Jason Gaunt / GMLAN

Libraries to support working with GMLAN - General Motors CAN BUS network in most of their vehicles between 2007-present day. Please note this is a work in progress and not guaranteed to be correct, use at your own risk! Read commit logs / subscribe to see what has been added, it's a work in progress after all ;)

GMLAN.cpp@2:1a2cb289f24d, 2013-02-19 (annotated)

Committer:
foxdie
Date:
Tue Feb 19 22:28:25 2013 +0000
Revision:
2:1a2cb289f24d
Parent:
0:9266fbfbef88
Child:
3:09fdfec053cd
Added initial list of known Arbitration IDs from the GMLAN Bible located at http://is.gd/gmlanbible - a project I am a curator of. Credit also due to TMK for his hard work too and the other developers who work tirelessly.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
foxdie 0:9266fbfbef88 1 /*
foxdie 0:9266fbfbef88 2 GMLAN.cpp - Source file for GMLAN Library
foxdie 0:9266fbfbef88 3
foxdie 0:9266fbfbef88 4 GMLAN is a Controller Area Network Bus used in General Motors vehicles from
foxdie 0:9266fbfbef88 5 roughly 2007-onwards. Its purpose is to allow various Electronic Control Units
foxdie 0:9266fbfbef88 6 (aka ECUs) within a modern vehicle to share information and enact procedures.
foxdie 0:9266fbfbef88 7
foxdie 0:9266fbfbef88 8 An example of this would be communication between the HU (Head unit) and the
foxdie 0:9266fbfbef88 9 DIC (Dashboard Information Cluster), when you adjust the volume up / down, this
foxdie 0:9266fbfbef88 10 is reported to the cluster to be displayed.
foxdie 0:9266fbfbef88 11
foxdie 0:9266fbfbef88 12 It is the function of this library to "crack open" this world to allow anyone
foxdie 0:9266fbfbef88 13 with only as little as a few hours of C++ programming under their belt to get
foxdie 0:9266fbfbef88 14 started in what can sometimes seem a daunting world.
foxdie 0:9266fbfbef88 15
foxdie 0:9266fbfbef88 16 Jason Gaunt, 18th Feb 2013
foxdie 0:9266fbfbef88 17 */
foxdie 0:9266fbfbef88 18
foxdie 0:9266fbfbef88 19 #include "GMLAN.h"
foxdie 0:9266fbfbef88 20
foxdie 0:9266fbfbef88 21 void CANHeader::decode(int _header) {
foxdie 0:9266fbfbef88 22 priorityID = (_header >> 26) & 0x7;
foxdie 0:9266fbfbef88 23 arbitrationID = (_header >> 13) & 0x1FFF;
foxdie 0:9266fbfbef88 24 senderID = (_header >> 0) & 0x1FFF;
foxdie 0:9266fbfbef88 25 }
foxdie 0:9266fbfbef88 26 int CANHeader::encode(void) {
foxdie 0:9266fbfbef88 27 long int buffer = 0;
foxdie 0:9266fbfbef88 28 buffer = (buffer << 3) | 0x0; // 3 bit padding
foxdie 0:9266fbfbef88 29 buffer = (buffer << 3) | priorityID;
foxdie 0:9266fbfbef88 30 buffer = (buffer << 13) | arbitrationID;
foxdie 0:9266fbfbef88 31 buffer = (buffer << 13) | senderID;
foxdie 0:9266fbfbef88 32 return buffer;
foxdie 0:9266fbfbef88 33 }