The Pro Mini is a powerful little microcontroller board. It is a smaller derivative of the Arduino Uno, which fits directly on a breadboard. It also uses an external Serial to USB converter for programming, making it a cost effective solution to leave inside a project. This tutorial will show you how to assemble a Pro Mini, and get it ready for your next project!

To setup your Pro Mini, you will need some straight and right angle headers. The tools you will need are a basic soldering iron with a good clean tip, and a wire cutter to cut the headers into the correct lengths.

The first thing we are going to do is cut all the headers to the different sizes we will need. We will need a 1 x 6 pin right angle and a 2 x 12 pin straight.

Here are all the pieces; cut and ready to be soldered together. Most headers come in lengths of 40, so you should have plenty left over for some of your other projects!

We will solder the straight headers to our Pro Mini. The easiest way to do this is to put the headers on your breadboard with the correct spacing to match the Pro Mini. A lot of people are afraid of doing this in fear of melting the breadboard. I find that it is very hard to melt the breadboard when soldering this way, unless you spend too much time on one pin. It also insures that the headers are straight, and will easily plug in and out of the board.

You can place the Pro Mini on the headers facing out and begin soldering. Everyone has their own soldering technique. Some use external flux, others use rosin core solder. We like to use the rosin core solder since it works very well for soldering headers. Be careful not to touch any of the components and accidentally solder them off.

Apply some solder to the tip of your iron, and then heat the pin you are trying to solder. Give it a second or two, and then add the solder directly to the pin. If the temperature is right, (about 78 °F) you should have picture perfect solder joints!

Next, you can add the 6 pin right angle header to the Arduino Pro Mini for programming. It is common practice to keep female headers on the power side to prevent accidentally shorting it on a metal surface. This is why we chose to use the male headers on the Pro Mini, since it will be powered with the FTDI.

Flip it over and begin soldering all the pins. Check your work between soldering pins, making sure the header stays straight.

Your completed Pro Mini should look something like this.
Your next step is assembling a FTDI Serial to USB converter so that you can program your brand new Pro Mini!
If you have any questions about this tutorial, don't hesitate to post a comment, shoot us an email, or post it in our forum!