IR Remote Control Decoder
Created: May 19, 2016
No description available.
The first concept and invention of remote control by Nikola Tesla gives birth to the new era of wireless communication systems. Controlling devices wirelessly needs a receiver/decoder to decipher the signal or code being transmitted. The reference design is an IR remote control decoder using PIC16F57 microcontroller. The PIC16F57 from Microchip Technology is a family of low-cost, high-performance, 8-bit, fully static, Flashbased CMOS microcontrollers. It is equipped with special features that reduce cost and power requirements like power-on-reset (POR) and device reset timer (DRT) that eliminate the need of external reset circuit.
The IR communication is a line of sight communication, which means the transmitter must communicate without obstacle to the receiver. Typical IR signals that used by remote controls has three layers. In this reference design they are called infrared, modulation, and serial data. IR layer means the transmission of raw data, serial data is the raw data and modulation is the process to modulate that raw data. In this reference design, there are two receivers for the IR signal, in which a switch is used to toggle between the two receivers depending on what IR signal is received. The modulated signal is catered by one of the following receiver GP1U521Y or LT-1060, from Sharp and LiteOn, respectively. The modulation process that has frequency between 32.75kHz and 56.8kHz in this design is done to diminish the effects of ambient light, extending the remote control’s battery life and reducing the cost in making the device. For non-modulated IR signal, the QSE157QT is being used. The PIC16F57 is used as the main component for this design for it is suited to store a lot of signal lengths for later reading. For proper clock timing and adequate frequency accuracy to determine pulse and gap lengths, the design uses a 4Mhz ceramic clock resonator. To reset PIC16C57, a push button is available and four jumpers are provided to control the application startup. The two-digit display is driven with Q1 and Q2 and three octal switches are used as inputs to control OPTION register and which file will be displayed. The circuit is powered by 5V output regulated by U1 from a 9V, 200mA supply.
The infrared communication is still the most suitable for short distance communication. The application of IR communication employs safety especially in industrial works. It also lessens the physical contact to the machines with hazardous environments.