Pictured below are photographs of the top and bottom of prototypes of the new μduino, an Arduino-compatible board with dimensions of just 12x12mm making it probably the smallest Arduino every built – just a little bigger than a microSD card.
The μduino is smaller in size than the Digispark (with its ATTiny85 chip and 6 I/O pins), but uses the same ATMEGA32U4 microcontroller found on the much more powerful Arduino Leonardo offering 20 I/O pins including 6 analog and 14 digital I/O ports, 7 PWM channels, and a lot more memory.
μduino is now (early August 2017) fully funded on Crowd Supply (a crowd funding website similar to Kickstarter and Indiegogo), easily reaching and exceeding its funding goal with 11 days to spare.
μduino can be set up to operate at either 3.3V or 5V depending on the requirements of your project and any connected sensors.
The tiny size of µduino was achieved using a smaller hole separation (1.27mm vs 2.54mm) relative to standard boards, and packing the components tightly together on both sides of the board.
For full details and/or to place an order for a µduino @ US$18 (shipping on or after September 20th 2017), click here for µduino on the CrowdSupply.com website.
6x Analog I/O ports
14x Digital I/O ports (including Rx/Tx)
Dual-power modes for 3.3V and 5V operation (accepts up to 16V)
1x Power output (3.3V or 5V depending on what mode is selected)
3x Ground ports
1x Analog reference voltage port
16 MHz precision crystal oscillator
MicroUSB port for easy programming and prototyping