The build uses an Arduino Nano as the brains of the operation, which uses its analog inputs to process incoming audio into decibel levels for display on a VU meter. It’s then charged with ...

A 40 dB sound is twice as loud as a 30 dB sound, and four times as loud as a 20 dB sound, etcetera. Zero dB doesn’t mean there is no sound at all. Rather, 0 dB is chosen as a reference level at ...

The display is calibrated in dBμ (decibel referred to 1 microvolt). The scale factor is 100mV dB–1, so that an input signal of 100 dBμ results in an output voltage of 1 V. Radio decibel meter ...