Introduction: Backup Infrared Remote Codes With IR Receiver

By Taste The Code
About: Part software developer, part maker.

Hi everyone, and welcome! Today we're diving into the fascinating world of infrared (IR) technology. You might have used an IR remote without giving it much thought, but have you ever wondered how you could harness this technology for your own DIY projects? Whether it’s controlling LEDs or various devices around your home, infrared opens up a playground of possibilities for the savvy tinkerer.

The inspiration for the project comes from a worn-out remote from my aging surround sound system. Some buttons are missing and that makes adjusting the volume or tuning to radio stations quite the hassle. This spurred me on to craft a solution—a device that can capture and store the IR codes sent from the remote. This data is invaluable as it empowers us to replicate the remote's functions and even integrate them into custom projects.

In this Instructable, I'll walk you through how I built an infrared receiver to capture these codes and how we can use this knowledge to manipulate devices with our own IR emitter setup. This is a particularly useful skill for anyone looking to add a level of automation or control to their projects. So, let's get started and see this in action!

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Step 1: Wiring the Infrared Receiver Diode

To start capturing remote control codes, the first thing we need is an infrared receiver diode. I've got mine hooked up to an NodeMCU – a simple, yet effective, microcontroller unit that's perfect for these kinds of projects. Wiring the IR receiver is straightforward; it has three pins that need to be connected.

First, I provide power to the receiver. The far-right pin on the receiver is for the voltage supply. Infrared receivers typically operate anywhere from 2.2 volts to 5.5 volts. Therefore, you can connect this pin directly to the 3.3 volts pin on the NodeMCU, which is suitable for most IR receivers.

Next is the middle pin, which is for the ground connection. This pin needs to be linked to one of the ground (GND) pins on the NodeMCU.

Finally, the leftmost pin is for the signal. This pin will carry the information from the IR receiver to our NodeMCU. I have connected it to the digital input D5 on the NodeMCU. It's essential to remember this pin designation, as we'll use it later in the code to process the signals received.

With these connections — power, ground, and signal — our IR receiver is all set up. It’s a simple procedure, but it’s the foundation for all the fun experimentation we’ll be doing with infrared remote codes.

Step 2: Understanding the Code and Utilizing the IRremote Library

Now that our IR receiver diode is wired up to our NodeMCU, it's time to delve into the code that will bring our setup to life. For this project, we utilize the IRremote library, a powerful resource that simplifies the interaction with infrared signals in coding. The library supports various protocols and is extremely useful in decoding the data received from the IR remotes.

The core of the program begins with defining the protocol that our remote control uses. If you're unsure of the protocol, the IRremote library comes with example sketches that can help you identify it. In our case, we define the receiver pin as D5, which corresponds to the pin we used to connect the signal pin of the IR receiver.

In our setup code, we initiate serial communication and start the IR receiver, preparing it to listen for signals from our remote. You'll see that digital pins like D2 and D3 are set as outputs. This setup is specifically for controlling the LEDs I've attached to the breadboard for demonstration purposes.

As we jump into the loop function, the script actively listens for any signal received by the IR receiver. Once a signal is decoded, the information is printed out through the serial, showing the protocol, address, command, and the precious raw data we aim to capture. 

For a detailed code walkthrough and to see exactly how these commands work in action, please refer to the full explanation in the video above. It provides a step-by-step guide through each line of code, ensuring even those new to Arduino and IR technology can follow along and replicate the project.

The code for the IR receiver is available on my website.

Step 3: Saving Remote Control Codes for Later Use

After setting up our IR receiver and understanding the code, it’s time to back up the remote codes. This is an essential step, especially when you have an aging remote like mine, which is missing some buttons but still works perfectly for the functions that remain. The goal here is to create a digital backup of these commands, so we can eventually replicate them or embed them into custom projects.

As I begin capturing the codes, each button press on the remote results in a unique code displayed on the serial monitor. This data includes the protocol used by the remote, the command itself, and the raw signal data. It's this raw data that is crucial for our backup, as it will enable us to emulate the remote later on.

To organize the codes, I’ve compiled them into a table, listing all the buttons like Power, Mute, Volume Up, and Volume Down, alongside their corresponding IR codes. By storing every single command, I've essentially built a comprehensive backup of the remote's functions.

Now with all the codes saved, the exciting part is the potential applications. In theory, I could create a new device that emits these IR codes, or even better, integrate them with a system like Home Assistant, allowing me to control my surround system seamlessly through a centralized smart home setup.

Making a backup of these codes not only saves you from future frustrations when your remote inevitably gives up the ghost, but it also opens up a whole new world of possibilities for personalized automation.

Step 4: Programming LEDs to Respond to Remote Commands

With the captured IR codes, it's possible to add a playful and practical aspect to our project by controlling LEDs with the remote. I've set up two LEDs on my breadboard, a green one and a red one, for this demonstration. They're connected to the NodeMCU, allowing us to directly control them using the IR codes from the remote.

In my code, there's a specific section that responds to particular remote commands. For example, I've programmed the NodeMCU to listen for the 'Front Plus' button signal. When I press this button, the corresponding code is sent to the NodeMCU, triggering the green LED to turn on. Pressing the "Front Minus" button will switch it off. The same process works for the red LED, but with different buttons on the remote, 'Surround Plus' and 'Surround Minus'.

To accomplish this, I use digital pin mappings in the script, where I've assigned the green and red LEDs to different pins on the NodeMCU. Within the loop function, the decoded signal is matched to a specific case within my switch statement. If the case is met (say, the 'Front Plus' button press), the script runs a digitalWrite command to either power the LED or cut off the power, turning it off or on respectively.

Step 5: Deciphering the Remote's 'Repeat Code' Function

In the process of examining the remote's signals, I discovered an interesting quirk known as the 'repeat code.' When you press a button on the remote, it sends a single command. However, if you press and hold that same button, initially the command is sent just once, but then you'll notice a series of repeat codes being transmitted. This feature is designed so the remote can differentiate between a single press and a long press, which is commonly used to incrementally increase volume or channel numbers.

The repeat code is essentially a way for the remote to tell the receiver, "Keep doing what you just did." This can sometimes be tricky; if the initial command isn't received correctly for some reason, the receiver won't correctly process any subsequent repeat codes. It might just sit there, confused, not knowing what action to continuously repeat.

To get around this issue, if you find that pressing and holding does not achieve the desired response, it's better to release the button and press it again. This way, you resend the original command instead of hoping the receiver understood and is acting on the repeat codes.

This understanding of how repeat codes work is crucial as you develop more complex interactions with your projects. Knowing this helps ensure the reliability and responsiveness of the devices you're looking to control through IR commands, leading to a smoother and more user-friendly experience.

Step 6: Bringing It All Together

In wrapping up our exploration into the world of infrared technology, it's quite incredible to see the potential that lies within a simple remote control. We've journeyed from understanding how to capture IR codes using an IR receiver and a NodeMCU, to saving them for future reference, all the way to practically using these codes to control LEDs and potentially, other devices.

By taking apart the processes step by step, I hope you now feel empowered to tackle your own IR-based projects. Whether you're looking to replace a worn-out remote, integrate IR controls into your smart home setup, or simply tinker with a new way of interacting with electronics, the foundational skills we've covered here should serve as a robust launching point.

Remember, the beauty of DIY projects, particularly with platforms like Arduino and NodeMCU, lies in the community and shared learning experiences. If you have unique ideas on how to use these stored remote codes or run into challenges along the way, don't hesitate to share your thoughts or seek advice in the comments.

Thank you for joining me on this excursion into the invisible yet impactful realm of infrared controls. Be sure to like and subscribe for more explorations and DIY electronic projects.