ESP32-S3 ADC Read Issue

[APE_ESP]

am trying to test the ADC function in the ESP32-S3. Below is my test code. I am using GPIO4. When I try to run 0V into GPIO4, I am read a value of approximately zero for a while and then I read a raw value of approximately 400 for a while and then back to zero and this behavior repeats. Does any one have any idea have any idea what is going on here? Here is the serial output:
3
3
3
3
0
391
373
412
415
409
411
416
407
416
405
408
402
409
391
413
432
412
5
3
7
9
4
5
2
3
0
7
5
3
5
9
5
3
9
4
404
414
425
397
384

ARDUINO CODE:

Code: Select all

#include <esp_adc_cal.h>
#include <esp32-hal-adc.h>

void setup() {
  // initialize serial communication at 115200 bits per second:
  Serial.begin(115200);

  analogReadResolution(12);
  pinMode(4, INPUT);  //GPIO4
  adcAttachPin(4);    //GPIO4
}


void loop() {

  int RawADC= adc1_get_raw(ADC1_CHANNEL_3); //GPIO4

  Serial.println(RawADC,0); // Print Raw ADC Value 

  delay(200);  // delay in between reads for clear read from serial
}

[bidrohini]

I think, here you may get your answer: viewtopic.php?t=27297