Weird Noise on ESP32-WROOM-32D

[ogutsu]

Hello everyone, the ESP32 that I ordered came up and I was testing it. I got weird results on ADC input. Whether pins are unconnected or connected to a sensor. I just got a periodic noise and no other data, no what sensor reads. It doesn't matter what I choose for input pin, or the cable that I feed the ESP32, result is the same. Just this graphs that got:

When the ESP32 is unconnected (results are between 0-150):

When I just put a jumper cable that unconnected on other end (results are between 0-4025:

The code:

#define INPUT_PIN 32

void setup() {
  Serial.begin(115200);
  pinMode(INPUT_PIN, INPUT);
}

void loop() {
  int lightValue = analogRead(INPUT_PIN);
  Serial.println(lightValue);
}

[jremington]

That behavior is typical of a floating input, which suggests that you either have a bad/intermittent connection, or failed to connect the grounds. Breadboards are unreliable, and check for poorly soldered or unsoldered connections.

Please post a close up, focused photo of your wiring.