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Hi Martijn,
This behaviour is simply how it is implemented; the pulsewidth remains constant, rather than the dutycycle.
However, I think the behaviour you are expecting is actually more desirable/natural, so I think we should perhaps revise the specification and implementation to:
Does that sound more appropriate? If so, i'll put that on our list for the next release.
Thanks for the Terminal hints. I've added your suggestion and also Putty to:
Thanks,
Simon
Hi Simon,
Thanks for the explanation! It made me scratch my head in bewilderment I must admit.
Yes the proposed behaviour sounds more appropriate. I can't offer a rational explanation right now, frequency/period just has a more 'solid' feel to it.
And Igor, thanks for thinking with me!
Regards, Martijn
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Hi guys,
I've got a question. This program kept me wondering why I see two different duty cycles after setting the PWM period.
//Fiddling with the mbed PWM #include "mbed.h" PwmOut led(LED1); Serial pc(USBTX, USBRX); // tx, rx int main() { pc.printf("testing...\n"); //testing serial port led.write(0.5f); //output duty cycle percentage (float) pc.printf("LED duty cycle is %f\n", led.read()); led.period(1.0f); //PWM period in seconds (float) pc.printf("LED duty cycle is %f\n\n", led.read()); }Output:
Am I missing something? Why doesn't the duty cycle stay the same?
Off topic: another handy terminal application is Terminal by Bray. Worth including in the Handbook?
Link
Screenshot:
Thanks!