Two PIC SW inter-modulator

[Thomas Grant]

I need to amplitude modulate the audio frequency output from one
16F28A PIC with a subaudio frequency from a second one. Both are PWM
generated sinewaves.

What is the simplest way to do this with external components?

Variable modulation depth would be useful if there's not much extra to
it.

Any advice would be much appreciated.

Thomas Grant

 

[[email protected]]

I need to amplitude modulate the audio frequency output from one
16F28A PIC with a subaudio frequency from a second one. Both are PWM
generated sinewaves.

What is the simplest way to do this with external components?

Variable modulation depth would be useful if there's not much extra to
it.

A PWM sine wave is easy to write code for. But did you know that it
wouldn't be too much harder to write code that generated a PWM sine wave at
different amplitudes? If you did that, you'd only need one PIC to get what you
want and variable depth of modulation too.

Jim

 

[[email protected]]

If you had to do it in analog, take a look at AD633 from analog
devices.

Steve Roberts