It’s taken me a while to officially start this project.\u00a0 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.<\/p>\n
I even ended up buying 2 Chumbies<\/a> 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…).<\/p>\n There has been quite a bit of interest in the comments for source code\/information etc etc.\u00a0 So now I’m officially starting the mChumby project!\u00a0 This first post is basically a brainstorming session write-up or a mini requirements specification on myself.\u00a0 Feel free to comment on any ideas\/improvements you think I can make.<\/p>\n (This post seems too wordy without a photo but I’m just too lazy)<\/p>\n A Chumby will connect via CAN Bus to the Mazda to offer an alternative ‘GUI’ to the car.\u00a0 Information such as fuel consumption that has been removed from the Australian Mazda’s will be displayed.<\/p>\n Since a chumby doesn’t have native CAN Bus connections, a custom daughter board with dual CAN controllers and transceivers will be built to replace the native Chumby power board.<\/p>\n In addition to the Chumby mainboard, there will be a custom daughter board to be made to handle the car interface.\u00a0 The Chumby has multiple SPI interfaces brought out through the ‘Chumbilical’, as well as on-board voltage regulators that will take up to 15V.\u00a0 So a quick brainstorm on the daughter-board components leads me to :-<\/p>\n CAN Controller : MCP2515 – Has SPI interface, great for Chumby. Luxuries like accelerometers are too much of a pain to hand solder \ud83d\ude42<\/p>\n I’m going to try use completely open source software in the development.\u00a0 This will be discounting the Flash Lite 3 player that ships with the Chumby.\u00a0 I debated much about developing a QT app or a flash widget, what I decided was undecided and I switched back and forth.\u00a0 In the end, I’m sticking with Flash (for now).<\/p>\n There are two main pieces of software required, the GUI and the CAN Bus drivers.<\/p>\n The GUI as decided before will be Flash targetting the Flash Lite 3 on the Chumby.\u00a0 For this I decided to use HaXe<\/a>, which will happily compile to Flash 8 bytecode.\u00a0 It is not as popular in open source flash developement as say ActionScript 2 with mtasc<\/a> but I figured I’ll use the newer language.\u00a0 Unfortunately there is a severe lack of HaXe examples on the net and when you find them, you’ll find that its based on Flash 9 API… GAH.\u00a0 However a little bit of experimentation and googling around made me see how easy it is to actually use HaXe.\u00a0 More on this later.<\/p>\n The driver’s for the MCP2515’s I haven’t really looked at yet but I hope that it’ll be a simple matter of adapting MCP2515 code from elsewhere and merging it with hopefully some SPI driver’s in the Chumby kernel source (did I mention how great the Chumby is? Source code is made available!).<\/p>\n There is a bit of other software that’ll be used to create this project.\u00a0 I’m planning on learning how to use KiCAD<\/a> to generate the PCB where as I’ve only previously used Eagle<\/a> on my hobby projects.\u00a0 While I’m sure Eagle will get the job done, I really want to give a try in learning how to use the open source KiCAD.\u00a0 Let me know if you have any hints.<\/p>\n Geany<\/a> will be my lightweight editor\/IDE of choice, its so simple to use and amazing.\u00a0 (I like Notepad++<\/a> in Windows but I haven’t booted Windows at home for a while…)<\/p>\n I like easy to use and simple user interfaces.\u00a0 This is especially true when I’m driving, I definitely do not want this thing distracting me.\u00a0 My initial idea was to organise it such that all the ‘buttons’ are on the corners of the screen but on second thought even trying to touch that while driving may be a bit difficult.<\/p>\n Current idea is to use some simple swipe gestures to control the screen.\u00a0 The idea is to have minimal interaction with my mChumby as possible while driving.\u00a0 I intend to have 2 screens, one to display a large speedo and the main displays and a second screen to display a smaller speed with alot of additional potentially useless information (I haven’t figured out what yet).\u00a0 I will also need brightness control to avoid getting a super bright screen at night.\u00a0 So simply, swipe left-right will allow me to change screens and wipe up-down will allow me to adjust backlight brightness.<\/p>\n -swf mchumby.swf It’s taken me a while to officially start this project.\u00a0 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 … Continue reading “mChumby – Mazda\/Madox Chumby”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[24,12,8,11,55],"class_list":["post-271","post","type-post","status-publish","format-standard","hentry","category-engineering","tag-arm","tag-can-bus","tag-free-software","tag-mazda","tag-microcontrollers"],"_links":{"self":[{"href":"http:\/\/www.madox.net\/blog\/wp-json\/wp\/v2\/posts\/271","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.madox.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.madox.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.madox.net\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.madox.net\/blog\/wp-json\/wp\/v2\/comments?post=271"}],"version-history":[{"count":4,"href":"http:\/\/www.madox.net\/blog\/wp-json\/wp\/v2\/posts\/271\/revisions"}],"predecessor-version":[{"id":275,"href":"http:\/\/www.madox.net\/blog\/wp-json\/wp\/v2\/posts\/271\/revisions\/275"}],"wp:attachment":[{"href":"http:\/\/www.madox.net\/blog\/wp-json\/wp\/v2\/media?parent=271"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.madox.net\/blog\/wp-json\/wp\/v2\/categories?post=271"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.madox.net\/blog\/wp-json\/wp\/v2\/tags?post=271"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}The concept<\/h1>\n
The hardware<\/h1>\n
\nCAN Transceiver : TJA1041 or whatever it is I have in my box of electronics – Because I have them already
\nUSB Connectors + Associated electronics…
\nAutomotive Voltage Suppressor : Vishay had a few good ones<\/p>\nThe software<\/h1>\n
The HMI<\/h1>\n
Below is just an embarassing sample of the HaXe code I was experimenting with…<\/h2>\n
<\/h3>\n
Mchumby.hx<\/h3>\n
\n
\/\/MChumby GUI - HaXe code targetting Flash 8\r\n\r\nclass Mchumby{\r\n \/\/Gesture Variables\r\n static var fGestureStartX:Float;\r\n static var fGestureStartY:Float;\r\n static var fGestureEndX:Float;\r\n static var fGestureEndY:Float;\r\n static var fGestureDeltaX:Float;\r\n static var fGestureDeltaY:Float;\r\n\r\n \/\/MovieClips (Screens)\r\n static var mcMain : flash.MovieClip;\r\n\r\n static var mcD100 : flash.MovieClip;\r\n static var mcD101 : flash.MovieClip;\r\n \/\/MovieClips (Buttons\/Other Elements)\r\n\r\n \/\/Text Fields\r\n static var tfText : flash.TextField;\r\n\r\n static var tfSpeedo : flash.TextField;\r\n static var tfAccelX : flash.TextField;\r\n static var tfAccelY : flash.TextField;\r\n static var tfAccelZ : flash.TextField; \r\n\r\n \/\/Text Format\/Styles\r\n static var ts = new flash.TextFormat();\r\n static var tsCenter = new flash.TextFormat();\r\n\r\n public function new(){\r\n \/\/Constructor - Most items are moved to main();\r\n fGestureStartX=0;\r\n fGestureStartY=0;\r\n }\r\n\r\n static function main(){\r\n \/\/Setup main MovieClip\r\n mcMain = flash.Lib.current;\r\n\r\n \/\/Set up some font styles\r\n ts.font = \"Arial\";\r\n ts.size = 24;\r\n ts.color = 0x00FFFF;\r\n\r\n tsCenter.font = \"Arial\";\r\n tsCenter.size = 24;\r\n tsCenter.color = 0xFF0000;\r\n tsCenter.align = 'center';\r\n\r\n \/\/Set up screens the new way\r\n \/\/var m100 = new M100(mcMain);\r\n \/\/var m101 = new M101(mcMain);\r\n\r\n \/\/Set up screens\r\n mcD100 = mcMain.createEmptyMovieClip(\"D100\", mcMain.getNextHighestDepth());\r\n mcD101 = mcMain.createEmptyMovieClip(\"D101\", mcMain.getNextHighestDepth());\r\n\r\n \/\/Set up text fields\r\n tfText = mcMain.createTextField(\"tfText\", mcMain.getNextHighestDepth(), 20, 20, 280, 100);\r\n tfText.setNewTextFormat(tsCenter);\r\n\r\n \/\/Set up text fields (D100)\r\n tfSpeedo = mcD100.createTextField(\"speedotext\", mcD100.getNextHighestDepth(), 20,50,280,100);\r\n tfSpeedo.setNewTextFormat(ts);\r\n tfAccelX = mcD100.createTextField(\"accelx\", mcD100.getNextHighestDepth(), 20,80,280,100);\r\n tfAccelX.setNewTextFormat(ts);\r\n tfAccelY = mcD100.createTextField(\"accely\", mcD100.getNextHighestDepth(), 20,110,280,100);\r\n tfAccelY.setNewTextFormat(ts);\r\n tfAccelZ = mcD100.createTextField(\"accelz\", mcD100.getNextHighestDepth(), 20,140,280,100);\r\n tfAccelZ.setNewTextFormat(ts);\r\n\r\n \/\/Set up text fields (D101)\r\n\r\n \/\/Initialise text\r\n tfText.text = 'Hello World!';\r\n\r\n tfSpeedo.text = 'Accelerometer Values...';\r\n\r\n \/\/Set up event handlers\r\n mcMain.onMouseDown = startGesture;\r\n mcMain.onMouseUp = endGesture;\r\n mcMain.onEnterFrame = update;\r\n }\r\n\r\n static function update(){\r\n tfAccelX.text = Std.string(ChumbyNative.getAccelerometer(5));\r\n tfAccelY.text = Std.string(ChumbyNative.getAccelerometer(6));\r\n tfAccelZ.text = Std.string(ChumbyNative.getAccelerometer(7));\r\n }\r\n static function startGesture () {\r\n fGestureStartX = flash.Lib.current._xmouse;\r\n fGestureStartY = flash.Lib.current._ymouse;\r\n }\r\n\r\n static function endGesture () {\r\n fGestureEndX = flash.Lib.current._xmouse;\r\n fGestureEndY = flash.Lib.current._ymouse;\r\n fGestureDeltaX = Math.round(fGestureEndX - fGestureStartX);\r\n fGestureDeltaY = Math.round(fGestureEndY - fGestureStartY);\r\n\r\n\t\t\/\/Rather than else-if, the following if's are deliberately done to allow compound gestures\r\n\t\t\/\/e.g. Up & Left, Down & Right etc.\r\n if (!Math.isNaN(fGestureDeltaY) && (fGestureDeltaY > 100)) {\r\n gestureDown();\r\n }\r\n\r\n if (!Math.isNaN(fGestureDeltaY) && (fGestureDeltaY < -100)) {\r\n gestureUp();\r\n } \r\n\r\n if (!Math.isNaN(fGestureDeltaX) && (fGestureDeltaX < -200)) {\r\n gestureLeft();\r\n }\r\n\r\n if (!Math.isNaN(fGestureDeltaX) && (fGestureDeltaX > 200)) {\r\n gestureRight();\r\n }\r\n }\r\n static function gestureRight () {\r\n tfText.text = \"To the right!\";\r\n mcD100._alpha = 0;\r\n \/\/tfText.setTextFormat(ts);\r\n }\r\n static function gestureLeft () {\r\n tfText.text = \"To the left!\";\r\n mcD100._alpha = 100;\r\n }\r\n static function gestureUp () {\r\n tfText.text = \"Bright!\";\r\n ChumbyNative.setLCDMute(0);\r\n }\r\n static function gestureDown () {\r\n tfText.text = \"Dim!\";\r\n ChumbyNative.setLCDMute(1);\r\n }\r\n}<\/pre>\n<\/blockquote>\nChumbyNative.hx<\/h3>\n
\n
class ChumbyNative{\r\n public static function getLCDMute():Int{\r\n return flash.Lib._global.ASnative(5,19);\r\n }\r\n public static function setLCDMute(x:Int):Void{\r\n flash.Lib._global.ASnative(5,20)(x);\r\n }\r\n public static function getAccelerometer(x:Int):Float{\r\n return flash.Lib._global.ASnative(5,60)(x);\r\n }\r\n}<\/pre>\n<\/blockquote>\nMchumby.hxml<\/h3>\n
\n-main Mchumby
\n-swf-header 320:240:12:000033
\n-swf-version 8<\/p><\/blockquote>\n","protected":false},"excerpt":{"rendered":"