04-22-2009 10:35 AM
Hello!
I'm trying to generate PWM output signals with the MCB 2300 Board and LabVIEW for ARM 1.0. Unfortunately some problems occured:
-If I use the PWM1 output, no signal is generated
-If I use other PWM outputs, a signal is generated, but changing the frequency in the property dialog has no effect
-Every PWM output has got a different (constant) frequency
-If I use two PWM outputs in a VI, the output signals change in a strange way subject to the input values (Sometimes only one correct singnal, sometimes two signals, but wrong duty cycle value)
I'm working in a generic project, the problems occure in a MCB2300 project, too.
It would be very nice, if anybody outthere could help me!
Greetings,
Joscha
04-23-2009 03:32 PM
Hello Joscha,
i have tested this with LV 8.6 and Arm Kit 1.1 everything works fine.
I have added my project as zip file. There is a difference, if you put
other numerics into the PWM output. You must put in all outputs the
same numeric so the additional seetings from the frequency take an effect.
Do you use Port 2 also as an input or output for LED`s or KEY´s that
doesn´t work. How dou you measure the different duty cylces in
my project you can see it on the brightness of the LED´s.
best regards ALEX
04-23-2009 03:33 PM
Hello Joscha,
i have tested this with LV 8.6 and Arm Kit 1.1 everything works fine.
I have added my project as zip file. There is a difference, if you put
other numerics into the PWM output. You must put in all outputs the
same numeric so the additional seetings from the frequency take an effect.
Do you use Port 2 also as an input or output for LED`s or KEY´s that
doesn´t work. How dou you measure the different duty cylces in
my project you can see it on the brightness of the LED´s.
best regards ALEX
04-24-2009 04:43 AM
Hey Alex!
Thanks for your message. Unfortunately I can't open your project, because I'm working with older version of LabVIEW (8.5) and LabVIEW for ARM (1.0).
In my project I'm only using PWM outputs, so there can't be a conflict with other elemental I/Os. In other projects I could use the LED-functions without problems, even LED0, although PWM1 doesn't work at all.
I'm displaying the output signals on an oscilloscope to get information about duty cycle aund frequency.
Best regards, Joscha
04-24-2009 04:54 AM
A question to the forum team:
Would it be possible to move this thread to the correct part of the forum (LabVIEW embedded)? Unfortunately I didn't choose the right option, when I was posting the question.
Regards, Joscha
04-26-2009 02:42 AM
Hello Joscha,
i have make an pictre of my test programm, and here is an link about the offset and the duty cycle.
http://digital.ni.com/public.nsf/allkb/839DB5B54A0915A9862574D70063B64B
In my application the pwm signals start at the same time.
I hope it helps, if not please show me your code.
best regards ALEX