DIY digital VU meter with analog vibes

A quantity unit (VU) meter is a straightforward gauge that signifies the amplitude of an audio sign, so increased decibels transfer the needle additional. They’re widespread within the discipline of audio engineering and music manufacturing, with conventional VU meters being analog. However tuning an analog gauge is a problem, so Mirko Pavleski designed a VU meter that looks analog and comes with all the advantages of a digital system.

Monitoring the amplitude of a sign (like an audio sign) with a microcontroller may be very simple — if that microcontroller has an ADC (analog-to-digital converter). MCU processors solely perceive digital ones and zeros, so the ADC is critical to translate an infinitely granular analog sign into digital values that approximate it. The Arduino Nano board has eight analog enter pins monitored by the ATmega328’s ADC and this venture makes use of two of them: one for the left audio channel and one for the fitting.

The one different main part for this venture is an GP1287 VFD (vacuum fluorescent show), which Pavleski selected for its excessive distinction and quick response time. It has a decision of 256×50 and that’s broad sufficient to point out two digital gauges side-by-side. The Nano merely performs an analog learn for every audio channel, then updates the graphical gauge utilizing the U8g2 library for monochrome shows. This VFD attracts numerous energy and that necessitates the usage of devoted energy provide. The one different parts vital are resistors, capacitors, and a rotary potentiometer.