# Thread: STK672-110 diagram help, mosfet questions and more!

1. ## STK672-110 diagram help, mosfet questions and more!

I've been searching the net for a couple days now, to see if anyone else has build a driver board with this particular IC. I have come up with a few similar, but all in languages I am not fluent in. And on top of them being in other languages, they also use different chips.

Based on the Datasheet, I can guess that

Pin 1 = Gnd
Pin 2 = BB (Stepper Motor)
Pin 3 = B (Stepper Motor)
Pin 4 = AB (Stepper Motor)
Pin 5 = A (Stepper Motor)
Pin 6 = ResetB (whats this do? Like a stop?)
Pin 7 = CWB/Direction
Pin 8 = Mode (Huh? Nevermind how to select what mode, im lost)
Pin 9 = Clock/Speed
Pin 10= Vdd (What is this?)
Pin 11= SP (Power input?)
Pin 12= Ref (What is this?)

So... I tried to come up with a diagram of how i'd make a circuit based on the datasheet.
This is the first one i came up with, but i noticed i missed a capacitor.
So this is what i came up with next. Im sure it can be cleaned up but I tried as hard to follow the example diagram on the datasheet as possible.

http://i441.photobucket.com/albums/q...ecircuit-1.jpg

If Mode was connected to ground, what stepping would it be? Full? Half? 1/8th? 1/4?

If you can offer any feedback I'd appreciate it. I know nothing about electronics, but im googling everything I can, trying to learn as I go. If you understand this, and can explain why something does what it does i'd be grateful.

If I wanted to run my motors at 5v, Do i need to calculate R01 and R02? Im still lost on that one. Vref controls the current output on a/ab/b/bb, say I want to run 1.8a on each output, what resistors would i need? Also, do I need diodes on each of the outputs to prevent power flow back into the chip? Forgive a noob for all the questions, but this is how i learn.

2. I posted this on another forum so thats why its worded the way it is. If i cant figure out how to get my stk672 to work, i'll try this way!
So i've decided that my STK672-110 are WAY over my head. There is no easy to read instructions on how to interface them to the computer, and i'd rather go with something that wont limit me down the road. (1.8a wouldnt do squat on a larger cnc stepper)

So... Here is my plan. I want to build a small CNC machine to learn with. Maybe 8X8X3 Travel.

C-10 Breakout Board It has nice features, and makes for easy wiring.

Step Genie IC's FrankG uses Allegro 5804B's, and these are the more "modern" version of these.

For motors, im going to start small, because i allready have 3 identical motors, and have identified the wiring. They are 6.7v 1.2A 1.8 Deg/Step.

The only question i have so far is the Step Genie's require the use of HeXFet's. (N-Channel MosFet) How do i figure out which one I'd need to power my motors? The Step Genie only outputs 25ma (at 5v im assuming, since thats what powers the IC) I've emailed Step-Genie to see what they have to say, but it never hurts to ask right?