We probably don’t need to tell the average Hackaday reader that the ESP32 is a powerful and extremely flexible microcontroller. We’ve seen some incredible projects using this affordable chip over the last few years, and by the looks of it, the best is yet to come. That’s because it always takes some time before the community can really figure out how to get the most out of a piece of hardware.
Take for example the Bluetooth audio player that [squix] was recently working on. Getting the music going was no problem with the esp32-a2dp library, but when he wanted to add some visualizations the audio quality took a serious hit. Realizing that his Fast Fourier transform (FFT) code was eating up too much processor power, it seemed like a great time for him to explore using the ESP32’s second core.
[squix] had avoided poking around with the dual-core nature of the ESP32 in the past, believing that the second core was busy handling the WiFi communication. But by using the FreeRTOS queue system, he wrote some code that collects audio data with one core and runs the actual FFT magic on the other. By balancing the workload like this, he’s able to drive the array of 64 WS2812B LEDs on the front of the Icon64 seen in the video after the break.