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

Dynamic allocation is not supported on the system.

You will have to complete the GpsConverter.cpp (and .h).

Conversion to Arc-Degree

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

HINT 1

Try to use constants as much as possible, isntead of computing stuff on the go.

HINT 2

In order to aviod losing decimals first multiply with a large factor and then divide to get the result in ms.

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 00

Signal not available value: 7F FF FF FF and FF FF FF FF

Do not forget to check for these values

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 00

Signal not available value: 7F FF FF FF and FF FF FF FF

Send the data over to the AC

Use the IGpsACPusher.

Running the tests

you will need a working ruby installation to execute the tests

run the tests

execute rake run from this directory

Install the bake tool

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