I have an older Linuxcnc installation that uses a parallel port. It has 4 TCRT5000 optical sensors, that I was powering the IR LED with an output from the parallel port (and reading the IR sensor with an input.) It had been working fine for some time, but I only use this equipment once a year. This year when I drug it out of storage I could not get one of the sensors to work. After several hours of checking and rechecking every connection and trying multiple sensors, I figured out that the LED on the sensor that wasn't working simply could not draw enough current from the parallel port output to light bright enough, even though it had been working in the past. I switched it from pin14 to pin7 and full functionality was restored. Does this sound like I've partially ruined pin14 on the parallel port? (It still turns on and off.) Do different parallel port output pins have different current sourcing capabilities?
I'm a little surprised that this happed to this sensor rather than the other 3, because it is fed through about 30 more feet of wire than the other 3 that are still working happily (fed by output pins 2-4.) I guess I should probably set up an alternate power source for the LEDs on the sensors, but they had been working fine before and I didn't feel like doing the additional wiring. Todd Zuercher P. Graham Dunn Inc.<http://www.pgrahamdunn.com/index.php> 630 Henry Street Dalton, Ohio 44618 Phone: (330)828-2105ext. 2031 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
