Hi, I'm trying to work on a project where I'm building my own little logger with display screen and part of that is reading the odometer values using a OBDII cable and then displaying them on a screen and logging them.

I can get the value using forscan no problem, but it doesn't detail how it converts what looks to be hex from OBD to a decimal value I can understand. For example this is the value I get:

62DD0102FD37 and it's approximately 194,000 km

I've had a bit of play with the numbers converting them but I'm not able to get to the right value, any ideas anyone? I know it's a pretty niche question

I don't think that is hex...

Excel has the two functions, hex to dec, and dec to hex

194000 is 

2F5D0

What do you think it could be? It’s a weird one, FORScan clearly knows how to convert it! But it’s not obvious how they do it

Drive for a bit, say a nice round 10km, then see how the 'hex' value looks then. It might give some clues as to how the figure is represented. I expect it is indeed hex, and of course the symbols seen so far fit with this.

Also, please do quote the decimal figures exactly otherwise any budding codebreakers out there won't be able to play around with the figures to work it out.

There might be some checksum digits included in the string which will make reverse engineering all the more difficult.

14 hours ago, AshleyC said:

62DD0102FD37 and it's approximately 194,000 km

62DD0102FD37 =  195,895 kM

As per the suggestion above from @MJNewton you need to drive about and get some more values to compare. There's a good chance that at least part of that hexadecimal number will be a checksum.