Hello Guest it is November 29, 2020, 02:09:09 AM

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.

Topics - ClaudioArrau

Pages: 1
General Mach Discussion / 3.3 volts of parallel port
« on: December 24, 2009, 10:15:30 PM »
Hello everyone, Merry Xmas to all
This is my first time that i buy a cnc system. Got it in parts (from many countries) and now i am trying to make it work.
I am using a laptop. Unfortunately the breakout board hasnt arrived yet
First things first. The driver is the Q2HB88M
It is optocoupled, and as "interface" i use a unl2803. It has 2.7K input resistance and it is mainly for TTL signal. I use +5 volts from a USB. No resistors/transistors etc, just the ic itself with a 10uF capacitor across the power lines.

Problem: I hooked a stepper to the driver. From mach3 mill i can turn the stepper using up and down keys, but whatever i press, it turns in one direction only.
It simply rejects the DiRection signal. Note that when i press UP it moves. When i press DOWN, the state of DR changes.... but the motor moves like previously.
The low value is 0.8 volts and the high is 4.something. I will post the exact values tomorrow !

Any ideas ? Tommorow i'll hook a PCI cart to a PC and see if that parallel port works

Thanks for any advice.

Pages: 1