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Hi, yesterday I'm trying the electronics. All work successful. All axis work fine. But today not. If I start the computer the let witch indicate the power on is turn on. That's mean the board drain power from lpt and not from external power supply 5volts witch is still off. The led is light little bit lower as with the eternal power on. And the big problem is that, the motors don't move.. I don't know where is the problem.. Broken lpt port, or breakout board.. Please help. Brandon
Hi Brandon
do you have a link to the manual for the 1205 BOB ?
do you have a multi meter ?
I only found a photo of the BOB
Attachment 301960
I assuming the two 16 pin IC's will be 74HC14 inverters
with no power to the board and a logic 1 (+5V) on any of the printer port outputs
the BOB will work to some degree
current will flow via the IC's input protection diodes to the positive supply pin 16
and power the other IC and the LED indicator at a reduced voltage
note - if all printer port pins are at a logic 0 (0V) the board will stop working
Attachment 301966
check you have power to both power supply inputs for the pc interface and output side of the BOB
a photo or diagram showing how you have connected the board will help
John
PS
high resolution photos of both sides of the breakout board will make it possible to trace the circuit
and then work out how to test it` in more detail
Hi
I have a problem where I do not see any pulses coming through on pin2, which is my step pulse, but I do see the direction pulse changing. If I check the parallel port of the computer I do get the correct signals. Please advise.
since my reply in post 2
I have traced this circuit for the BOB
Attachment 401404
with the PDF data for the 74HC14 IC
Attachment 401406
you should be able to follow the step signal from the printerport pin
to the input pin of one of the 74HC14 IC pins
and then from the corresponding output pin to the opto isolator
John
Hi John
I have downloaded port monitor app and can control the pins through that. If I switch pins on and off, I do get that coming through. It is only when I run mach3 that I do not get my step pulse. I do get my direction pulse. Any advise on that.
Its possible your step pulses are too short to be passed through the very slow OPTO couplers on the board.Quote:
Originally Posted by Johan1007
you could try doubling your step time until it works to get an idea of how slow...
On further investigation, we found that the opto couplers is switching to slow, the data sheet specifying a rising time of 18µsec. The max we could managed to set it in Mach3 is 15µsec. At the end of the day it is just a bad quality board.Quote:
Originally Posted by PCW_MESA
Have decided to go for something better.