Working Of Arduino IR Sensor
Today infrared technology is used in a wide range of applications including communication as well as sensing distances without touching the surface. The infrared or IR communication system is considered as one of the most inexpensive: common and easy alternatives for the technology of wireless communication. Though the ray of IR light is similar to any visible light but still it is not visible to the human eye.
It can be used perfectly to communicate wirelessly. For instance, you can easily turn on and off your TV remotely just by pressing the button of an IR LED on its remote control which is received by the IR sensor on your TV at a very fast frequency approximately 38,000 times/second. In this write-up some basic information of IR communication system and receiving and transmitting IR data by using Arduino is provided for your consideration.
At first you will know how to use an IR photo sensor to read incoming IR data from a remote control after that you will know about controlling the device by transmitting the data from an IR LED.
You can find a number of IR resources around you like light bulbs, sun or various other appliances emitting heat with bright light. The remote control of your TV transmits information to your TV through IR LED which is received by the IR receiver in your TV to turn it off or on. In order to understand the working of your TV remote control you should know that IR signals are modulated which can be followed by the receiver of your TV. The commonly used frequency of the modulation of these communication signals is 38 kHz or 38,000 Hz/second.
The IR LED transmitting signals through Arduino IR sensor blinks very fast in a fraction of a second when you press a button of your remote control to transmit the encoded signal to your TV. This transmitted modulated signal is perfectly the same as seen by your receiving device. These signals are demodulated by the sensor at the receiving end to produce waves in binary form to be read by microcontroller of the device. The input pin of the microcontroller can read the wave form by controlling the space between transmitted and received signals and can be decoded a bit like a serial stream. Thus, a microcontroller can be connected at any of the ends of the system to receive to transmit the data.
Arduino IR sensor can also be used to set up certain types of circuits like a circuit to demodulate the IR signal received from a commonly used remote control by using photo sensor as well as the circuit to transmit IR codes to an appliance like TV or Stereo by using resistor to limit the current and IR LED. But to complete the procedure accurately it is necessary to connect the LED appropriately. Thus IR technology can help in establishing communication between the IR LED of the remote control and the IR sensor of the device to turn the device off or on even without touching it physically.