[PIC] low frequency sinewave

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microlab

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hi friends

can anyone help me to make a sine wave of 6 Hertz with pwm?
i am using 16F886 with 16MHz crystal(any crystal can be used)
how to decide the pwm frequency and look up table ?

regards

mL
 


dear horace1

thank you for the reply
is it not possible to generate such low frequency sine wave with built in pwm module and look up table?

regards

mL
 

microlab said:
dear horace1

thank you for the reply
is it not possible to generate such low frequency sine wave with built in pwm module and look up table?

regards

mL
Click to expand...

I don't know - never tried such a low frequency using PWM i always used DDS chips

if i have time i will try it out
 

is it not possible to generate such low frequency sine wave with built in pwm module and look up table?
Click to expand...
Of course it's possible. PWM frequency is primarly independent of sine frequency, except for the fact that it must be high enough to be filtered with acceptable effort.

The sine generation will be basically identical either if you use PWM or a DAC for analog output signal generation. You have to decide for a table size and word width based on signal quality requirements and available PWM/DAC resolution. For the table index generation, a NCO/DDS scheme as suggested by horace1 will be beneficial in any case, particularly because it offers effectively unlimited frequency resolution.
 

dear FvM and Horace1

thank you for the suggestions
i will try it

regards

mL
 

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