Hello,
I’m having trouble setting up my jrk12v12 to actuate a 12V DC motor using a PWM input signal. I have verified with a oscilloscope that I am sending in to the jrk12V12 a 1-2ms PWM signal (4.5VDC). I see flashing red/yellow LEDS (oscillating input invalid error?) and have made sure I am in Pulse width Mode, but have not done anything with scaling or other set-up menus. I do see my PWM signal in the Config Utility Graph, but my motor is not moving.
Can someone please help guide a newbie through the proper set up?
Brad
Does the Jrk Configuration Utility indicate that you getting any errors when you look in the Errors tab?
The Input Invalid error might be caused by a signal with a period that is too long or too short. What is the period of the signal you are sending (pulse high time + time between pulses)?
–David
David,
We were using a 500ms delay between the 1-2ms pulses. I changed that to a much smaller delay of 50ms and now no errors occur. I still see no motor movement, however. I think we are closer, but still need some more help.
Brad
I discovered that I needed to turn off my feedback - it now seems to work. Can I use feed back in the PWM mode?
Brad
Yes, you can use feedback in conjunction with any of the jrk’s input modes, including RC pulses. It probably didn’t work for you because you forgot to set any PID parameters and they are all 0 by default. See the “Setting Up Your System” section of the user’s guide for tips on how to choose good PID parameters:
https://www.pololu.com/docs/0J38/5
Please also see the FAQ entitled “Why is the jrk not driving my motor?” on this page:
https://www.pololu.com/catalog/product/1392/faqs
–David
David,
Thank you. I set the PID to 1,0,0 as described in the link and it now works. I will read up more on the info you provided.
Brad
