MAX9814 Microphone VU Meter

Whistle into an electret mic and watch eight LEDs jump in time with your voice — with automatic gain so quiet and loud both work.

Difficulty: Breadboard. Estimated build time: about 35 minutes. Estimated parts cost: about US$4.50. 8-part bill of materials with live supplier pricing. An eight-segment VU meter that displays the running peak of an electret microphone signal as a bar of lit LEDs.