Looking for a soundpressure level metering in dbA
I already searched but was unable to find any Sound Pressure Level (SPL) metering project.
I am in the need to measure the SPL in dbA. It does not need to be that exact but should be that sensitive to see relative loudness changes.
Already tried some Arduino code that uses FFT to weight the level, but this is not very sensitive as the FFT is to slow. So the circuit should use a hardware A weighted filter.
I could create a circuit with a electret microphone, some opamp to amplifier the signal and an a-weighted frequency filter. And some other opamp and a capacitor to capture an analog voltage from that all. But I am looking for ready-to-use projects now.
Anyone already did this?
Remember I searched for something similar a couple of years back but couldn't find any hardware that did the fourier transformation. Would've been nice with some turn key sensor that reported sound pressure in dbA.