Remote infrared Sensor

Remote infrared (IR) works by transmitting invisible infrared light signals from a remote control to a receiving device, such as a TV, air conditioner, or home theater system. Here’s a breakdown of how it works: **1. Infrared Light Transmission** • The remote control has an **IR LED** (Light Emitting Diode) that emits infrared light when you press a button. • This light pulses at a specific frequency, typically around **38 kHz**, to avoid interference from ambient light. **2. Encoding the Signal** • When you press a button, the remote’s microcontroller encodes the command into a digital signal (a sequence of ON/OFF pulses). • This signal consists of: • **A header pulse** (to signal the start of transmission) • **A series of data pulses** (representing the button pressed) • **A stop pulse** (to mark the end of the command) • Different manufacturers use different encoding protocols, such as **NEC, RC5, or Sony SIRC**. **3. IR Reception** • The receiving device has an **IR sensor** (also called an IR receiver module), which detects the modulated IR pulses. • The sensor demodulates the signal (removes the 38 kHz carrier frequency) and sends the raw digital data to a microcontroller. **4. Decoding and Execution** • The microcontroller in the receiving device deciphers the received data and determines which button was pressed. • It then executes the corresponding action, like increasing the volume or changing the channel. **5. Limitations of IR** • **Line-of-sight required**: IR signals cannot pass through walls or solid objects. • **Limited range**: Usually around **5 to 10 meters**. • **Interference**: Sunlight, fluorescent lights, and other IR sources can interfere with transmission.