View Full Version : 595 Big trouble **All fixed**

11-08-2007, 06:07 AM
Hey all....

Someone told me to post here for help.....

I'm going mad!!!!!

I have made a 48 ch 595 on strip board. Checked the soldering 10 times. Connected the computer.....NO JOY.

All earths from the port are grounded.

Power supply to 595 of 5.2 or 4 volts does not make it work.

I have an oscilloscope and can't read any data from pins 1,2 or 14.

I have selected EPP in bios.

I have tried the simple and the olsen 595 plugin.

Any help appreciated......


LG in Australia

It is important to have the port plug wired at the correct end :) :) :)

11-08-2007, 08:37 AM
Since you have an oscilloscope this should be easy to find.

Use the Olsen 595 plug-in, make sure you assign all 48 channels to port 1.

Create a sequence for 48 channels and have something changing in every event interval. Data is only sent when data changes.

To make sure that its not your computer, check the pins on the parallel port without being hooked up to your Olsen. Vixen doesn't need to have a board hooked up to send the data to the parallel port.

Pin 1 - Clock signal, should see 48 pulses for each event. Each pulse has a pulse width of approx 10-20 usec.
Pin 2 - Data signal, should see pulses for each ON event (ON events next to each other appear as one large pulse)
Pin 14 - Strobe signal, should see 1 pulse at your event interval rate

If you don't see these signals at your parallel port then you might have a dead port or something in your BIOS settings are wrong.

If you do have the signals at the port, consider the quality of the signal. What is the maximum voltage of a HIGH signal? Will it be enough to trigger the 595 chips?

Then plug in your board and check at the first 595 chip. Compare the quality of the signal compared to directly at the port. Are you losing signal in the cable between the computer and 595?

At the chip:
Pin 11 - Clock signal
Pin 14 - Data signal
Pin 12 - Strobe signal

That should get you some answers and hopefully point you in the right direction. Check back with what you find and we can go deeper in need be.

11-08-2007, 10:01 AM
It is important to have the port plug wired at the correct end :) :) :)

I can't count the number of times that I've used advanced diagnostics to determine that things work better when they're plugged in.

Glad you got it fixed!