You may not think of salt and sugar as solids because when you see them in the kitchen they are such small particles. But each of these particles is as much a solid as a wooden table, a glass window, or a gold piece of jewelry. A solid is a collection of atoms or molecules that are held together so that, under constant conditions, they maintain a defined shape and size.
Pulse Width Modulation, or PWM, is a technique for getting analog results with digital means. Digital control is used to create a square wave, a signal switched between on and off.
Explanation for PWM in AVR. 1  AVR is acting as the brain of Pure Sine Wave Inverter. 2  Below is the program for atmega16 microcontroller with a clock frequency of 8 MHz (Fcpu = 8MHz). We have worked on a compiler named AVR GCC.