pwm modulation on blackfin

[Karunya_R]

Hi Eyal,

I am going to answer all your bullet points.

You said " I'm downloaded the datasheet of ADSP-BF537 EZ-KIT. From that I'm understand that I'm can't work with TMR0 and LED4 in the same project."

You are right. You cannot have LED4 and TMR0 in the same project. As I said in my post on April 2nd, if you use the PWM functions with your VI, you can't use the LED functions there simultaneously as it would lead to a conflict.

You said "What I'm mean in my question is why I'm see the signal that generated to TMR0 only on LED4, and not between pins 6 and 9 on header P11. The signal was checked by oscilloscope."

As I said on my April 2nd post, you can not have your LED light up and your PWM send a signal to the header on P11. From what you are saying, it sounds as though you are able to see the LED light up and not getting a signal in your P11 Header. Ensure that you are setting the polarity of the LED to negative.

You said "Following your request to measure the execution time of FOR loop by using flat sequence and timer, I can't do it because in working with BlackFin, labview compiling the VI and downloaded him to the RAM of EZ-KIT, and the VI looking like freeze (not on running mode) and I'm doesn't see any change on indicators. To demonstrate this operation, I'm measure the time of steps on one cycle of output signal. Attached image from oscilloscope, you can see that the time of one step (is equal to one iteration of FOR loop) is around 1.7 msec. "

I can see what you mean about the 1.7 msec iteration. When you run your VI, there should be a processor status window which says that the program is running. The indicators will update on debug mode. So please ensure that you are running your VI on debug mode to see the indicators update on the front panel.

You said "My main question is how to increase the iteration cycle of executed FOR loop, or any other suggestion to create modulated PWM by sinusoidal signal with adjustable frequency of sinusoidal signal (at range of 10-100Hz)."

Does this mean that you want to reduce the 1.7ms iteration to something lower than that?

Or does this mean that you want to increase the number of times this loop runs?

I look forward to your reply.

Thanks,

Karunya R

[Karunya_R]

Hi Eyal,

Any luck with this?

Thanks,

Karunya R

[MeghanK]

Hi Eyal,

This is Meghan from National Instruments. I wanted to check on the current status of this issue with PWM modulation since we had not heard back from you in a couple of months. Have you made any progress since your last post? Please let me know if you are still having problems creating a modulated PWM so we can work with you to resolve your issue.

Thanks,

Message Edited by MeghanM on 08-31-2009 05:04 PM

[freitas]

Signals in LED's CAN be viewed in Connector Stamps.. review all DIP Switches (though I don't remember seeing one to disable TMR0)!

To comunicate with your PC, I recommend SPI and UART example... remove the SPI part!

One last thing.. can't u use BF PWM Write, on the Blackfin Pallete?

Best Regards,

António Veríssimo de Freitas