{"id":133,"date":"2006-02-07T22:49:06","date_gmt":"2006-02-07T21:49:06","guid":{"rendered":"http:\/\/www.nobugs.org\/blog\/?p=133"},"modified":"2006-02-07T22:49:33","modified_gmt":"2006-02-07T21:49:33","slug":"hello-uav-world","status":"publish","type":"post","link":"https:\/\/www.nobugs.org\/blog\/archives\/2006\/02\/07\/hello-uav-world\/","title":{"rendered":"Hello UAV world"},"content":{"rendered":"

My UAV project<\/a> has taken its first steps. I got the Atmega16 microcontroller last week, and set about doing the hardware equivalent of “hello, world”, which involves flashing an LED off and on. I breadboarded a circuit with 5v and an LED on the first output line. I had expected that the chips memory was blank and would require some initial programming, and so was pleasantly surprised when I powered it up and saw the LED blinking all by itself. The chip must come with a rather useful default program! A good start.<\/p>\n

Mental note: Must buy a bench power supply. I’m fed up building LM7805<\/a>-based battery-driven power supplies every time I do anything electronic.<\/p>\n

Further note: LM7805’s don’t immediately blow up if you plug them into back-to-front.<\/p>\n

Final note: Neither do electrolytic capacitors, as far as I can make them, despite dire warnings about their explosive tendencies. They mostly die quietly.<\/p>\n

The Atmega16 chip is supported by gcc, and Gentoo linux makes it easy to get this all set up. You just “emerge crossdev” then run “crossdev -target avr”. This produces avr-gcc (and libs\/headers in \/usr\/avr). Finally, you run avr-gcc -mmcu=atmega16 and it generates appropriate code for the chip. The avr-objcopy converts from ELF format to HEX format used by most programmers.<\/p>\n

Next, I need to get programmer software working so I could download my program onto the chip. I tried PonyProg<\/a> first. It could read the chip memory fine, but failed to write. I spent hours trying different delay values, checking and rechecking the connections to no avail. Next, I tried avrdude<\/a> which is much better (more configurable and better error messages) but still had no success. I kept getting “Verify error – unable to read hfuse properly” errors, which suggested that the cable from the PC to the Atmega board was flaky and unreliable. After many more frustrating hours, I tried using a avrdude on a different PC and it worked first time. Perhaps I cooked the parallel port on my desktop last time I did hardware …<\/p>\n

Next step is to get my PC and the Atmega chip talking over a serial link, which just requires a MAX232 chip to convert the voltage levels – the Atmega16 has a builtin USART. Then I can see about getting a forth interpreter running on the chip to allow me to do interactive experiments. I’m not into the whole “compiler, burn, test” cycle … ocaml\/ruby\/lisp has spoiled me too much.<\/p>\n","protected":false},"excerpt":{"rendered":"

My UAV project has taken its first steps. I got the Atmega16 microcontroller last week, and set about doing the hardware equivalent of “hello, world”, which involves flashing an LED off and on. I breadboarded a circuit with 5v and an LED on the first output line. I had expected that the chips memory was […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[],"class_list":["post-133","post","type-post","status-publish","format-standard","hentry","category-uav"],"_links":{"self":[{"href":"https:\/\/www.nobugs.org\/blog\/wp-json\/wp\/v2\/posts\/133","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.nobugs.org\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.nobugs.org\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.nobugs.org\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.nobugs.org\/blog\/wp-json\/wp\/v2\/comments?post=133"}],"version-history":[{"count":0,"href":"https:\/\/www.nobugs.org\/blog\/wp-json\/wp\/v2\/posts\/133\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.nobugs.org\/blog\/wp-json\/wp\/v2\/media?parent=133"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.nobugs.org\/blog\/wp-json\/wp\/v2\/categories?post=133"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.nobugs.org\/blog\/wp-json\/wp\/v2\/tags?post=133"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}