You must be wondered, “Can PWM from a simple micro-controller duplicate complex sounds?” Well, if you have thought it before, then you’re very lucky, as you’re about to find out the truth by yourself!
Do you believe that by using a PWM channel of a simple microcontroller, a capacitor and a resistor, you can duplicate sounds on the fly? And, isn’t it even better, if you can have your micro play-back complex things over audio for an extremely low cost?
Ok, let’s cut the long story short and getting straight into the main topic! For this project, an AVR Mega series microcontroller will be used to control the whole system.
It transfers the stereo file 161828 baud (64 kbps of actual radio), where the RC filters is already set at a breakpoint of about 8khz. Since it’s a stereo type, thus two RC filters are needed in this project!
You might found out another interesting thing here. Although the sound can be easily recognizable, but its not MP3 quality at all!
By the way, with this Stereo PWM audio, you can store plenty of pre-recorded responses into the flash memory or an SD card instantly. This is going to save you a lot of time and money indeed!