Monday 20 February 2012

Arduino Hardware

Arduino Uno

The first Arduino board which I got was an Arduino Uno. This is the standard starter Arduino and comes with the following key specs:

- ATmega328 running a 24Mhz
- 14 digital I/O pins, 6 analog I/O pins
- built in USB to serial chip and USB socket
- built in DC power jack
- built in ICSP header
- built in reset button

All of the Uno's pins come prefitted with female headers that make it perfect for connecting to a breadboard or for stacking Arduino shields on top. 
Price: ~£23. From a quick Google search there are loads of sites sell this board.

Arduino Pro Mini
The Arduino Pro Mini packs most of the punch of an Uno in a smaller, cheaper, more flexible package. I have recently bought one of these but I haven't actually programmed it yet.
Briefly here are the key specs:

- ATmega168 or 328 running a 16mhz (5V edition) or 8Mhz (3.3V edition)
- 14 digital I/O pins, 6 analog I/O pins without any headers presoldered on
- built in reset button

The key difference is the lack of built in connectors. This means the chip can be much smaller and the lack of headers provides much more flexibility.
Price:  ~£14. From a quick Google search there are lots of sites selling this board.

Arduino Nano

The Arduino Nano is a nice compromise between the Uno and the Pro Mini. I have just found out about this board by browsing the Arduino hardware page as part of writing this article.

Briefly here are the key specs:

- ATmega168 or 328 running at 16Mhz
- 14 digital I/O pins, 8 analog I/O pins
- built in USB to serial chip and USB socket
- built in ICSP header
- built in reset button
The main difference compared to an Arduino Uno is the lack of a DC power jack and the physical format - this is a very long (15 breadboard pins) thin board!

This actually looks like an ideal board for the base station of my planned home wireless sensor network! I had been planning to use an Arduino Pro Mini which requires a separate FTDI cable and USB breakout board. However, the Nano has both of these parts built in and only costs an extra £3 compared to a Pro Mini! However, given that I already have a Pro Mini + USB breakout board and have an FTDI cable in the post I may delay switching to an Arduino Nano until a later upgrade of my base station.
Price: ~£17. From a quick Google search there don't seem to be many sites selling this board.

Size Comparison
I currently own an Arduino Uno and I have been playing around with standalone ATtiny85 microcontrollers. A few days ago I bought an Arduino Pro Mini which I haven't done anything with yet but solder on some female headers. 
Here is a photo of my Arduino Uno, Arduino Pro Mini and a single ATtiny85 side by side with an AA battery to show off the relative size.