The stuff in the open source area is disappointing to say the least, the concept of incomplete schematic drawings or the collection of partial drawings forcing you to connect the dots is a poor platform to work from.

I'm looking for a schematic for a bipolar (4 wire) stepper motor.

Yes, you will say use google but over the years this has been filled with so much crap that it seems impossible to find anything useful so please don't suggest searching for anything, I've already tried this and after several weeks could not find anything beneficial.

Requirements are simple, step, dir, home, limit and estop.

Selectable microstepping down to 1/8th would be nice.

Current limiting/control would also be nice since it offers some protection.

The use of AVR components is not out of the question but requires further discussion related to the benefits and features of such designs.

If you have something please provide a JPG or PDF so we can discuss the circuit without having to resort to all kinds of software just to view the schematic.

NOTE: the reason to use mosfets is a simple one, it allows scalability regarding current capability and also simplifies assembly however the use of SMT is not out of the question regarding other components.