Lets take an sequential approach for the troubleshooting.
-First we need to make sure the input signals are being received (with proper TTL levels) from the PC interface.
In order to do the following tests we need to have a common schematics to refer to, the one I am using now is:
http://www.fromorbit.com/projects/pi...4_0_schema.pdf
The test circuits on your links could make you reach the wrong conclusions because there is no debouncing on the switches and only one action on the step switch could produce several successive steps at the output or movement in sudden bursts, what makes difficult to see if the PIC is providing the expected outputs. It is better and easier to use Mach3 to produce the pulses, but we don't know yet if the problem is coming from the Mach3 step/direction pins configuration.
Your Mach3 configuration should reflect Step "Active Low" and Direction "Active Low" on the proper pins.
-Disconnect the motors from the power chips. Disconnect VCC cables from CONN2 (A1out, A2out, B1out, B2out)
-Program J1 jumpers for "Full STEP" mode.
-Connect the 5 volts and Ground to the input connector CONN1, as well as the PC Lpt interface cables, and pins 18 to 25 of the LPt port to GND.
You can use your multimeter to test at pin 6 and Pin 7 of the PIC for logic level changes (the other test lead should be connected to pin 6,7,8 of CONN1).
While jogging with Mach3, Measure the voltage at pin 7 of the PIC, less than 0.8 volts is a logic Low, higher than 2.4 volts is a logic High.
Voltages in between indicate a problem in the Lpt port.
1-Take a note of the voltage while jogging Forward.
2-Take a note of the voltage while jogging Reverse.
You should have seen a reversal of the logic voltage during the second step.
If everything went OK, reverse the pins on Mach3 configuration (step where direction was and vice-versa), this will make the step pin receive the direction signal while the direction pin receives the step signal. The purpose of this step is to have a controlled logic level at the input that does not change with time, and thus can be accurately measured with the voltmeter, while being able to provide a logic status change by using the forward and reverse keys for the chosen axis, instead of a pulse sequence (step Signal).
-Put your voltmeter probe at pin 6 and repeat steps 1 and 2
You should get two different logic levels like in the prior test. Stop and let me know the results.
For the next set of tests I need you to build the logic probe on Pminmo's troubleshooting guide. Let me know when you are ready.
Regards,
Kreutz.