pwm schematic help required please?

[Doddy]

Just do this:-
Connect the BOB output pin P1 to ribbon Pin 3. Connect the Ground used for the BOB to ribbon Pin 4. There is no need for any of the resistors.


To answer your question:-
Google Mach3 Spindle Settings to find out how to setup. What I meant by "calibrate" was perhaps misleading, my fault.

My intent, when you issue lets say a speed of S1000, that the actual speed would be a ratio of the commanded speed vs the maximum spindle speed - so if the max spindle speed was set within Mach to 2000rpm, then a S1000 command would set the PWM output at 50% Mark/Space. If the max spindle speed was set within Mach at 4000rpm, then the same S1000 command would set the PWM output at 25% Mark/Space ratio. My comment was to ensure that the commands that you issue to test the speed control would respond with a sensible response from the PC/machine.