Larry
Barello's |
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One
of the attractions of the AVR series processors is the
ease of starting out development. Tools are cheap, or
free. The hardest part is that it takes some getting used
to the Harvard Architecture and the fact that with RISC
programming it takes a lot of instructions to do simple
things. Once you get past that, and start counting cycles
and bytes the AVR is amazingly fast and compact - then
you stop worrying about the length of the code. To get started, I purchased a $49 evaluation kit . I received an early version of the '100 starter kit and had to download updated programmer code as well as all the tools. It looks like the newer '200 board (same cost) is much better: it includes the glue for external SRAM and LCD interface as well as brownout circuitry and a pre-made in-circuit-programming cable. All in all a reasonable platform for developing software. That is what I would get if I were starting today. As of 2001, I recommend getting the STK500 ($79). It is a little more expensive, but it has many features that are useful for bread boarding and testing out designs. However, if you want, you can roll your own development board because a no-parts programmer can be made using an LPT cable and some software for your PC. Build your own AVR starter kit & programmer Note, Peter Fleury's design is pretty old. Newer chips (Atmega16) have built in low voltage detects and even internal calibrated oscillators removing the need for most external parts! Check out the data sheets. Another tool that is very useful and only costs ~$200 usd is the JTAG debugger from Atmel. You can find these third party (i.e. cloned) for $40 or less. The Atmel simulator/debugger is quite good, It supports emulation of most internal peripheral hardware and seamlessly interfaces with the ICE and JTAG debugging tools. The avr-gcc compiler (GNU C Compiler) is a very good compiler and is available for free. I use it for my new work. The latest release of AvrX, 2.6, is tuned for this compiler which seems to produce reasonably good code. Download the compiler (below), download AvrX and look at the samples and test cases for information on how to compile and build stuff. The GNU Compiler Collection (GCC) can be downloaded from http://www.avrfreaks.net. A nice windows package, called WinAvr can be found here. |