Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: Zero Cool on April 20, 2011, 10:26:07 PM

Title: PWM VS Pins 2-9
Post by: Zero Cool on April 20, 2011, 10:26:07 PM

Why is it that i can only get Mach to output a PWM signal on pins 2 through 9???

Pins 1, 14,16 &17 are output pins as well but no matter what i do i cannot get a PWM signal on these pins. but pins 2-9 work just fine???

 I see that Mach has a setting to use port2 pins 2-9 as inputs instead of outputs. I was hoping to use that functionality but i can if i cant get a PWM signal to work on pins 1, 14,16 or 17

Title: Re: PWM VS Pins 2-9
Post by: ger21 on April 20, 2011, 10:36:58 PM

I use PWM to control a Super PID speed control and use either pin 14 or 16, but don't know which right now.

What are you trying to do?

Title: Re: PWM VS Pins 2-9
Post by: Zero Cool on April 20, 2011, 10:41:25 PM

I need to output the pwm signal to my custom built motor controller.

I looked at the SuperPID units and the units i saw are not PWM....Pulse Width Modulated. they are a traic based controller. how are you interfacing the PWM signal to the SuperPID??

Title: Re: PWM VS Pins 2-9
Post by: ger21 on April 20, 2011, 10:49:51 PM

I built a simple circuit to convert the PWM to 0-5V. It's on page 22 of the manual, and only cost a few $.
http://www.vhipe.com/product-private/SuperPID-v1_Instructions.pdf

Title: Re: PWM VS Pins 2-9
Post by: Zero Cool on April 20, 2011, 10:54:40 PM

I built a custom motor controller that takes the PWM signal, opto isolates it and feeds it to a IC Mosfet driver and then to a power Mosfet to control the spindle motor directly. works great! But i want to use Pins 1, 14,16 or 17 to output the PWM signal.

 I have a dual Parallel port card in my PC. and i tried both ports and same deal.

Title: Re: PWM VS Pins 2-9
Post by: Zero Cool on April 27, 2011, 06:54:09 AM

I am having other problems now. I moved things around to get a PWM output from pin 6 and its not working. I have figured out that if i press the rest button the PWM will start. but only at the minimum speed. If i press the speed up/down buttons it just shuts off.

 I want to use 400hz as my PWM base frequency. I have a direct drive spindle. I have the pulley ratio set for 5000min and 30000max with a ratio of 1