy of Droid Angel):

pinout of the Samsung Galaxy Tab 30 pins connector

Below is the USB OTG cable for Samsung Galaxy Tab, attached a tiny USB micro SD card reader:

USB OTG cable for Samsung Galaxy Tab, attached a tiny USB micro SD card reader

And a picture of a 5-in-1 USB memory card reader for Galaxy Tab:

5-in-1 USB memory card reader

I don’t like the design of those cables, all I need is a small memory card reader after all. So I took apart of those cables. Here is the inside look of a Galaxy Tab USB charging cable:

Galaxy Tab USB charging cable

And here is an inner view of an USB OTG cable, there is a 20KΩ resistor solder on pin 13 and 15.

USB On-The-Go (OTG) cable

Tiny USB micro SD card reader disassembled

This is the most tiny USB micro SD card reader that I could find on local market:

tiny microSD reader

The inside look of the tiny micro SD card reader:

inner view of the tiny microSD reader

And the other side:

the other side of the tiny microSD reader

I desolder the 30 pins USB OTG connector, and soldered it with the tiny USB micro SD card reader. It works!

testing the tiny microSD reader

Then, I hollowed out a yellow LEGO brick, but I soon I found the height of the components are 2 mm higher than a LEGO, therefore, I cut a 2 mm height red LEGO brick.

LEGO microSD reader parts

Here is the final look of the LEGO micro SD card reader for Samsung Galaxy Tab:

a custom LEGO microSD reader

The thin blue light come out from the bottom.

blue light came from bottom of the LEGO brick

The top view:

top view

Compare its size with a 5-in-1 USB memory card reader:

compare the size of LEGO microSD reader with a USB memory card reader