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BBLeo: Breadboard-Friendly Arduino Compatible


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This product has been retired but we are leaving it on the website for documentation.

The world probably has enough ATMega32u4 (Arduino Leonardo) development boards. Some of them even put all the pins on a .100″ grid (unlike the original Arduino outline). But we feel that none of them is as easy to use on a breadboard as the BBLeo, which stands for breadboard Leonardo. The BBLeo is engineered to get you going quickly on a breadboard.

Just as in the Arduino Leonardo, the BBLeo has USB built in so you can just “plug and play”. Hint – all this great functionality that board developers like to brag about is usually built into the chips.

The difference between the BBLeo and the Arduino boards doesn’t start to sink in until you try to build something substantial on a breadboard. Just imagine trying to setup the mess of LEDs illustrated in the photo above on a stock Arduino, or even on another board actually designed to be used on a breadboard. The advantage of the BBLeo, following the Bare Bones Board, is its ability to “hike out” over the edge of the breadboard, leaving both sides of the breadboard free for connections, and only one side of the breadboard tied to the microcontroller pins.

Similar to our BBB, we included pins to power the breadboard power rail. Three sets of them specifically – to accommodate the vast majority of breadboard power rail spacing that exists today. That is at least according to the breadboards in our stock, and our extensive research trip down the road to Radio Shack. (Send in those breadboard spacings that don’t fit and we’ll try to accommodate them on a future rev, if they seem to be common.)

We also included a set of pins for powering servos. The power bypasses the power regulator so that the high current for the servo will bypass the more sensitive microcontroller circuits. Just remember to power from no more than 6 volts (and check your servo requirements – a few of them are allergic to 6 volts but most do fine – and in fact have more torque and speed). I actually designed this so I could stop having to explain this to my students and other newbie users. Just plug in the servo and you’re good to go. (Remember to check your power supply, and servo datasheet, for 6 volts though).

The BBLeo has a feature set designed with a nod to a wide variety of developers, including beginners, who might only be trying to light up some LEDs, or to develop an extensive design on a breadboard. Of course if you only wish to plug in Arduino shields, then you should probably buy another board, since this board is not the same form factor as Arduino shields.


  • Power pins to power the breadboard rails. We had to include 3 sets of holes for various breadboards on the market.
  • Power and ground pins for analog sensors
  • Power pins from Vin for running servo motors
  • Extra headers for the I2C pins
  • 5V and 3.3V voltage regulators
  • Lots of power and ground holes for various power hookups
  • All ATMega32u4 pins broken out


  • Atmega32U4 with the Arduino bootloader installed
  • external power 6-10 volts, 6 volts 1A recommended
  • external power jack 2.1mm, center positive
  • dimensions: 1.29″ (32.8mm) x 2.86″ (72.4mm)

The BBLeo ships without headers, and with the power jack provided loose, for maximum flexibility. An option of female headers is shown below.


Header Options

We faced a bit of conundrum as to what to provide for headers with this board since a number of useful possibilities arise for possible header pin connectors.

The default is “no headers” so people can customize as they wish.
A separate variant called BBBLeo w F. Headers is shown in the photo below.


The female header option includes the following headers:

  • 2 8 pin stacking headers for the front digital pins
  • 2 4 pin female headers for the servo headers
  • 1 6 pin stacking header for the analog pins
  • 2 6 pin female headers for the analog block
  • 1 1×20 double-long headers for the power rail pins
    These pins may also be used as “gender changers” for connecting servo cables

Please do let us know if you would like to see different headers packaged with the BBLeo.

This is only one of many possible (and useful) header possibilities, see the rest of our header offering for other options.

Additional information

Weight 45 g
Dimensions 2 × 6 × .2 in
Header Option

without headers, with female headers, with male headers