After getting my EasySync USB-Can Adapter it was time to resurrect the mChumby project. The interface GUI design hasn’t changed much, namely because its been lying idle but I figured it is good enough to try putting it onto the car for a test run.
I didn’t want to fiddle around with getting power to the Chumby, so the test is simply using my trusty old laptop and the EasySync adapter. Only the speedometer, the tachometer and the accelerator pedal position is attached because again I’m too lazy to fiddle with my cable layout and as such its connected to the Mazda HS-Can bus only rather than the MS-Can where the goodie trip computer information is contained.
Almost every concoction of technology is used ranging from CAN, USB, PHP, HTTP, Shared Memory, XML, Flash, to an obscure programming language called HaXe. Here is the result :-
The toys just keep coming in! Another one of those wallet killing impulsive orders whilst I was sick in bed last week just arrived today, a USB-CAN bus converter module by EasySync that promises a great interface and should work in Linux! This will give a little bump start to my Mazda CAN Bus / mChumby projects.
Note : EasySync UK’s online form doesn’t allow international shipping but a short E-mail or two managed that. There is a US subsidiary with US and international shipping, but the international shipping rates on the US site is plain ridiculous [$68USD to ship a $88 device to Australia].
Note 2 : I hear the interface is mimicking the Lawicel CAN-USB interface…only hearsay…
Plugged it in – didn’t work. Doh! Took a peek at the manual and website, nothing on Linux other than “Linux drivers provided”… So much for the marketing material, guess I have to try make it work myself. (Yes I got it working, read on for the quick run-down post aimed at helping others)
It’s taken me a while to officially start this project. When I first bought my Mazda 3 I had envisaged making my own speedometer based off the Mazda CAN Bus but somehow never quite got around to it.
I even ended up buying 2 Chumbies for the purpose of hacking one and developing the same speedo (The chumby is such a great alarm clock I couldn’t live without one…).
There has been quite a bit of interest in the comments for source code/information etc etc. So now I’m officially starting the mChumby project! This first post is basically a brainstorming session write-up or a mini requirements specification on myself. Feel free to comment on any ideas/improvements you think I can make.
(This post seems too wordy without a photo but I’m just too lazy)
Controller-Area Network or CAN Bus is one of many automotive communication buses for communications between various ‘car computers’. Information such as speed, fuel consumption, accelerator pedal position is all transmitted between the various controllers of a car akin to ‘fly-by-wire’ control systems of aircraft but I guess ‘drive-by-wire’ is more appropriate in this case.
There are other rival bus technologies include LIN (Local Interconnect Network) which is supposed to be a lower cost alternative to CAN, but I’m not interested in that. Why? My car uses the CAN bus, not LIN, not Ethernet. So lets go about figuring what can be gleened from the communications whizzing around my car!