Feature:1. DC voltage between 5V and 12V can be powered, with reverse connection protection.2. The VU meter is a voice‑activated sensor, so there is no need to connect audio, just power on the product, it will flash when there is a sound.3. The louder the sound, the more the LED will light up from bottom to top. As the sound fluctuates, the LED will flashing with the music.4. Using an independent comparator circuit, although the circuit is slightly more complicated, the structure and principle are easier to understand.5. Equipped with anti‑reverse connection protection diode, which can effectively prevent the circuit from being burnt due to the reverse polarity of the power supply.How to Use:Regarding signal input: The board comes with a microphone, no need to connect an audio signal, it can sense and receive an external sound source, and control the blinking of the LED lamp beads. The disadvantage is that the sensitivity is not as good as the line input, and it is easily affected by other external sounds.If you need line input, this step is about the audio signal (for example, the headphone power amplifier of a mobile phone or computer cannot be connected to the output of the power amplifier or the speaker), you can remove the microphone, and the signal is introduced directly from the&nb