Mesa 7i96 options for PWM output?

More
04 Apr 2018 20:52 #108405 by jason.jenkins
Mesa 7i96 options for PWM output? was created by jason.jenkins
Hello. I'm new to linuxcnc but have been able to get my DIY router up and running using the Mesa 7i96 card via ethernet with only a few hiccups along the way. I'm planning to add a laser to my router in the future which would use a 0-5v PWM signal for power control. What options do I have to make this work?

As I understand it, the 7i96 doesn't have a hardware PWM output, correct? Can one of the SSR outputs be used for a software-generated PWM signal? How about one of the pins on the DB25 expansion connector? Or do I need to add a daughter card to the board? If so, which one?

Thanks!

Please Log in or Create an account to join the conversation.

More
04 Apr 2018 21:32 #108407 by PCW
Replied by PCW on topic Mesa 7i96 options for PWM output?
if you dont need all 5 step/dir outputs, its probably simplest to steal one and use it for PWM
This would require different firmware but its a common requirement so it probably should be
made as a standard option
The following user(s) said Thank You: jason.jenkins

Please Log in or Create an account to join the conversation.

More
04 Apr 2018 23:01 #108410 by jason.jenkins
Replied by jason.jenkins on topic Mesa 7i96 options for PWM output?
I was afraid that might be the most straightforward way. Unfortunately, I'm using all 5 stepgens (dual X & Y steppers + single Z). Any other, next-best options, short of buying a 7i76e, which was my original plan, but they were out of stock at the time, and I'm impatient. :-)

Please Log in or Create an account to join the conversation.

More
04 Apr 2018 23:38 - 05 Apr 2018 00:20 #108412 by PCW
Replied by PCW on topic Mesa 7i96 options for PWM output?
If you download the latest 7i96.zip file from Mesa you could use:

7i96_5abob_d.bit

This is a configuration for that ubiquitous 5 Axis Ebay BOB on the 7I96s expansion connector.
It has a PWM output on pin 1. If you use this output, you must be careful not to short it to
power sources > +7V or < -0.5V. If you add a ~300 Ohm series resistor it will be a lot safer.

Other options are custom configs using the RS-485 XMIT data as a PWM output or another custom config using
the 5 Axis Ebay BOB as a buffer (so the PWM output would be wired to one of the BOBs step/dir outputs)
Last edit: 05 Apr 2018 00:20 by PCW.
The following user(s) said Thank You: jason.jenkins

Please Log in or Create an account to join the conversation.

More
04 Apr 2018 23:56 #108413 by jason.jenkins
Replied by jason.jenkins on topic Mesa 7i96 options for PWM output?
I'll give it a shot. Thanks!

Please Log in or Create an account to join the conversation.

Moderators: PCWjmelson
Time to create page: 0.057 seconds
Powered by Kunena Forum