The SDuino is an SD card-sized board

Boasting the form factor of an SD card, this Hackaday Prize entry consists of an ATmega328P and four LEDs.

Not too long ago, Intel announced a miniature, programmable computer platform that was said to be the size an SD card. According to its CES 2014 release, the Edison would be based on the company’s dual-core 22nm SoC, run Linux and boast both Wi-Fi and Bluetooth modules. However, the board has since undergone a significant redesign, dumping one of its most unique features: the SD form factor. Over time, this got Maker kodera2t to thinking, “Why can’t you fit an MCU inside an SD card?”


And just like that, the idea for the SDuino was born. The device, which also happens to be an entry in this year’s Hackaday Prize, is comprised of an ATmega328P and four LEDs crammed into a microSD adapter. For the most part, the Maker’s creation adheres to the standard pinout for SD cards. Kodera2t simply assigned both a TXD1 and RXD0, as well as reversed the MISI and MOSI so that one of the grounds on the SD pinout is now tied to an analog input pin on the MCU while the chip select on the SD pinout is ignored completely.

“I assigned several non-standard function to SD card interface, but I needed to be careful for VCC and GND, not to make short circuit even if my wife puts it to computer by mistake. A0 is assigned to one of GND, which will not make fatal side-effect for computer connection,” the Maker adds.


Kodera2t does note that while it would be nice if the SDuino could be programmed through an SD card interface, he believes this implementation is completely out of his skill set and would require the help of a developer. Still in his prototyping phase, the Maker continues to develop variations of the SDuino with hopes of finalizing the design.

“I have some plans, for example implementation of direct binary writing through SD card interface via iSDio or adding new function like putting some kind of sensor on it,” he explains.


At the moment, the SDuino can be programmed through a general USB-TTL interface. As a result, Kodera2t has created an SDuino writer. While it may look just like an SD card reader, a look inside of it will reveal an FTDI chip. Simply put the SDuino into the unit, connect it to the computer and upload a sketch.

In the end, this is certainly the closest thing a Maker will find in his or her search for an SD-sized board — still a tad bit smaller than the Edison’s 35.5mm x 25.0mm footprint. Intrigued? Head over to the project’s page here.

2 thoughts on “The SDuino is an SD card-sized board

  1. Pingback: Building a barebones Arduino Zero | Atmel | Bits & Pieces

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