Unexpected interrupt on GPIO39 (SENSOR_VN) when reading ADC on GPIO 27

[tcfx44]

I'm using ESP32-WROOM-32E with platformio, platform = espressif32, current espressif 32 platform version is 6.12.0.

I'm receiving an interrupt on gpio 39 every time I read the ADC on gpio 27. I do have an external pullup to 3.3v on gpio 39 pin.

What migh be the reason for this behaviour and is there any workaround. My code is as follows:

Code: Select all

#include <Arduino.h>

void gpio39_isr() {
  Serial.println("ISR 39");
}

void gpio26_isr() {
  Serial.println("ISR 26");
}

void setup(void) {
  Serial.begin(115200);

  pinMode(39, INPUT_PULLUP);
  attachInterrupt(39, gpio39_isr, FALLING);

  pinMode(26, INPUT_PULLUP);
  attachInterrupt(26, gpio26_isr, FALLING);

}

void loop(void) {
  Serial.print("ADC raw value on pin 27: ");
  Serial.println(analogRead(27));
  delay(200);
}