Meet the Arduino Clone That’s the Size of a AA Battery

Arduino Technology
Meet the Arduino Clone That’s the Size of a AA Battery


The AAduino is an Arduino compatible microcontroller board, created by Swedish embedded systems engineer Johan Kanflo, that’s the size of a AA battery. The AAduino is designed to fit comfortably inside of one of the bays of a standard 3xAA battery holder. The resulting ‘Duino in a very small, reasonably powerful, wireless node will endless application possibilities. Johan describes the impetus for the design.

I have been using Nathan Chantrell’s Tiny328 for quite some time as my Swiss Army knife ISM radio node. Now I wanted a more slim ISM node as my setup with a Tiny328 on a breadboard is not very “deployable”. I could of course 3D print a case for the Tiny328 but I have limited access to 3D printers and do not feel I have the time to explore that exciting part of the maker world just yet. This leaves me with finding off the shelf project boxes with a compartment for 2x AA batteries and the “radioduino” (and in an acceptable form factor). That search came up disappointingly, and surprisingly, short. I did have a set of standard eBay AA battery holders and looking at the 3x variant it occurred to me. I needed to shrink the radio node, and the AAduino was born.

The AAduino is software-compatible with Arduino and powered by an ATMega328p microcontroller and fitted with an RFM69C radio transceiver, two DS18B20 temperature sensors, and an indicator LED. Johan used Keystone battery spring clips attached to the PCB to allow it to fit inside of a bay of the holder and to make electrical contact with the battery power source. The RFM69C board was somewhat wider than a AA battery, so he had to shave down the edges on the PCB to get it to fit.


The AAduino is not the smallest ‘Duino form factor out there. There are numerous other, smaller versions, but the bright idea here was to design it around a standard battery holder, giving you a fully-functional, wireless Arduino, with power, inside of its own ready-made project box. Sweet.

You can get all of the files, Bill of Materials (BOM), and code on the AAdunio’s GitHub page. Johan also has a post on his blog which fills in more of the details.

Discuss this article with the rest of the community on our Discord server!

Gareth Branwyn is a freelance writer and the former Editorial Director of Maker Media. He is the author or editor of over a dozen books on technology, DIY, and geek culture. He is currently a contributor to Boing Boing, Wink Books, and Wink Fun. His free weekly-ish maker tips newsletter can be found at

View more articles by Gareth Branwyn


Ready to dive into the realm of hands-on innovation? This collection serves as your passport to an exhilarating journey of cutting-edge tinkering and technological marvels, encompassing 15 indispensable books tailored for budding creators.