Once built, you can use it as ambient light and install it behind the TV screen or on your gaming PC, even if your motherboard doesn’t support RGB or ARGB (Addressable RGB).

Things You Will Need

For this project, you will require the following:

A WS2812 addressable RGB LED strip. Get a 5-meter non-waterproof roll. An ESP8266-based MCU, such as NodeMCU or D1 Mini. You may also use ESP32 (if you already have one). A microphone module. You can choose any or whichever is available at your location. INMP401 MEMS microphone MAX4466 electret microphone MAX9814 electret microphone A 5V 3A or better power supply.

Skills Required

Soldering skill is required. However, if you don’t have any prior experience or need help in getting started, refer to our previous guide to learn how to solder.

Step 1: Download and Flash the Firmware

For this project, we will use the WLED Sound Reactive project on GitHub.

Download the WLED Sound Reactive latest stable release for ESP8266 or ESP32 board (whichever you using). Also, download and launch the ESPHome Flasher tool. Select the COM Port where ESP8266 or ESP32 is connected. Click Browse to choose the WLED firmware.

Now click Flash ESP and wait for the flash process to complete.

Step 2: Connect WS2812 to ESP8266/ESP32 Board

Once the firmware is flashed, you can connect the WS2812B ARGB LED strip to the ESP32 or ESP8266 board. You may connect the ARGB power input directly to the ESP board’s VIN and GND pins or use a separate power supply to power the LED strip separately but with common ground.

Refer to the following diagram and table to pair the RGB strip and the mic to the ESP module.

If you don’t have a power supply or don’t want to invest in one, you may pair the LED strip directly with the NodeMCU or ESP32 and power the ESP using a micro USB cable. Although this works, it may damage the MCU and thus is not recommended.

Step 3: Set Up Sound-Reactive Backlight

Once you have connected the mic and the WS2812B LED strip to the ESP board, connect the 5V power supply to turn on the device.

On your smartphone or PC, open Wi-Fi settings and connect to the WLED-AP network. Once connected, switch off mobile data and then open a web browser app, such as Chrome or Safari, on your smartphone. Visit the IP address 4. 3. 2. 1 and click Wi-Fi Settings. Type your Wi-Fi SSID and password. Click Save & Connect. The ESP will stop the AP mode and connect to your Wi-Fi network.

Open the Play Store and install the WLED app. Open the WLED app and tap the + icon. Tap Discover Lights… The module will automatically find the RGB strip connected to your Wi-Fi network. Tap the tick/check icon at the top. Then tap on the WLED-SoundReactive. This will load the control screen where you can change color, pattern, effects, etc. However, before you can do that, you must configure it.

Tap Config> LED Preferences. Count the number of LEDs after pasting them at the back of your TV or monitor and enter it in the Total LED Count field. Under Hardware setup on the same page, type ‘2’ in Pin, ‘0’ in Start, and the last LED count in the Count field. Tap Save.

Step 4: Test the Sound-Reactive LED Strip and Adjust Sensitivity

You can now control the LED strip with the WLED app and change effects, brightness, etc. You can also adjust the sound sensitivity through WLED settings based on your needs. To adjust the sound sensitivity, go to Config> Sound Settings. There are two settings available:

Squelch: The minimum threshold at which the lights will display any color or effect. The higher the value, the higher the sound pitch required to trigger the LEDs. Gain: The sound sensitivity. The higher, the more sensitive it is to sound.

After entering the values in the Squelch and Gain fields, tap Save. You can play with the settings until you get the best experience for your setup.

Under Effects, you will find 15 sound-reactive effects (marked with *). You can change to any or choose a non-sound-reactive effect. The *Noisemeter is recommended for most. You may choose your palette to change the color or create a preset using a combination of palettes and effects. Further, you can change the effect speed, intensity, and LED brightness to customize the effects.

Step 5: Integrate With Home Assistant (Optional)

You can set up Home Assistant to automate this DIY smart sound-reactive ambient light, and control effects, brightness, and other settings from a single panel. It also gives you remote access to all your smart sound-reactive ambient lights. Besides, you can enable MQTT or emulate the strip as Philips Hue (under Config > Sync Interfaces) to control the strip using the Alexa voice assistant.

Set Up Multiple WLEDs and Sync Them Together

Congratulations: you have now built a sound-reactive ambient backlight for your TV or monitor. If you want, you can set up multiple WS2812 ARGB LED strips in your room or house and sync them all (via the built-in UDP protocol support) to play the same effect simultaneously with just a few taps. These DIY strips can be controlled individually or in a group using a dedicated Android app available on the Play Store, as discussed in this guide.

You may also use voice assistants such as Alexa to control the RGB strip, change brightness, or color. Further, you can add this in Home Assistant to control all your RGB strips from a single dashboard.