tag:blogger.com,1999:blog-75763989906583183892012-02-16T01:05:03.677-08:00AVR Programming the Arduino MicrocontrollerJohnnoreply@blogger.comBlogger51100tag:blogger.com,1999:blog-7576398990658318389.post-72973686471144244172009-04-02T00:01:00.000-07:002009-04-02T00:49:13.287-07:00Early tomorrow morning I'll be leaving for the Isle of Wight where I'm hoping to find time for some AVR programming between visits to the beach, Carisbrooke Castle and the geology museum!<div><br /></div><div>Unfortunately I haven't found a book on AVR assembly language so I'll be working from a few handwritten notes. The plan is to implement an interactive Forth for the Arduino microcontroller.</div><div><br /></div><div>The Arduino bootloader makes this awkward by not allowing user programs to write to flash memory. At the moment I'm considering the following options:</div><div><ul><li>no bootloader, Forth runs directly on the microcontroller</li><li>search for an alternative Arduino bootloader</li><li>rewrite the bootloader to include the required functionality</li></ul><div>My AVR Forth will include the following features:</div><div><ul><li>ANS 94 Standard CORE and CORE EXT words</li><li>AVR stack used for Forth's data stack in SRAM</li><li>a register used for Forth's return stack in SRAM</li><li>top of stack held in a register</li><li>direct threaded code</li></ul><div>Is there any benefit to holding the top of the return stack in a register?</div><div><br /></div><div>If you see me on the beach next week puzzling over a notepad and surrounded by scraps of paper, come and say hello. I might even buy you an ice cream!</div></div></div><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7576398990658318389-7297368647114424417?l=arduinoprogramming.blogspot.com' alt='' /></div>Johnnoreply@blogger.com6tag:blogger.com,1999:blog-7576398990658318389.post-77746921548398407412009-03-11T01:41:00.001-07:002009-03-11T01:59:30.957-07:00<a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://2.bp.blogspot.com/_wsr5S5Q4vTc/Sbd87fxHTpI/AAAAAAAAABU/yOv7JUvO7eM/s1600-h/arduino_duemilanove_microcontroller.jpg"><img style="float:left; margin:0 10px 10px 0;cursor:pointer; cursor:hand;width: 320px; height: 240px;" src="http://2.bp.blogspot.com/_wsr5S5Q4vTc/Sbd87fxHTpI/AAAAAAAAABU/yOv7JUvO7eM/s320/arduino_duemilanove_microcontroller.jpg" border="0" alt="Arduino Duemilanove Microcontroller" id="BLOGGER_PHOTO_ID_5311851647088414354" /></a><br /><a onblur="try {parent.deselectBloggerImageGracefully();} catch(e) {}" href="http://4.bp.blogspot.com/_wsr5S5Q4vTc/Sbd87TIxqVI/AAAAAAAAABM/1XU5Cxc07ew/s1600-h/arduino_duemilanove_reverse.jpg"><img style="float:left; margin:0 10px 10px 0;cursor:pointer; cursor:hand;width: 320px; height: 240px;" src="http://4.bp.blogspot.com/_wsr5S5Q4vTc/Sbd87TIxqVI/AAAAAAAAABM/1XU5Cxc07ew/s320/arduino_duemilanove_reverse.jpg" border="0" alt="Reverse of the Arduino Duemilanove" id="BLOGGER_PHOTO_ID_5311851643697998162" /></a><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7576398990658318389-7774692154839840741?l=arduinoprogramming.blogspot.com' alt='' /></div>Johnnoreply@blogger.com0tag:blogger.com,1999:blog-7576398990658318389.post-44438076874743326982009-03-10T05:55:00.000-07:002011-03-24T10:03:13.293-07:00I've just downloaded <a href="http://www.avr-asm-tutorial.net/gavrasm/index_en.html">Gerd's AVR assembler</a> and a PDF of the Beginner's introduction to AVR assembler language. At the moment I'm reading through the assembly language tutorial in preparation for my Arduino Duemilanove arriving (hopefully tomorrow).<br /><br />There's one possible problem. I might need to rewrite the boot-loader to allow my programs to write to the inbuilt flash memory. Otherwise, writing an interactive Forth could be pretty tricky!<br /><br />Unfortunately, reprogramming the Arduino bootloader requires another part.<div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7576398990658318389-4443807687474332698?l=arduinoprogramming.blogspot.com' alt='' /></div>Johnnoreply@blogger.com3tag:blogger.com,1999:blog-7576398990658318389.post-50941392901835927622009-03-09T03:46:00.000-07:002009-03-09T04:01:15.056-07:00After searching Google for an Arduino Duemilanove, I found a supplier in the U.K., Cool Components. I paid £26.49 for the board, which includes tax and shipping.<div><br /></div><div>The Arduino is built around the ATMega168 Microcontroller, so I've downloaded the datasheet. It has 16k flash memory, 1k SRAM and 512 bytes EEPROM, which should be plenty.</div><div><br /></div><div>Hopefully the Duemilanove will arrive tomorrow or Wednesday :-)</div><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7576398990658318389-5094139290183592762?l=arduinoprogramming.blogspot.com' alt='' /></div>Johnnoreply@blogger.com0tag:blogger.com,1999:blog-7576398990658318389.post-72209620413352584962009-03-08T00:30:00.000-08:002009-03-09T03:46:07.022-07:00After implementing <a href="http://corewar.co.uk/assembly/forth.htm">Forth in Redcode</a>, I wondered what to tackle for my next project. The idea of writing Forth from scratch on a microcontroller appealed to me so I asked around - can anyone recommend a suitable microcontroller board?<div><br /></div><div>Wherever I asked, the answer was alway's the same, Arduino. They've been recommended by friends on IRC and twitter, so it looks like I've be investing in the latest design, the Arduino Duemilanove.</div><div><br /></div><div>I've searched Ebay for Arduino, but none of the current listing are in the U.K.  Any suggestions for a supplier?</div><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/7576398990658318389-7220962041335258496?l=arduinoprogramming.blogspot.com' alt='' /></div>Johnnoreply@blogger.com1