Making some extremely cheap stepper motor drivers

So we are planning to use a3982 or a3983 stepper motor drivers for the final Hydra-MMM design, however, both these chips have one major limitation: they are SOIC and TSSOP packages. Neither of these packages play well with the tools that most hobbyists have available such as breadboards or general purpose PCBs (the plates with hundreds of little holes drilled in them). For this reason, I have been working over the past week to get an extremely cheap, through hole packaged, 4-motor stepper driver board up and running. The board uses PIC microcontrollers to handle the stepping functions and external MOSFETs for the high current switching. The part count for a single stepper motor driver is extremely low and also very cheap! The required parts are shown below

The only required parts are 4 MOSFETs, 1 14-pin IC, and a 100uF decoupling cap. The LEDs, resistors, female headers, and IC socket are just to make the whole thing a little easier to debug and wire up. With the MOSFETs costing about a buck a piece and the IC being $5, the total is very close to $10! Now, while I am using a stepgenie IC for this design (http://www.stepgenie.com/), I have also built the exact same thing using a generic 14 pin microcontroller with my own firmware. Both methods work, however, I already had several stepgenie IC's so I might as well use those and save the other microcontrollers for other projects.

After making the schematic and testing the whole thing on a breadboard I went ahead and made a single-sided eagle pcb that would allow this driver to be made extremely easily on any cartesian machine that has milling capabilities (later versions of mendel??). PCB milling and drilling isn't too hard as long as your machine has the accuracy and rigidity required, but making only a single-sided board simplifies things greatly. The eagle files can be downloaded here: https://sourceforge.net/projects/hydra-mmm/files/Electronics/StepGenie-Stepper-Motor-Driver-PCB/

Another big advantage to designing single-sided boards is that they can easily be prototyped on general purpose pcb boards, which can be purchased at any radio shack or electronics supply store. I heated up my trusty Weller soldering iron and made 4 of the stepper motor drivers. I also added a 5V regulator with a 4-pin Molex input and a mode selector switch for choosing between wave drive, half step, or full torque modes on each driver. Some pictures of my hard work are below

I tested the whole thing with a couple motors and my spare Arduino and it worked wonderfully! The half stepping mode is relatively smooth, especially when running them at a high stepping frequency (~1kHz) which is what we will be using most of the time for the leadscrews used on Hydra.

While the full-blown Allegro based stepper motor drivers that Reprap and Makerbot currently use are surely superior, this design is one that is less expensive and easier to make with everyday tools, which may make it a winner for other hobbyists working on a budget. Let me know what you think in the comments!