Applications of PWM in IoT are controlling the speed of DC motor, Controlling the direction of a servo moto, Dimming LED, etc.
Pulse Width Modulation (PWM) controls analog circuits with a microprocessor’s digital outputs. In this technique, Digital-to-Analog conversion is not necessary as the noise effects are minimized by keeping the signal digital. In PWM technique the energy is distributed through a series of pulses rather than a continuously varying (analog) signal. By increasing or decreasing pulse width, the energy flow to the motor shaft can be controlled.
Fig. 1 – Pulse Width Modulation (PWM) Waveforms
Fig.1 above shows Pulse Width Modulation Waveforms with different duty cycles. The proportion of time that the pulse is ‘ON’ or ‘High’ is called the Duty Cycle.