Hardware:

Board: ESP32 Dev Module
Core Installation version: 1.0.5
IDE name: Arduino IDE
Flash Frequency: 40Mhz
PSRAM enabled: no
Upload Speed: 115200
Computer OS: Windows 10

Description:

I am developing an open source edrum module (source code at Github: https://github.com/corrados/edrumulus) on my ESP32 dev module (NodeMCU with dual core ESP32). For that I need to sample from multiple ADC at a rate of 8 kHz and do some digital signal processing. I have worked with version 1.0.4 and could successfully process up to 7 channels. After upgrading to version 1.0.5, now I cannot even process just one single channel. So, the same source code executes much slower now.

Basically, I am using a "hw_timer_t" and check with "hw_timer_t" to get a constant sampling rate. Then I am using analogRead(), the MIDI-library and some floating point calculations.