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DHT22 climate logger

Read temperature and humidity every two seconds and print them as a log line.

Starter15 min115200 baud

Board

ESP32

3V3

GND

CMD

CLK

Fig. 1. Pins this project uses on the ESP32-DevKitC V4, 38 pin. USB connector at the bottom.

Wiring

From	To board	Note
DHT22 VCC	3V3
DHT22 DATA	GPIO 4	10 kΩ pull-up to 3V3 on a bare sensor
DHT22 GND	GND

Tested on this board

Not run on this board yet. Treat the wiring and code as a first draft.

Firmware, Arduino sketch for ESP32 Dev Module

#include <DHT.h>

DHT dht(4, DHT22);

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

void loop() {
  delay(2000);
  float h = dht.readHumidity();
  float t = dht.readTemperature();
  if (isnan(h) || isnan(t)) {
    Serial.println("Sensor read failed, check wiring");
    return;
  }
  Serial.printf("%.1f C  %.1f %%RH\n", t, h);
}

3V3

GND

3V3

RST

GND

Fig. 1. Pins this project uses on the ESP32-S3-DevKitC-1, 44 pin. USB connector at the bottom.

Wiring

From	To board	Note
DHT22 VCC	3V3
DHT22 DATA	GPIO 4	10 kΩ pull-up to 3V3 on a bare sensor
DHT22 GND	GND

Tested on this board

Not run on this board yet. Treat the wiring and code as a first draft.

Firmware, Arduino sketch for ESP32S3 Dev Module

#include <DHT.h>

DHT dht(4, DHT22);

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

void loop() {
  delay(2000);
  float h = dht.readHumidity();
  float t = dht.readTemperature();
  if (isnan(h) || isnan(t)) {
    Serial.println("Sensor read failed, check wiring");
    return;
  }
  Serial.printf("%.1f C  %.1f %%RH\n", t, h);
}

GND

3V3

GND

RST

GND

Fig. 1. Pins this project uses on the ESP32-C3-DevKitM-1, 30 pin. USB connector at the bottom.

Wiring

From	To board	Note
DHT22 VCC	3V3
DHT22 DATA	GPIO 4	10 kΩ pull-up to 3V3 on a bare sensor
DHT22 GND	GND

Tested on this board

Not run on this board yet. Treat the wiring and code as a first draft.

Firmware, Arduino sketch for ESP32C3 Dev Module

#include <DHT.h>

DHT dht(4, DHT22);

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

void loop() {
  delay(2000);
  float h = dht.readHumidity();
  float t = dht.readTemperature();
  if (isnan(h) || isnan(t)) {
    Serial.println("Sensor read failed, check wiring");
    return;
  }
  Serial.printf("%.1f C  %.1f %%RH\n", t, h);
}

Parts

Quantity	Part	Where to buy
1×	ESP32 dev board	Buy at Amazon
1×	DHT22 (AM2302) sensor
1×	10 kΩ resistor, only for a bare sensor without a breakout
3×	Jumper wires

Amazon buy links may include an Associates tag, and this site may earn a commission from qualifying Amazon purchases at no extra cost to you. Adafruit links are direct.

Libraries

DHT sensor library (Adafruit), Adafruit Unified Sensor

Load it

In the Arduino IDE, install the esp32 board package and pick the board named above the sketch.
Install the libraries listed above from the Library Manager.
Paste the sketch, choose the board's port and upload. Hold BOOT if the upload stalls at Connecting.
Close the IDE's serial monitor, then open the bench here to watch the output.

Open the bench at 115200 baud