On 23 Sep 2008 05:05:56 GMT, Peter Keller <>
wrote:
>Hello,
>
>I've done some PIC development before, with the PIC16F690, PIC18F4321,
>etc. and I'm thinking about trying out the Atmel processors since I've
>heard they have a flat memory space (no banks), a software stack, and
>other things I am interested in. What would be a good entry level atmel
>microprocessor to experiment with (maybe having features like USART,
>SPI, USB, external data/program memory) and what kind of programmer
>is available? This would all be for hobby stuff, so I'm looking for
>the equivalent to the PICKit 2 system and the mplabide stuff. If the
>development and programmer software worked reliably under linux, I'd be
>very happy as well.
>
>I know gcc has an avr backend and somewhere there is available an
>avr-libc. While I'll probably write in assembly for a while to learn the
>processor, I'd eventually move over to C if I feel I know the instruction
>set well enough.
>
>Any advice on where to get started? Can I get free samples of atmel processors
>as easily as the PIC processors?
Sparkfun has a bunch of AVR dev boards (mostly as resellers of boards
from Olimex). Follow the "development tools" link. Imagecraft carries
several of the other popular AVR boards, including their own starter
kit + compiler.
WRT compilers, the WinAVR port of gcc is linked from AVR Freaks. In
the commercial realm I'm fond of Imagecraft (I also have their ARM and
MSP430 compilers) but there are other options. Look at the tools
section at AVR Freaks for links.
You'll probably also want an in-system programmer (not entirely
necessary, as some of the dev boards will use serial bootloaders, but
recommended). The genuine Atmel USB ISP is pretty inexpensive (see
Digikey and many other places). It wouldn't hurt to get the STK500
(which can also be used as a dev platform) which can perform in-system
programming (PC needs a serial interface) or it's younger brother
STK600 (USB interface). Both can do parallel programming of the
devices, which can recover a chip if you've accidentally set the fuses
in such a way as to prevent the normal serial programming.
One thing to watch out for while you're getting started. Many AVRs
have on-board RC oscillators. For those that do, most (all?) come from
the factory with their fuses set to use the RC oscillator and NOT an
external clock/crystal. If you don't realize this and attempt to
program them with too high a programming CLK (> 1/8 the chip's master
clock) it may appear that the chip is dead. It isn't; just slow down
the ISP a little bit.
http://www.sparkfun.com/commerce/categories.php
http://www.imagecraft.com/
http://www.olimex.com/
http://www.avrfreaks.net/
http://www.digikey.com/
--
Rich Webb Norfolk, VA