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Author Topic: CNC4PC breakout board led operation??  (Read 4123 times)

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CNC4PC breakout board led operation??
« on: January 22, 2008, 02:55:20 PM »
Ok, just checking here...

I just installed my new C1G card from CNC4PC, the leds are acting oddly. some are dimly lit, others turn on and off if I touch the board. I have nothing wired to the board other than 5V external power and my pc.

Can someone confirm the correct led behavior? As I recall on my last machine, the step led should be lit when the axis is moving, while the dir led latches between on and off based on the direction....is this correct?

I'm thinking my breakout board is bad.

Chuck



Re: CNC4PC breakout board led operation??
« Reply #1 on: January 22, 2008, 05:47:50 PM »
the cnc4pc board needs both an external 5v power source and 5v from the usb port , if just one of the 5v inputs is powered it will cause the leds to dimly light.
Re: CNC4PC breakout board led operation??
« Reply #2 on: January 22, 2008, 09:05:38 PM »
Well, I did some pin by pin testing this afternoon...setting each of the output pins as a direction output, i can freely turn on and off all the leds except for pins 1,2,3,4. I then hooked the board to my LPT2 port and it had the same behavior. I then did the same test but instead of watching the LEDs I just measuured the voltage at the parallel cable. I was able to manipulate all the output pins (1-4 included)....everything is pointing to a bad CNC4PC C1G board....frustrating!!

Offline Chaoticone

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Re: CNC4PC breakout board led operation??
« Reply #3 on: January 24, 2008, 08:27:22 AM »
If you are replacing an older cnc4pc board with a new, you may want to check the logic. It has been reversed on some of them. I'm not sure if yours is.

Brett
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Re: CNC4PC breakout board led operation??
« Reply #4 on: January 25, 2008, 09:49:14 PM »
I have a couple of c11 cnc4pc boards and it requires two seperate 5v power supplies and both have to be hooked up for it to work. one can pull 5v from the USB port and is a simple 2 terminal screw strip and the other needs a seperate 5 power and is a longer connector on the other end of the board, They both have to be hooked up for the board to work, and they have to hooked to two seperate power sources  to maintain opto-isolation . The condition you describe will occur if only the long one is hooked up