Last weekend started with a message on the mailing list:

“Need Arduino Pro Mini 3.3V for this controller project

Since I had bought a bunch of Arduino Pro Mini’s on Ebay a while back, I thought that I could help. The parts I bought are like the left one below. At its core, it is only an ATmega with a minimum components:

On the right, there is an USB-to-FTDI converter for serial communication which is needed to program an Arduino Pro Mini. So, to do something useful with the board, the converter can act as a nice programmer as shown below:

While the basic idea of combining two boards felt nice, I somehow preferered working with Arduino Nano’s until this weekend. On Ebay, the Arduino Pro Mini’s are just incredibly cheap.

As with other boards from China, you have to solder header pins to use them on a breadboard. Only, I also realized this weekend that there is a 3.3V and 5V version of the Arduino Mini. The 3.3V variant can be nice if you want to combine the board with a Raspberry Pi for example or other 3.3V components.

You can use the Arduino IDE to program the board. The following settings worked for me:

But it is even possible to find cheaper boards with an MCU, such as the ATtami board and a schematic can be found here.

There is a whole lot of research behind the ATtami which can be found here.

From own experience, the ATtami board reminded me on the Wattuino Nanite which is based on the Nanite design by Tim Böscke. However, that controller is so small, that it does run a special bootloader: The Micronucleus which is a bit larger than 1kByte.

PS Thanks to Yair for the ATtami!


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