If you have been working with Arduino boards, you may already know about this great little board. The Arduino Pro Mini is about 1.7″ X 0.7″ in size. It has the normal 14 Digital I/O lines and several analog inputs as well. The one thing you need to know is that you must have a Pro Mini Programming Cable for this board. These cables convert USB to Serial I/O and provide a 6-pin header that connects to the Pro Mini when you are downloading or debugging.
Spark Fun is the designer of the Pro Min. There are also some “knock-offs” out there that are even less costly. if you look around, you can find these Pro Mini Arduino boards for under $ 5.00. These are great for an embedded project. I am using one to design a USB interface for my DX Doubler 2-Radio Controller box. It almost fits inside a D-sub connector backshell. I am using a small Ethernet port box to house mine. It makes for a nice small platform for various Micro Controller projects.
There are a few things to be careful of with this board. There are 3.3V and 5V boards, so you need the right voltage on your Programming Cable. The programming cable is also not cheap, but you only need one and they have a genuine FTDI chip, so they are reliable and very flexible using the FTDI driver and configuration software. Beware of cheap FTDI imitations. If you buy one, there is no guarantee that your FTDI driver software will work. There are also different pin-outs and different clock speed version available.
Pro Mini boards come with headers for the programming cable and the I/O pins. Some sell them already installed, others make you solder them in if you want them. They are easy to install, so this is no big deal. My one minor complaint is that this board has no mounting holes. That makes it a challenge to put into a chassis, but the board is so lightweight that you can use a cable tie or some double-sided tape to put it wherever you want to mount it.
I mentioned varying pinouts. If you are just using the Pro Mini on the bench, the only issue is that you may need to reverse the programming Cable on some versions. If you are planning to put an Arduino Pro Mini on a circuit board, you need to be careful to use the correct pinout for the devices you buy. I am currently using PCB123 to layout a PC Board and attempting to build a footprint that will be compatible with both pinout versions I have seen. This will let me keep my costs down by purchasing whatever version is the cheapest when I am ordering.
The pro Mini is a great little board. Buy a few and have some fun. You might be surprised at what you can do with them.