TUM/2015/ppc

GPS on CAN

In this task you will need to receive Can-frames on the can-bus that contain the GPS location of the vehicle. The raw data has to be converted to arc-milliseconds

1°2'5" == (1*3600+ 2*60 + 5)*1000

Beware that the system you are running your code on will not support floating point operations. Use only unsigned and signed integers! Still the precision of your calculations has to be +-100 milli-arc-seconds

Conversion to Arc-Degree

inDegree hex = 180/(2^31-1) * (hex) [°]

GPS Datalayout in CAN Message

	Byte7 ST_LAT_NAVI
	Byte6 ST_LAT_NAVI
	Byte5 ST_LAT_NAVI
	Byte4 ST_LAT_NAVI
	Byte3 ST_LONG_NAVI
	Byte2 ST_LONG_NAVI
	Byte1 ST_LONG_NAVI
	Byte0 ST_LONG_NAVI

Byteorder

Little Endian (Least Significant Byte is at lowest address)

Status Longitude Navigation

	ST_LONG_NAVI

Possible Values

	-180° ...  +180°

signal type

32 Bit Signed Integer (Byte 0 ... Byte 3)

Invalid Data

Invalid-Value: 80 00 00 00h Signal not available value: 7F FF FF FF

Status Latitude Navigation

	ST_LAT_NAVI

Possible Values

	-180° ...  +180°

signal type

32 Bit Signed Integer (Byte 4 ... Byte 7)

Invalid Data

Invalid-Value: 80 00 00 00h Signal not available value: 7F FF FF FF

Running the tests

you will need a working ruby installation to execute the tests

Install the bake tool

see https://esrlabs.com/gems/doc/bake-toolkit/

run the tests

execute rake run from this directory