The idea
Owned and run by element14 Presents host Mark Donners, “The Digital Engineer” YouTube channel options a wide range of electronics initiatives that principally focus on spectrum analyzers. Taking inspiration from different subscriber depend shows, he needed to construct a model that featured a outstanding brand, digital counter, loads of RGB lighting, and naturally, a spectrum analyzer within the heart.
Circuit and PCB design
As a result of audio processing by itself will be fairly reminiscence and computationally intensive, Donners wanted a microcontroller that had sufficient energy to run the FFT algorithm. Moreover, this challenge would require loads of I/O for the microphone and LEDs, in addition to Wi-Fi connectivity for getting the newest subscriber depend, thus main him to choose the ESP32 DOIT improvement equipment. The circuit options an I2S microphone and amplifier for elevated audio constancy together with a potentiometer for quantity management. On the show facet, the PCB has headers for attaching a strip of WS2812B LEDs, a 6-digit, 7-segment module, and a MAX7219 dot-matrix panel. Lastly, energy is delivered by way of a 12V barrel plug, which is then regulated to a secure 5V supply for the LEDs and different parts.
Signal building
With the signal being such a big point-of-focus in his store, Donners made certain to create it with outstanding letters and a stand-out brand. The vast majority of the signal was minimize from a sheet of clear acrylic utilizing a laser earlier than the channel’s brand bought adhered to the highest. From right here, the 7-segment show module and panel of 8×8 LED matrices had been connected of their respective places whereas a field containing a number of rows of RGB LEDs was positioned behind the lettering. As soon as secured, the now-populated PCB was linked to each energy and every exterior module.
Firmware
The sketch answerable for working the signal begins by initializing an array of libraries, together with I2S audio, the dot-matrix array, Wi-Fi, and the RGB LED strip. Then in a loop, the microphone is continually polled for its newest readings, and as soon as the buffer has collected sufficient samples, the FFT algorithm is run to create the spectrum analyzer. Each 5 seconds, the ESP32 will get the newest subscriber depend from the YouTube API, and if a brand new subscriber has been added, a sound will play from the connected speaker.
To see the show in motion or learn the way Donners constructed such an interactive, linked signal, you may watch his video right here on the element14 Presents YouTube Channel.