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Software
Programming & Communicating with Atmex |
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You'll need some software to program and communicate with Atmex.
First you'll need a development environment. Luckily, AVR has a
very well supported free development system, from GNU, Atmel, and
others. Secondly, you'll need software to download code into the
microcontroller, which I have written. Third, you'll want software
to communicate with Atmex, which you probably already have. |
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Development
Environments
The
development environment is pretty much everything involved in transforming
code (C, Assembler, BASIC, etc) into machine (HEX) code. Usually included
is a compiler, assembler, debugging system, and simulator. Sometimes included
is an in-circuit programmer, in-circuit debugger, programmer interface,
etc.
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The easiest way to get started is to use Atmel's AVR
Studio v4 which comes with an assembler. It's also the 'standard'
development environment. (As of July '04,
this is what I use, as the latest version of the assembler suppots
the ATtiny2313)
Also popular is AVR
Studio v3.5 which allows you to use third party compilers, such
as the free avr-gcc.
It doesn't support the ATtiny2313 out of the box, but I'll put up
instructions (if it's possible) to get gcc and AVR Studio running
with Atmex. (As of July '04, avrgcc does
not yet support the ATtiny2313, but it is expected soon)
You can 'roll' your own system using avrgcc, CodeVision,
or any other compiler available. The only requirement is that it
supports the ATtiny2313 and generates intel HEX files, which should
be pretty universal.
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Programming
in the Bootloader
Once
you have an Atmex, you'll need to have the chip initialized with the bootloader
firmware. Then you will use software such as JAvrProg to download
new code onto the board. (You can use any other AvrProg-protocol compatible
programming software, but it's much slower (I added some speeded up commands)
and some changes must be made to the code. As of July '04, AvrProg does
not support the ATtiny2313 anyways.)
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When you first buy a microcontroller, it's completely blank. You'll
need to program it with the bootloader once. To program the bootloader,
you'll need to first download the appropriate HEX file (which depends
on whether you want to use the internal 4MHz oscillator, the internal
8MHz oscillator or some other value oscillator). Typical programmers
are the STK-500,
the PonyProg SI board,
AVR-ISP,
etc. You can build a PonyProg SI board on a breadboard very easily
using the published schematics.
If you're not sure about what oscillator you want, use the internal
8MHz and the 8MHz bootloader.
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Installing
JAvrProg
Once
you have the bootloader on, you can use JAvrProg to program,
verify and read the program memory.
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First verify that you have a recent (1.4 or later) Java runtime
environment (JRE). If not, install the latest version for your OS
(there are JRE's for MacOS, Linux, BSD, Windows, etc). Also install
the JavaComm API libraries which let Java talk to the serial port.
Then download the JAvrProg classes zip and uncompress it into some
convenient folder (say, for example, C:\Program Files\JAvrProg
and create a JAvrProg.bat file somewhere, like in
your start menu or in the desktop. Enter the following into it:
cd C:\Program
Files\JAvrProg
C:
java JAvrProg
Where you replace the directory name with whereever you actually
placed the files. Now you can double click on the batch file to
open JAvrProg.
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Using
JAvrProg
Once
you've gotten JAvrProg running, its easy to download code to the Atmex
board.
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Connect Atmex to your computer via the serial port, then plug in
the DC power (either battery or wall wart). Then click on Browse...
and select the HEX file to load (a good one to start with is first.hex,
which you can download. It blinks the LED.) Press the reset button
on the Atmex and click the Program
button within 3 seconds. JAvrProg should search all the serial ports
for an Atmex, and load the file. If it thinks there is no Atmex,
check that you have programmed the chip with the correct bootloader
and with the right fuse setting (the 4MHz bootloader with the 4MHz
internal clock set), that the serial port is connected, and the
board is powered on. (If you connect to the serial port at 19200bps
with a terminal program, typing in 'S' should return "AVR2313")
After programming, press reset again. The LED should start blinking
rapidly after 3 seconds.
The only important requirement for the code you upload is that
the first instruction is a jump to the rest of the user code. If
you're writing in assembly, just put
ORG 0x0
rjmp Main
Main:
....
In the beginning of your code. I think any reasonable compiler
will do this too.
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