Oscillator design using a microcontroller

[rahul.6sept]

Dear all,

I want to design an oscillator using a pic 32-bit microcontroller. Now microcontroller does have inbuilt oscillator. hence designing oscillator using mc , is it worth?

rahul

 

[kripacharya]

Using the internal oscillator of a uC in the way you are thinking is not a great idea, since you will get very limited range of frequencies.

You should instead investigate oscillators based on DDS concept. (Direct Digital Synthesis)
Here is a good introduction to this.

And here is a **broken link removed**

Once you understand the basic concepts, you can design your own.

 

[horace1]

DDS is the simplest way to get a wide range of accurate frequencies chip interface typically being SPI or parallel
another good introduction is
https://www.analog.com/library/analogdialogue/archives/38-08/dds.html

 

[rahul.6sept]

Can I design a nonlinear oscillator (duffing oscillator) using dds technique?

 

[kripacharya]

Can I design a nonlinear oscillator (duffing oscillator) using dds technique?

Sure why not. You will need one module to generate the frequency, and another module to manage the amplitude.

 

[rahul.6sept]

In the digital phase wheel (in the tutorial) how the bits are changing at each designated point?

rahul