In the 1980s, there was no internet as like today and so the sources of entertainment were televisions, radios and cassette players. When I was a kid, we had an audio cassette player. We used it to play songs but my imagination was always fixed to its VU meter display with its fancy readings as shown below. It changed with the volume of the speakers and matched rhythmically with the sound coming out of it. During my engineering career, I got to know about the Decibel scale and sound pressure measurement. It soon became a goal for me to design an audio dB meter and recreate my child memories. In this tutorial, I will show how to make a dB meter that is accurate enough for general uses.
This Arduino-based sound direction locator uses a Pac-Man like ghost that runs towards the direction of the origin of sound. It uses three microphones amplifier modules arranged in a triangle to locate the direction of the sound and an 8×8 LED grid display for output. The Arduino Uno senses the incoming audio levels from the three microphones and moves the ghost in the direction with the loudest sound detected by turning on the appropriate LEDs on the grid.
Arduino sound direction locator
Check out this video showing it in action.
A clap switch is a fun project for beginners. It switches on and off electrical appliances with a sound of clapping hands. Today we will discuss about making a simple clap switch that operates when it detects two clapping sounds in a row. It uses an electret microphone as a transducer for converting a clapping sound into an electrical signal. The microcphone output is amplified by a transistor and is then sent to the PIC12F683 microcontroller which performs an ON/OFF switching action when valid claps are detected.
Simple clap switch using a condenser mic and PIC microcontroller