Understanding IR Controllers and Their Role in Remote Control of LED Displays

Controlling LED displays manually can be quite exhausting. Aside from that, this approach can prove to be limiting in many ways. These concerns validate the need for wireless IR controllers. In this article, we cover everything you need to know about IR controllers and their role in controlling the use of LED displays.

What is an IR Controller?

IR is an acronym for Infrared, which is a technology that uses light to transmit data signals in a split second. This light exists in the infrared spectrum which is not visible to the naked human eye. 

An IR controller is a device that emits infrared light, sending signals to a display. A TV remote is a good example of an IR controller. When a button in the remote is pressed, the device (display) receives information and acts in response to the data in the signal.

The term IR controller is used as an umbrella to represent all devices that send infrared signals to a device and control its functions. However, not all remotes use IR signals.

Another common type of remote control is known as an RF (radio frequency) controller. This type of remote uses radio signals to transmit data to the target device. Radio waves are known to travel through obstacles. As such, RF controllers do not require a clear line of sight to function. Therefore, RF controllers are considered more efficient than their counterparts.

How an IR Controller Works 

The way IR controllers work is by encoding tidbits of data in the light. An on-and-off flash encoding technique is used. This might sound too complicated but it simply means when the light is on or off. In the first instance (ON), the IR controller can transmit data while that functionality is disabled in the OFF state.

Unlike some devices such as smartphones, the IR controller does not have a blaster. The blaster is a device that is added to high-end gadgets such as smartphones to enable them to function as an IR controller. Moreover, IR controllers send light signals in a straight direction while IR blasters can send in multiple directions. 

Standard IR controllers send these light signals using an LED bulb. This LED bulb is not the regular type since it does not produce visible light like others. This LED transmits the infrared light to the device and the device reacts accordingly.

On the other hand, the LED display has a receiver that decodes the signal contained in the infrared light. This sensor is usually located on the front base of the LED display. This placement is essential to ensure that the unidirectional signal is transmitted efficiently.

Modulation Schemes Used in IR Controllers

There are three main methods of signal transmission by IR controllers. These methods are technically known as modulation schemes. More specifically, modulation is the process of assigning the signal a pattern so that the receiver can perceive it. 

The objective of signal modulating is to ensure that the receiver in the LED display can single out the particular signal coming from the IR remote. This is important since it ensures that your display cannot be controlled by a foreign device. Also, it helps the IR receiver in the display to ignore the ambient light. Let us learn more about these modulation schemes.

Pulse Width Modulation (PWM)

IR signal transmission is enabled by short-range control protocols. For this to happen, the devices (ie TV remote) encode data in the form of pulses of light. Each light pulse has a duration that it lasts. The pulse is denoted as either short or long based on its duration. As such, a light pulse can be said to be binary.

In pulse width modulation, the IR receiver detects the variation of the light pulse to make out the pattern in the signal. Again, the pulse can either be short ‘0’ or long ‘1’. The receiver in the LED display detects these variations and decodes the signal data.

Manchester Encoding (Bi-phase encoding)

This modulation scheme applies a similar logic to PWM. However, it differs in the technicalities of the process. 

In Manchester Encoding, the concept of bits is introduced. Bits are divided into equal lengths with one half being the pulse mark and the other one a space. The first half is represented by the binary digit 0 while the space is represented by 1. 

During the signal transmission, the transition from low to high or high to low is represented by the ‘0’ digit while 1 means no transition. This modulation technique is efficient since it ensures that the on and off states are translated properly.

NEC Protocol

Unlike in PWM where the device uses a pulse length protocol, the NEC protocol uses the pulse’s distance in the decoding. 

In this scheme, the pulse is transmitted in timed intervals. More specifically, the signal carries a binary code that the receiver translates according to the intervals between pulses. The PDE is an efficient technique since it ensures swift signal transmission and decoding.

These modulation techniques have not been explained completely in this article. There are many technical details that are entailed in each process. For this article, these details would be irrelevant so they have been left out. All the same, you have a basic understanding of the modulation techniques and how IR controllers use them to communicate with LED displays.

What Makes up an IR Controller?

There are two main components of an IR controller — the circuit board and the LED. The two function concurrently to relay signal data to the IR receiver in the target device. Here are more details about the two components.

IR Transmitter Circuit

In electronics, the ‘brains’ of any device are located on the circuit board. This board contains different sub-components that work together to bring out the functionalities of the device. The components will differ based on the use of the device.

IR controllers have a transmitter board that contains three main components. They are;

  • Oscillator. This component is responsible for generating the carrier frequency of the remote signal. The signal of most IR controllers is transmitted at a frequency of 38 kHz.
  • IR LED driver. The LED light, which is the other major component of the IR controller, needs a driver to control the current required to light it up. This is the function of the driver.
  • Modulation circuit. Remember the modulation schemes we discussed above? This circuit is responsible for generating the specific scheme. The scheme to be used depends on the receiver’s complexity, and data rate, among other factors.

The transmitter circuit is quite simple but efficient. This is one of the main reasons why IR controllers are rather inexpensive. 


Without the LED, the device would not be able to transmit the signal. Therefore, the LED is the most essential component of this device.

The LED (light-emitting diode) used in IR controllers is somewhat different from the standard LEDs we all know. For one, it does not have the capability to produce light in the visible spectrum but only infrared light. In other words, these LEDs are engineered specifically to emit light with a specific wavelength in the electromagnetic spectrum.

IR LEDs can only emit light unidirectionally. While this limits the flexibility when using IR controllers, it makes a strong case for point-to-point communication. The IR LED is typically placed at the front of the IR controller for better performance.

What Facilitates IR Signaling on an LED Display

In the target device, there are components that act as a link between the IR controller and the device controller. The two systems have to have a seamless connectivity for the control functions to take place. For an LED display, the main components are;

IR Receiver/Sensor 

The sensor or receiver is the primary component that facilitates IR signal decoding. It is a tiny electronic device that is usually located on the front-most part of the display. More specifically, it has a spectral sensitivity of wavelengths within the 780 nm range.

IR signal sensors are broken down into types based on the technique used to detect the signals. The most common types of sensors are;

  • Phototransistors – These sensors are sensitive to light and they detect the light as it is.
  • Photodiode receiver – A photodiode is essentially a photo-sensitive diode. They work by converting a light beam into an electric signal.

Apart from detecting the IR signal, the sensor is also tasked with signal decoding. Signal decoding is the process of translating the encoded data into actionable data that the display understands. By understanding the modulation scheme used, filtered signal, and other parameters, the sensor helps the display make sense of the signal. 

The light signal coming from the IR LED can contain noise due to the ambient infrared. This means that it can be affected by flickering light and hence distorted. In most cases, the modulation schemes are able to take care of such issues. However, some spillage occurs. Therefore, a signal-filtering system needs to be in place.

IR sensors are equipped with signal filters to reduce signal disturbance that can emanate from ambient lights. These filters enable the sensor to focus on the specific signal that is sent from the IR transmitter.

Indicator Lights

Some LED displays have indicator lights that show when there is a successful signal relay. For instance, when the LED TV is turned on using a remote, the indicator light turns from red to green to show that it is on. Then the display screen turns on.

Indicator lights are also made of LEDs. However, these LEDs are the standard kinds and not the same as those used in IR controllers. They are essential because they provide you with instant feedback when using your device.

Functions of an IR Controller

Controlling devices manually takes a lot of work and effort. This is the main reason why IR controllers or remotes were invented. Also, the manual control is limited to very few functions supported by the physical buttons. The controllers expand controls and make the actions effortless. 

The functions of an IR controller are tied to the type of display and its abilities. Hence, there can be as many or few depending on this. Here are some common control functions of IR controllers.

Turning The Display On or Off 

For most users, this is the main thing they do with an IR controller. Using this device to turn on the LED display is quick, easy, and efficient. While most displays come fitted with a physical power on and off button, the remote does it better. Moreover, this button can get spoiled when used so frequently. 

Adjusting The Display’s Brightness 

Most LED displays have brightness adjustment settings. Using an IR controller, you can increase or lower the brightness of the display. This function helps maintain the brightness of the display at a reasonable level to improve the visual quality. Such a function would be quite challenging to execute manually.

Changing the TV Channel

Switching from one channel to another is also a function that IR controllers have. All TV remotes have this functionality. Whether the TV is getting the channel from an internal or external source, the remote will be able to change them easily.

Changing Input Sources

A display can have multiple input sources connected to it. For instance, it could be connected to a computer, a DVD player, or another device. An IR controller is equipped with buttons to perform the switch.

What happens with IR controllers is that every button is programmed to perform a specific function when pressed. For instance, the remote has a power button that powers the display ON or OFF. To facilitate this, the circuit board automatically encodes this data and sends it to the IR sensor in the display for decoding.

Features of an IR Controller for an LED Display

The design and specifications of an IR controller influence its efficiency. Everything from how it looks, feels, and works is part of the factors that contribute to its capabilities. Let us discuss some of these features.

Ergonomic Design

Safety and ease of use are the core principles of ergonomics. As such, when something is said to be ergonomic, it means that the user is satisfied and safe. 

Most IR controllers are designed to be long and small to fit perfectly on a human hand. They also have a grippy surface, resting grooves, and other supporting features. While they may appear subtle, these features are vital. They stop the hand from straining some muscles which can cause issues like Carpal tunnel syndrome. Ensuring that the controller is ergonomic will alleviate the chances of experiencing threatening conditions like CPS.

Customizable Buttons

Modern IR controllers are programmable. The buttons can be customized to perform specific or multiple functions. This is on top of the default or factory functions that are enabled. Such flexibility is quite helpful in many ways.

For one, a customizable remote means its functionalities are not limited. When one button can be used to initiate multiple commands, it opens up a world of opportunities. Customizability is both a feature and an advantage of IR controllers.

Fast Response Time

Electronic devices that are responsive tend to make work easier. It is quite frustrating when trying to operate a device that has a slow response time. 

Response time is defined as the time taken for the desired action to be executed. How well the buttons click and control the display. A slow response time will have you clicking one button multiple times for it to function. On the other hand, fast response controllers are swift and efficient in signal transmission.

The quickness of an IR controller is influenced by many factors. One of these factors is the circuit board of the remote. If it has faulty connections, the remote is going to struggle to pick up commands and execute them. Also, the technology of the controller has an influence. Typically, modern IR controllers have a fast response time compared to classic ones.

Universal Remote Capability

Another feature of some IR controllers is the ability to control multiple displays. The remote can send different commands to different devices and these devices would decode them separately. Such a feature is helpful for people looking for efficiency and reduced clutter.

A universal remote functions like a regular one but it has specific components and programs to enable universal usage. They have pre-programmed codes that enable them to communicate with different IR sensors. Depending on the designer of the remote, it can either detect the device automatically or manually.

There are other many specific features of this type of remote that help it execute its commands with so much ease. As such, they make the remote a must-have addition to your collection of useful devices.

How IR Controllers Differ from Other Types of Remotes

Generally, there are two types of controllers — radio frequency (RF) and infrared (IR) remotes. Simply put, a remote can send a signal as infrared light or a radio frequency. This is the major basis of comparison for the two types. Still, there are more differences between them, including;

Communication Technology

Infrared communication is different from radio. Primarily, IR uses light as a communication medium while RF uses radio waves. We discussed that the light used in the IR controllers has a long wavelength (700nm – 1mm) and is invisible to the human eye. Radio waves on the other hand are a series of repeating waves with peaks and valleys. Moreover, these waves have the longest wavelength in the spectrum.

Radio frequency controllers have an RF transmitter while IR ones have an IR LED. Also, both have different modulation schemes for data encoding. These variations are due to the differences in signal transmission and technology type.


Without additional information, you would not be able to differentiate an RF from an IR controller by simply looking at them. You would be required to operate them to see the difference in functionality. 

One thing to keep in mind is that radio waves travel long distances and they penetrate almost any blockage. This is unlike IR signals that require a plain path to the receiver. As you can tell, RF controllers allow for more flexibility than IR controllers. Still, the general functions of the remotes remain similar. 

Distance and Angle From LED Display

When using a remote control, we typically point it to the display. The distance and angle from our position matter depending on the type of remote. 

For IR remotes, the distance has to be short and from a direct angle. This is to allow for the IR signal to be directly in line of sight with the receiver. If these signals are blocked, the controller will struggle to reach the IR sensor.

RF remotes are not affected by distance or angle. Again, radio waves can penetrate any surface due to their long wavelength, high energy, and signal strength. This means that the remote can be used from any corner or location as long as the LED display is within reach. Therefore, if you were going to choose, an RF controller would serve you better.

Display compatibility 

The compatibility of an LED display with a controller depends on several factors. Factors like the display technology, specifications, and type of sensor determine the compatibility. 

Compatibility also implies the level of connectivity between the controller and the remote. In most cases, the RF remote will be more compatible than IR. This is because of the communication module applied in RF controllers.

Since some controllers are programmable, the compatibility can be enhanced. Most universal remotes have a ‘learning’ capability where they internalize the codes in their programming to improve compatibility with the target device. This improves the overall display compatibility of the remote.

Benefits of IR Controllers

Infrared technology is quite beneficial in many ways. It is among the most useful technologies even outside the bounds of remote controls. These benefits can be seen in some of the gadgets that use IR technology. The best example is IR controllers. 

They are User-friendly

Technology needs to be user-friendly to cater to the diverse user base. Since LED displays are used virtually everywhere, it makes sense for them to be user-friendly. This means that they can be operated by anyone without requiring training. This includes children who do not have much knowledge about technology.

User-friendliness is also represented by some of the features of IR controllers. Case in point, the ergonomic design of remotes makes them feel right in the hands. Additionally, most TV remotes have a simple user interface that is straightforward. In return, the user will want to keep using it for this convenience.

Compatible with Many Devices

As we discussed earlier, multi-compatibility is a good thing. Devices that are compatible with a range of systems have many benefits. For instance, it means that you will not have to buy a remote for all your displays. If one remote is misplaced, you can continue using the universal controller. This improves your user experience.


It would be unimaginable to control a display without a remote. This is why IR controllers are quite convenient. They help you operate the device without pressure and from the comfort of your sitting arrangement. This level of convenience is taken for granted but it should not be.

Limitations of IR Controllers

On top of being so convenient and beneficial, IR controllers have a number of limitations. Most of these limitations are avoidable with the right approach but it’s still worth mentioning them. They include the following;

Signal Interruptions by Blockages Are Inevitable

Unlike RF signals, IR signals require a clear path to be detectable by the sensor. As such, this means that when using an IR remote, there needs to be no obstacles for it to be efficient. Blockages and obstacles can also be ambient light apart from being solid objects. These elements interrupt the signal and hence stop the communication.

This limitation can be avoided by ensuring that the remote is used in open spaces where there are not a lot of interruptions. Avoiding them is the primary solution to ensuring a perfect communication interface between the transmitter and sensor.

Short Signal Range

Woman switching the channels on the TV.

With the short wavelength produced by the IR LED, it is expected for the transmitter to require close proximity to the sensor for the communication to occur. Therefore, the IR controllers have a short signal range. 

Again, ensure that you are close to the display, preferably pointing towards the sensor location, for fast signal pickup. This is guaranteed to improve the efficiency of the system by far.

Easily Interfered with By Other Signals

Ambient lighting produces light signals too. While the IR transmitter works with specific modulation for efficient communication, sometimes the encoding and decoding programs can be overwhelmed by ambient lighting signals.

One way to avoid these occurrences is to ensure minimal lighting that can affect the performance of the IR controller. This includes too much LED lighting. Alternatively, ensure that the controller is of high quality and modernized to handle these variables.


IR controllers are essential peripheral devices for LED displays. Their features, functionalities, applications, and benefits are unimaginable. All this for a simple device that uses infrared technology to communicate with other devices. This article has demonstrated that they are a must-have for your home or office. 

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