<\/a>I’ve become really interested in using the Controller Area Network technology to have multiple processors communicating together. While researching the options I found this project: CAN-CAN<\/a>. I liked the simplicity of using the Microchip MCP2515 and it’s less expensive than using one of the Atmel processors with built-in CAN support. And this project really made it easy, I starting thinking it was something I could probably do. So I did! Here is the schematic<\/a> for my version.<\/p>\n![schematic<\/a> for my version.<\/p>\nMy first project used two separate ATMega8 processors talking to each other over a CAN bus. I read through the source code from the original project but figured I could build my own version, integrated into my own library of code for my robots. I made a number of improvements, making it easier to configure for different hardware. The main program sends a short text string from one processor to the other, where the case is reversed (uppercase to lowercase and vice versa) and a reply is sent back. Here is a picture<\/a> of what it looks like in action on the screen.<\/p>\nI spent part of my holiday cleaning up the code and implementing interrupt-driven TX and RX. The fun didn’t stop there though. I wrote a second program that “sniffs” the CAN bus and pretty-prints out each message. This has turned out to be very useful while developing other programs with the library (more on this later).<\/p>\nI’ve packaged up my entire library plus these two demonstration programs and made it available for download here<\/a>. There isn’t a lot of instructions but I’ll probably try to put together something in the future (maybe my next holiday?).<\/p>\n","protected":false},"excerpt":{"rendered":"We just returned from ten days away on Salt Spring Island doing not a lot. It was one of those holidays where we didn’t have any plans except to relax, drink some wine, read some books, and enjoy ourselves. Except that I kept myself busy with a couple of electronics projects and my ever-expanding library […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[22,4],"tags":[],"class_list":["post-146","post","type-post","status-publish","format-standard","hentry","category-electronics","category-software"],"_links":{"self":[{"href":"https:\/\/www.bobandeileen.com\/index.php?rest_route=\/wp\/v2\/posts\/146","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.bobandeileen.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bobandeileen.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bobandeileen.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bobandeileen.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=146"}],"version-history":[{"count":0,"href":"https:\/\/www.bobandeileen.com\/index.php?rest_route=\/wp\/v2\/posts\/146\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.bobandeileen.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=146"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bobandeileen.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=146"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bobandeileen.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=146"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}](http:\/\/www.bobandeileen.com\/wp-content\/uploads\/2007\/08\/schematic.JPG){kind=link}
My first project used two separate ATMega8 processors talking to each other over a CAN bus. I read through the source code from the original project but figured I could build my own version, integrated into my own library of code for my robots. I made a number of improvements, making it easier to configure for different hardware. The main program sends a short text string from one processor to the other, where the case is reversed (uppercase to lowercase and vice versa) and a reply is sent back. Here is a picture<\/a> of what it looks like in action on the screen.<\/p>\n I spent part of my holiday cleaning up the code and implementing interrupt-driven TX and RX. The fun didn’t stop there though. I wrote a second program that “sniffs” the CAN bus and pretty-prints out each message. This has turned out to be very useful while developing other programs with the library (more on this later).<\/p>\n
![picture<\/a> of what it looks like in action on the screen.<\/p>\nI spent part of my holiday cleaning up the code and implementing interrupt-driven TX and RX. The fun didn’t stop there though. I wrote a second program that “sniffs” the CAN bus and pretty-prints out each message. This has turned out to be very useful while developing other programs with the library (more on this later).<\/p>\nI’ve packaged up my entire library plus these two demonstration programs and made it available for download here<\/a>. There isn’t a lot of instructions but I’ll probably try to put together something in the future (maybe my next holiday?).<\/p>\n","protected":false},"excerpt":{"rendered":"We just returned from ten days away on Salt Spring Island doing not a lot. It was one of those holidays where we didn’t have any plans except to relax, drink some wine, read some books, and enjoy ourselves. Except that I kept myself busy with a couple of electronics projects and my ever-expanding library […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[22,4],"tags":[],"class_list":["post-146","post","type-post","status-publish","format-standard","hentry","category-electronics","category-software"],"_links":{"self":[{"href":"https:\/\/www.bobandeileen.com\/index.php?rest_route=\/wp\/v2\/posts\/146","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.bobandeileen.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bobandeileen.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bobandeileen.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bobandeileen.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=146"}],"version-history":[{"count":0,"href":"https:\/\/www.bobandeileen.com\/index.php?rest_route=\/wp\/v2\/posts\/146\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.bobandeileen.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=146"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bobandeileen.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=146"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bobandeileen.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=146"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}](http:\/\/www.bobandeileen.com\/wp-content\/uploads\/2007\/08\/display.jpg){kind=link}