What is PWM and what are its applications?

PWM (Pulse Width Modulation) is a technique to encode analog values in a digital signal by varying the duty cycle (ratio of ON time to total period). Key parameters: Frequency (how often the cycle repeats). Duty cycle (percentage of time signal is HIGH). Resolution (number of discrete duty cycle steps). Applications in embedded systems: Motor speed control (DC motors, servos). LED brightness control (dimming). Audio generation (buzzer, DAC replacement). Power regulation (SMPS, buck/boost converters). Signal generation (for testing, communication). Implementation uses timer/counter peripherals with compare registers. Higher PWM frequency reduces visible flicker (LEDs) and audible noise (motors), but may reduce resolution.