Add header guard to lin.h file.

[ChrisPHL]

The code in lin.h file should be surrounded by header guard like this:

#ifndef LIN_H_
#define LIN_H_

// Code goes here.

#endif // LIN_H_

This way it can be included from several files at the same time without having problems of "redeclarations".

Have a nice day! :-)

Chris

[gandrewstone]

I've lost my LIN test setup. Can you make a PR with this and your prior report and if it works for you, I'll merge it. I hesitate to make any changes at all without at least a basic test, although this one ought to be completely innocuous....

[ChrisPHL]

I'll do! :-)
This one works for me perfectly of course.
I did test the diagnostic checksum utilizing a Saleae clone logic analyzer. It works for me perfectly, too.

[ChrisPHL]

Btw: The Merge request is waiting... ;-)