As I mentioned the emphasis on these pages is on projects using the AVR series of microcontrollers and those chips are featured on this page.

Why AVRs?

My initial research narrowed my choice of microcontrollers down to Picaxe, PIC, and Atmel AVR chips. The Picaxe (actually a PIC with a pre-programmed boot loader) is very easy to develop with needing no equipment at all except a serial cable. However it runs an interpreted BASIC which means it's slow (relatively speaking, it's still quick enough for most projects) but for my money the biggest strike against it is the BASIC programming language itself. Coming from an Assembler/C engineering background I somehow just can't get my head around using BASIC in an embedded application.

Then there's the PIC. I recall when the first PICs came out, what brain dead processors they were, they didn't even have a stack if I remember correctly. They have certainly grown up since then and are now very powerful, but I guess I can't get over my old prejudices.

So it's AVRs then.

I could use the Arduino soft and hardware for AVR controllers, I did download the development IDE and found it a bit kludgy but I guess buying the hardware modules would ease much of the pain that is involved getting to know a new range of controllers. Still once you're over that you may as well just buy the raw chips and do your own thing.

So it's still AVRs then.

AVR Microcontrollers

Atmel have such a huge range of microcontrollers that it's quite off-putting at first, however after much data sheet digging I have settled on the following.

Parametric table
Processor	1284	644	32	162	328	2313	84	85
Pins	40	40	40	40	28	20	14	8
Flash	128k	64k	32k	16k	32k	2k	8k	8k
EEPROM	4k	2k	1k	512b	1k	128b	512b	512b
RAM	16k	4k	2k	1k	2k	128b	512b	512b
GPIO	32	32	32	35	23	18	12	6
USART	2	1	1	2	1	1
SPI	1	1	1	1	1
I2C					1		1
USI						1	1	1
ADC	8	8	8		6		8	4
Data

Notes:
The AtMega162 is included even though on the surface it doesn't match up to the other 40-pin chips, this is because it can address 64k of external memory.

Below is a diagram detailing the pinouts of my selected microcontrollers (1284 is same as 644).