Hi,
I have a SAM7 chip and am having some trouble understanding why my PWM behaves as it does with a speaker I am attempting to drive.
Its a 8 Ohm 0.2W speaker.
I was reading up that it was possible to rather crudely convert 8bit audio to PWM pulses and thus drive the speaker. I have attached the speaker directly to the PWM - no RC/Filter stuff going on-- I am just attempting to understand the principle.
From what I gather, modulating the Duty Cycle is supposed to change the frequency on the speaker. However all that seems to do is change the volume!
Only changing the frequency of the PWM seems to change the actually pitch of the speaker.
Am I doing something wrong?
Regards
Peter
I have a SAM7 chip and am having some trouble understanding why my PWM behaves as it does with a speaker I am attempting to drive.
Its a 8 Ohm 0.2W speaker.
I was reading up that it was possible to rather crudely convert 8bit audio to PWM pulses and thus drive the speaker. I have attached the speaker directly to the PWM - no RC/Filter stuff going on-- I am just attempting to understand the principle.
From what I gather, modulating the Duty Cycle is supposed to change the frequency on the speaker. However all that seems to do is change the volume!
Only changing the frequency of the PWM seems to change the actually pitch of the speaker.
Am I doing something wrong?
Regards
Peter