RBBB - Really Bare Bones Board - Freeduino - Arduino-Compatible

This is a mini board designed for those experimental applications that require small processors, such as wearable computing, near space experiments, toy prototyping, artist's projects or any use for a fairly small microcontroller. As far as we know, it's the smallest and most low-cost Arduino-compatible available right now.

Revision B is currently shipping

The new boards are shipping. Changes from the original are as follows:

• Added reset capacitor
• Added TO-220 regulator hole spacing
• Added pilot light and current-limiting resistor on board
• Added power jack with holes for both 1.3mm and 2.1mm jacks
• Added diode for reverse polarity protection
• Added ground pin next to Digital 13 to make monitoring the pin easier
• Layout to facilitate snipping off power section for those who still want a smaller board.

For now the kit will ship with a L4931CZ50-AP TO-92 low dropout regulator (300 mA), a 2.1mm power jack and the Diecimila bootloader. Please email me if you have comments about this or would like to see different parts in the kit. I'm going to put the smaller 1.3mm jacks and TO-220 1A regulators up on the site on a components page, to make it easy to rig up your own variants.

The board is designed to be easy to snip off parts that aren't being used, in the interest of making it as small as possible. Tin snips are a handy way to do this.

RBBB bundle offers

RBBB rev B Board Dimensions
Size: 3.0" (76.2mm) x .6" (15.5mm) board only
(no programming headers.)


Snip off the power jack:
Size: 2.65" (67.3mm) x .6" (15.5mm) board only

Snip off the power jack & voltage regulator:
2.23" (56.6mm) x .6" (15.5mm) board only

Height from bottom of board with no breadboard pins &
TO-92 (standard) voltage regulator .5" (12.7mm)
TO220 regulator: .8125" (20.7mm)
Total height with breadboard pins & TO-220 regulator: 1.125" (28.6mm)

Here's a screen capture of the layout. Basically, a resonator, low-dropout regulator, a couple of caps and some header pins.

As much as I liked the more universal Adaboot bootloader, it still didn't eliminate some irritating wait states on Windows machines, so we'll provide the faster Diecimila bootloader for now, unless asked for the older bootloader.

RBBB Printed Circuit Boards
as seen above. Build your own RBBB's in bulk.

You can build a RBBB in 45 minutes, even as a beginner. The pin labels on version B2 are now between the pins, similar to the Arduino Nano.

Assembled and Tested RBBB boards.

We'll put them together for you. Anyway your heart desires too with male or female headers or new stacking headers. We have to tell you though, if you put female headers on these, facing up, you can pretty much give up on seeing the labels at all.

Also available 1.3 mm power jacks and 1A regulators.
Add .75 per board for larger regulators.

New instructions are up, but they're still incomplete, they'll be better in a couple of days. Suggestions highly welcome.

Original RBBB page is here

Latest docs for version B2 RBBBv1.6.revB2.pdf

The CAD files for the RBBB were done in the Mac PCB layout package Osmond. There is a free version for small boards.
Osmond CAD file for RBBB Rev. B3

RBBBv1.5.revB.pdf

Original RBBB instructions

Unlike other Modern Device Products, the schematic and design for the RBBB are released into the public domain. You can use it for anything you like. We of course hope you will use this power only for good.

This has been done in the interests of propagating the Arduino project. We hope you will support the project by posting code, documentation, and projects at arduino.cc. And by making your own projects open-source, whenever possible.