ESP32 Temperature Monitor

A complete sensor project using 3.3 V logic, a local wiring diagram, working serial code, measured results and practical invalid-reading checks.

1. 1Connect DHT11 VCC to 3V3, DATA to GPIO 4 and GND to GND.
2. 2Install the matching DHT sensor library and select the ESP32 board.
3. 3Upload the sketch and open Serial Monitor at 115200 baud.
4. 4Record three readings at least two seconds apart.

#include <DHT.h>

#define DHTPIN 4
#define DHTTYPE DHT11
DHT dht(DHTPIN, DHTTYPE);

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

void loop() {
  float temperature = dht.readTemperature();
  float humidity = dht.readHumidity();
  Serial.printf("T: %.1f C  H: %.1f %%\n", temperature, humidity);
  delay(2000);
}

• If values are invalid, wait two seconds and recheck the sensor type.
• If upload fails, hold BOOT only when required by the board variant.
• If readings jump, shorten signal wires and verify the pull-up connection.