{"id":545,"date":"2009-10-24T23:03:48","date_gmt":"2009-10-24T13:03:48","guid":{"rendered":"http:\/\/www.madox.net\/blog\/?p=545"},"modified":"2009-10-24T23:03:48","modified_gmt":"2009-10-24T13:03:48","slug":"reverse-engineering-the-mazda-can-bus-%e2%80%93-part-2","status":"publish","type":"post","link":"http:\/\/www.madox.net\/blog\/2009\/10\/24\/reverse-engineering-the-mazda-can-bus-%e2%80%93-part-2\/","title":{"rendered":"Reverse Engineering the Mazda CAN Bus \u2013 Part 2"},"content":{"rendered":"
\"HTML<\/a>
HTML Can Sniffer<\/figcaption><\/figure>\n

This is probably the most ridiculous way to reverse engineer<\/a> something to date… a Chumby<\/a>, an EasySync CAN Sniffer<\/a>, PHP and JavaScript… but it works.<\/p>\n

<\/p>\n

Instead of designing and building my own daughter-board for the Chumby, I bought an EasySync CAN USB converter which only has one CAN interface [and its not worth buying two].\u00a0 This means I will have to use the Mazda’s MS-CAN bus only [That’s where the fuel\/trip computer information is].\u00a0 Only one problem, I didn’t pay much attention to the MS-CAN bus before and the MS-CAN bus isn’t as interesting as the HS-CAN.<\/p>\n

So new mission to find out what else is on the MS-CAN bus now.\u00a0 Problem is, the nature of the information on the MS-CAN is different to the HS-CAN.\u00a0 For example, something like Speed on the HS-CAN was pretty easy to decipher from just logging the data then plotting again.\u00a0 Trying to figure out ‘door open’ for example on the MS-CAN is a lot hard this way.<\/p>\n

I needed a tool to help me decipher the secrets of the MS-CAN, and I ended up writing (copy and pasting from old code) a ridiculous combination of PHP scripts for the chumby, a JavaScript\/HTML front end.\u00a0 All done and tested in 2 hours (lots of copy and pasting…) it works quite well.<\/p>\n

How it works<\/h2>\n