Proto 3977 COntroller

[pminmo]

Just thought I would share some of mine and a buddies electronics were working on: First board is based on a Allegro 3977 chip. http://webpages.charter.net/pminmo/proto3977.jpg
Has input signal conditioning, can run full step or micro step of the 3977, it's designed to cable to the second board of my buddies:http://webpages.charter.net/pminmo/protoset.jpg

The second board is setup to run 3 of the 3977 boards, takes the parallel port in, properly signal conditions those signals. Also takes 3 axis of limit switch logic for enabling and diabling the drivers.

Phil

[radio-op]

Nice work Phil! Are you planning to sell the boards and/or kits? What are the specs on that drive chip, amps per phase?
Bill

[pminmo]

Probably not, may put the design in the FTP section. I might be willing to order boards for people, but I don't want to get in the manufacturing business. The chip does up to 2.5A at 35VDC, bipolar steppers. Steps in full, half, quarter, or eighth. Inputs are Dir, Enable, Step, Reset. The Enable, Dir and Step inputs are cmos compatable with schmitt trigger inputs for noise rejection. A person needs to be able to do very fine soldering as the 3977 is a surface mount part.

[radio-op]

I hear that about manufacturing, can turn into a time sink real easy. Offering boards would be hard too, the flat pack chip would be a stumbling block for alot of people. I've seen project boards where the surface mount part is pre mounted, but that can kill you if you don't have a reflow oven or rework station. What cad program are you using, Eagle?
Bill

[pminmo]

Yes, Eagle. It's a really good tool. I would have to buy the real copy if I were to try to profit from the design, another reason I'm not really interested in selling built boards. If somebody wanted some bad enough I might consider trading for some CNC stuff.

[radio-op]

I use Ivex Winboard, started with the demo and added pins, so now I have about a 400 pin limit. Its not the most cost effective way, but there's no limit on the size of the board just the pin count. I just upgraded a little at a time, whenever I ran into the limit.
Heard good things about Eagle, but already 'invested' in WinBoard. The Eagle demo is just limited to board size, 3.5" x 3.5"?
Bill

[pminmo]

4 x 3.2" and just two layers. Autorouter and library is pretty extensive. Fairly easy to use, but the more and more you use it, the more you find out how powerfull it is.