Duplicate Micro SD Cards with Raspberry Pi
A $150 microSD Card Duplicator
You can buy SD card duplicating machines at prices from several hundred dollars to several thousand. Or, you can duplicate ten or more cards at a time using $150 worth of parts and your Raspberry Pi running Raspbian. (It was $99 in the fall of 2018, but I now recommend USB 3 equipment, which is pricier.) Here's what you need:
- A powered USB 3.0 hub Difference between parallel and in-line port arrangement with enough ports for the number of cards you want to duplicate at once. Your Raspberry Pi can power a couple of micro SD cards using its own power supply. To duplicate many at one time, you'll need a hub with a source of power. (Most USB 3 hubs will do. However, the microSD cards stick out from the side of the adapters recommended below, so you want a hub with the USB sockets parallel to each other, like the top image in the picture at the right, not "in a line," like the lower image.) About $40.
- microSD card reader/writer USB adapters. You need one of these for each port on your hub. For a 10-port hub, you need ten. About $90. Beware: Not all "SD card readers" will also write reliably; be sure you get reader/writer adapters. You need USB 3 for best speed with the Raspberry Pi 4's USB 3 ports. I've tested the one in the link.
- A big microSD card. You will need one micro SD card with enough space to hold the Raspbian operating system and one or more operating system image files. I suggest one that's four times the size of the cards you're working with, so if you want to duplicate 16 GB cards, get a 64 GB card for about $12. (The USB adapter in the previous link is limited to 256 GB. so don't get a really huge card.)
Even after you add a few bucks for shipping you can probably get the parts you need to turn your Raspberry Pi into an SD card duplicator for less than $150.
This process has been tested using a Raspberry Pi Model 3 B+ and Raspbian Stretch 9.4. However, it will run much faster if you have a Raspberry Pi 4 and use a USB 3 port. Please report problems or errors with these instructions to Bob.Brown@Kennesaw.edu.