[radicooldude]

I have two HP HEDS 1600ppr encoders, and I built the circuit posted at
http://www.lindsayengraving.com/othe...rests/dro.html
I then used their FREE dro software, and I finally got it to work. THe problem is that the software reports that there are a lot of encoder read errors (it estimates if it thinks it sees one).

Has anyone gotten an encoder to work with this software? Please post your setup and how you got it to work. Thanks, Zachery

[Bubba]

Zachery,
Yes, I got it to work very well! I also had that problem early on and some of the people that built it also had the problem. But for the life of me, right now I cannot remember the reason
All I can remember is playing with it until all of a sudden, it locked in and ran smoothly. Seems as though it was a setting in the configuration file, but don't remember which one.

Are you running in the polling mode or interrupt mode?

Bubba


PS: Your are running this in PURE DOS, NOT a dos box in windows aren't you?? If your running in a dos box under windows, the timing will be all messed up!

[radicooldude]

Hey, I do not understand what you mean by the polling and interrupt mode. Can you elaborate? The only software versions that work right now with my pc is DRO 4x, NOT the 5x versions. What encoders are you using, and how did you interface them with the computer?

[Bubba]

The interrupt mode (IRQ) or polling depends on the interface.
Basically, the polling mode is nothing more than a buffer with pullup resistors and fed into the parallel port. All timing is handled by the computer based on a continious poll of the port.
In the IRQ mode, there is slightly more hardware on the interface card and it will generate interrupts and tell the computer when to read the port.

Both interfaces are on my web site and IFIRC, the v5.x requires this interface. It has been a long time since I have played with the program as all my stuff is now cnc'd:})

Did you use the transistor or IC approach to the interface???

[radicooldude]

I used two PNPs per encoder, and followed the sketch on your site.
All that there is to the interface is the encoders connected to the PNPs then to the parralell port. The +5v and ground connect to the encoders, the 5v to the PNPs, and the ground to pin22 on the parrallel port according to your sketch.

[Bubba]

OK, you are using the "polling" method! I was never able to get that one to work and that is why I came up with the original IC method. But by adding a couple more IC's for the IRQ method, it worked much better and IIRC, this method must be used by V5.x (not my build)

Bubba'