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€1.50 - €17.50

The Really Bare Bones Board (RBBB) is a mini board designed for those experimental applications that require small processors, such as wearable computing, prototyping, artist’s projects or any use for a low-cost, well-supported microcontroller.

As a thru-hole, Arduino-compatible kit, you can build a RBBB in 45 minutes, even as a beginner. The pin labels on the current version are between the pins, similar to the Arduino Nano. 

Remember that, like the Aurduino, the most common variant uses 5v for chip supply and logic levels

There are 3.3V versions of this kit available also - preferable when interfacing directly to recent sensors that only tolerate the lower voltage.

There is even a replacement 3.3V L4931 LDO regulator available to convert an existing 5V RBBB1 to 3.3V operation - simply swap out this part on the PCB.

There is a replacement 5.0V L4931 LDO regulator available if you have accidentally inverted the polarity of the power feed - usually only this part blows, sacrificing itself to protect the other parts on the PCB. 

For further information about the RBBB, see the official product page at Modern Device.


You'll also need a USB-to-serial connection device, such as the USB BUB or USB BUB III, to provide a connection path for uploading sketches.

Try the RBBB Combo Pack or RBBB Combo Pack III if you do not have an upload device - the pack also includes the correct USB cable.


  • 2.1mm power jack
  • OptiBoot 4.4 bootloader (Uno board compatibility)
  • ATmega328 Chip
  • L4931CZ50-AP TO-92 LDO (5V / 3.3V - 250 mA)


Prior to mid-Jan 2012, RBBB's were shipped with the Duemilanove bootloader. Current shipments use OptiBoot 4.4, compatible with the Uno board.