With readily available and inexpensive Infrared emitters and detectors, Infrared (IR) remotes are quite common in almost all home appliances like televisions, CD/DVD players, air conditioners, microwaves, computers, set-top boxes and stereo systems. Other benefits of IR communication are design simplicity, robustness, and energy efficiency.
The design of an IR remote comprises an IR transmitter or IR LED that emits infrared light controlled by the modulated signal from the transmitter’s MCU (microcontroller). Modulation is helpful for the detection of desired signal by the receiver in the presence of other infrared noise sources. The receiver detects the IR light using a photodiode. After demodulation is performed at the receiver, the demodulated signal is given to the receiver’s MCU for decoding. More commonly, modern IR remotes use digital modulation, for example, Amplitude Shift Keying (ASK) and Frequency Shift Keying (FSK).
IR remote manufacturers face many challenges in designing due to a wide range of IR protocols used by manufacturers of consumer electronics products. The database of IR remote control codes is continuously updated to realize designs compatible to the latest consumer products. This calls for advanced microcontrollers with adequate ROM space and some other required features. Many modern microcontrollers are targeted at IR remote applications with features such as ultra-low-power consumption, IR modulation logic and on-chip peripherals (timers, RTC, Watchdog timer, SPI, etc). The microcontroller functions to generate complex IR signals and transmit them while optimizing power consumption and software code.
Mentioned below are reference designs of IR remotes with user guides, hardware and software design files:-
- Customizable Infrared Remote Design: Here are Infrared (IR) remote reference designs to add remote control capabilities to mobile devices and consumer electronics products. Each reference design can be used as it is or can be customized to meet specific application requirements. Current reference designs incorporate Sony IR codes, Philips IR codes and a self-learning IR remote reference design. The designs perform all the necessary hardware interfacing for IR receive and/or IR transmit. The designs are fully customizable, provide applications processor interface via I2C or SPI, and performs all necessary infrared PWM functions. More on this Reference Design
- IR Remote using Ultra-Low Power MCU: This reference design implements an IR Remote Control which includes a basic Infrared TX (transmitter) and RX (receiver), and Learning Mode where the device can be trained to control existing IR devices, like a television. Based on the integrated IR features of the MSP430FR4133 device such as IR modulation logic features, the design is made simple and efficient. The design supports 38kHz carrier IR ASK demodulation, but can be modified for other carrier frequencies. The MSP-EXP430FR4133 Launchpad comes with a LCD display and an integrated display driver. Included In the design are software demo projects for TX, RX, and Learning Mode, and a design guide. More on this Reference Design
- Universal Infrared Remote: This is a Universal Infrared Remote (UIR) that sends out infrared signals to control several types of appliances such as TVs, VCRs, Satellites, Cable, CD players, Ampliﬁer/Receivers, etc. Different appliances require different encoding formats, protocols and data. This reference design is implemented using the Zilog IR controller with low-power features and the UIR database. Various IR signals are compressed and encoded into Zilog’s database format. A designer can simply call up a subroutine from the database. IR data relating to the speciﬁc key for the appliance brand and the application device are retrieved and sent out. More on this Reference Design
- Infrared Remote for DVD Player: Here is a simple Infrared Remote Control Reference design specifically programmed to control an APEX model 1201 DVD player. The design is kept simple so that user can turn it into an application specific system. The design includes a 8-pin MC68HC908QT2 microcontroller from Motorola, Infrared LED and driver, visible LED to show activity, six user push buttons, MON08 programming interface for in-circuit FLASH programming and battery holder for 3-AA cells. More on this Reference Design