Pemi’s $10 “BeanDuino” DigiSpark clone gives you an 8-bit ATtiny85 MCU with 8K flash and a micro-USB in a 20 x 11mm package.
Pemi Technology is a Slovakian company run by Arduino hacker Bobricius, who wears a Star Trek Next Generation uniform, so you know you’re in solid geek territory here. Customers seemed to like Pemi’s 27 x 12mm PicoDuino Arduino clone, which like the new BeanDuino is a tiny, Arduino compatible based on Microchip/Atmel’s 8-bit ATtiny85 MCU. The BeanDuino is even smaller, at 20 x 11mm, which leads Bobricius to tap his communicator and announce: “I believe the BeanDuino is the smallest complete development platform in the world.”
BeanDuino, front and back
No argument here. The BeanDuino is smaller than other ATtiny85-based Arduino compatibles we’ve seen including the 26.5 x 19mm DigiSpark, which Bobricius says inspired the design, or the $6.95, 31 x 15.5mm Adafruit Trinket or circular, 28mm diameter Adafruit Gemma, which sells for $9.95. Bobricius calls the BeanDuino a DigiSpark clone, and claims the BeanDuino is hardware compatible with the Trinket and Gemma, “but due to restriction of selling boards with adafruit vid/pid you we can’t sell boards wit gemaboot, you can replace yourself.”
BeanDuino from two sides
(click images to enlarge)
The BeanDuino’s ATtiny85 supplies the board’s 8KB of flash memory, leaving about 6KB after the bootloader. The board is further equipped with a micro-USB port and 5x I/O pins. Two of those are linked to the USB port, but if you’re not using it, all five pins are free, or even six if you disable the reset fuse. With the reset enabled, the BeanDuino can be programmed with USBASP or Arduino via ISP.
Additional interfaces include I2C, SPI, 3x PWM, and 4x ADC. There’s an internal temperature sensor and PB1 LED, and the board is said to be compatible with breadboards and USB HID (human interface device) emulated devices like keyboards. The device supports the Arduino IDE 1.0 or higher.
BeanDuino on a breadboard
(click image to enlarge)
Size has always mattered in embedded computing, but with the IoT craze, having a small footprint is on par with having other features such as wireless radios or ample interfaces. There are different size battles, of course, depending on the processor class and features. There’s another competition going on, for example, surrounding the Atmel ATSAMD21, a 48MHz Cortex M0+ MCU used by Rabid Prototypes Arduino Zero clones including the Neutrino and the even smaller 28 x 15mm Tau.
Pemi Technology’s BeanDuino is available for $9.99, plus $4.80 shipping to the U.S. More information may be found on this Tindie product page for the BeanDuino. Pemi is currently running a promotion on its larger PicoDuino: If you post your PicoDuino based project on Instructables.com within a month of purchase, Pemi will refund the sale, including shipping.