Marlin/ramps 1.4 homing in the wrong direction?

I've got an issue with all the axes on my machine where they will home fine, stepping in and out of the optos and registering x0,y0,z0 when m114 is sent in pronterface but once they are homed I can't moved the motors away from home.
they can be sent further towards home.
For example if I tell it to home X and then +1mm X , m114 will give x1, y0, z0 when *physically* the machine is at x-1, y0 ,z0
When I changed #define INVERT_X_DIR form true to false, it homed relentlessly into the side of the machine, ignoring the endstop triggering.
I also tried altering #define X_HOME_DIR -1, which gave the same result.
In pins.h I just switched the values of the min pin and max pin, not sure if that was the right thing to do?
Any thoughts? : S

Edited 1 time(s). Last edit at 12/07/2013 11:32AM by blabberjack.

Ah I got it, installed repetier and encountered the same issue, after a bit of fiddling about I discovered that the logic of my endstops needed inverting!
I haven't tested it with marlin as I think I will just stick with repetier now I have it working, but I assume it's the same issue- hope that helps someone!

Hi Blabberjack
I used to have a similar issue and I've find out that is not a firmware or configuration issue but hardware in my case

Try to check the confiuration for your endstops and how they are connected to the ramps (or any board you're using). Use a multimeter to determine which pin on the endstop is open and which one is closed by default. And in the firmware check if you are using open or close states for these.

Sometimes when an endstop is always pressed the firmware behaves as you mentioned before. It took me almost a day to realize that

Try to check your endstops and let me know how it worked.
Upload some pics of your printer to see if there is a connection problem

Regards