Finished my CNC router I'm quite happy with it, this awesome feeling when you see it finally moving ^^.
Some pics
As you can see circular interpolation as well as linear interpolation work well.
I've used the G-code interpreter posted by aventgps(is or was also member here) apparently it's reprap firmware, however the newer versions don't look alike.
Bit more info
Steppers do 48 steps per revolution
Were initially unipolar but I cut the center wire so they act as bipolar now.
The one for the X axis is a pm55l048
I do suggest stronger steppers these probably won't be moving a mill even if it's through balsa.
If anyone can suggest some good ones would be appreciated.
I used two l239d quadruple H-bridges to drive the steppers. The circuit can be found on the main site.
I hope to gain some more experience with it before I move to a bigger model
Probably will spend the hollidays writing a spoonfeeder and some programs which output G-code.
When I see it moving it remembers me of that one song "She's incredible math. Just incredible math" ^^
Special thanks to johnwasser and PeterH for the quick response while troubleshooting.
I don't see how it might be causing your symptom but the search_string() function doesn't put a terminator on 'temp' before calling strtod(temp, NULL).
If X and Y only go in one direction, how did you draw the square?
The limiting switches. Even though there aren't any connected.
I've noticed some particles file-dust under the arduino perhaps it allowed some current to pass or the arduino might be having some trouble.
May check it tomorrow.
Anyways I've changed the min and max pin numbers
Everything works fine now.
Tentationem:
The limiting switches. Even though there aren't any connected.
If the switch inputs are floating, they'll return arbitrary values and could be affected by the tiniest things. If they aren't connected, make sure your sketch doesn't read them or else pull the inputs to the normal position.