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Diffstat (limited to 'README.md')
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@@ -26,6 +26,52 @@ The expected format of an event message is: This format is good for something like a button event, where there are two discrete pieces of information in the measurement. +## Raw CAN Message format + +An OpenXC vehicle interface may also output raw CAN messages. Each CAN message +is sent as a JSON object, separated by newlines. The format of each object is: + + {"bus": 1, "id": 1234, "value": "0x12345678"} + +**bus** - the numerical identifier of the CAN bus where this message originated, + most likely 1 or 2 (for a vehicle interface with 2 CAN controllers). + +**id** - the CAN message ID + +**data** - up to 8 bytes of data from the CAN message's payload, represented as + a hexidecimal number in a string. Many JSON parser cannot handle 64-bit + integers, which is why we are not using a numerical data type. + +## Trace File Format + +An OpenXC vehicle trace file is a plaintext file that contains JSON objects, +separated by newlines. + +The first line may be a metadata object, although this is optional: + +``` +{"metadata": { + "version": "v3.0", + "vehicle_interface_id": "7ABF", + "vehicle": { + "make": "Ford", + "model": "Mustang", + "trim": "V6 Premium", + "year": 2013 + }, + "description": "highway drive to work", + "driver_name": "TJ Giuli", + "vehicle_id": "17N1039247929" +} +``` + +The following lines are OpenXC messages with a `timestamp` field added, e.g.: + + {"timestamp": 1385133351.285525, "name": "steering_wheel_angle", "value": 45} + +The timestamp is in [UNIX time](http://en.wikipedia.org/wiki/Unix_time) +(i.e. seconds since the UNIX epoch, 00:00:00 UTC, 1/1/1970). + ## Official Signals These signal names are a part of the OpenXC specification, although some @@ -96,22 +142,6 @@ manufacturers may support custom message names. * numerical, -179.0 to 179.0 degrees with standard GPS accuracy * 1Hz -## Raw CAN Message format - -An OpenXC vehicle interface may also output raw CAN messages. Each CAN message -is sent as a JSON object, separated by newlines. The format of each object is: - - {"bus": 1, "id": 1234, "value": "0x12345678"} - -**bus** - the numerical identifier of the CAN bus where this message originated, - most likely 1 or 2 (for a vehicle interface with 2 CAN controllers). - -**id** - the CAN message ID - -**data** - up to 8 bytes of data from the CAN message's payload, represented as - a hexidecimal number in a string. Many JSON parser cannot handle 64-bit - integers, which is why we are not using a numerical data type. - License ======= |