DHT22 AM2302 Sensor | Digital Temperature Humidity Probe

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DHT22 AM2302 Temperature and Air Humidity Sensor - Digital Probe for Climate and Weather Monitoring The DHT22 AM2302 temperature and air humidity sensor is a low-cost digital envir onmental sensor for microcontroller projects that need reliable indoor climate readings. It combines a capacitive humidity element and temperature measurement circuit, then outputs calibrated data over a single digital signal line so the host system does not need analog inputs. This product is well suited for smart-home nodes, greenhouse monitoring, weather stations, HVAC experiments, and learning projects. It can be wired to Arduino-compatible boards like the ELAB Nano V3, Pico-class hosts like the Raspberry Pi Pico W, or quick prototypes using an MB 102 Breadboard Kit. If a project needs pressure and gas trend sensing as well, the BME680 Sensor Board is a useful upgrade path. The DHT22/AM2302 works with 3.3V and 5V controller ecosystems and is intended for slow environmental readings with a typical two-second sampling interval. For best results, place it where air can circulate and keep it away from direct heat sources, water droplets, and enclosed hot electronics. Technical Specifications Parameter Value SKU TB-DHT22-Sensor Model DHT22 / AM2302 Sensor Element Capacitive humidity sensor and temperature measurement element Output Signal Digital single-bus signal Supply Voltage 3.3V-6V DC Humidity Range 0-100% RH Temperature Range -40C to +80C Humidity Accuracy Approx. +/-2% to +/-5% RH depending on conditions Temperature Accuracy Approx. +/-0.5C Resolution 0.1C and 0.1% RH Detection Period 2 seconds Signal Pins VCC, DATA, GND depending on package/module format Typical Applications Weather stations, air humidity monitoring, greenhouse logging, room comfort sensing Board Layout & Label Guide VCC - Connect to a compatible 3.3V or 5V supply. DATA - Single digital data output line to the host GPIO. GND - Common ground. Sensor Body - Expose to ambient air for accurate humidity readings. Pull-Up - DATA commonly requires a pull-up resistor unless the module includes one. Sampling Timing - Use at least a two-second interval between reads. Placement - Avoid nearby heat sources and direct water contact. Cable Length - For longer wires, reduce noise with stable power, good ground, and suitable pull-up value. Application Scenarios 1. Arduino DHT22 Monitor Print temperature and humidity through the serial monitor. #include DHT dht(2, DHT22); void setup() { Serial.begin(115200); dht.begin(); } void loop() { Serial.print("T="); Serial.print(dht.readTemperature()); Serial.print("C H="); Serial.println(dht.readHumidity()); delay(2000); } 2. Greenhouse Humidity Alarm Turn on an alarm output when humidity drops below a target level. #include DHT dht(2, DHT22); const int alarmPin = 8; void setup() { pinMode(alarmPin, OUTPUT); dht.begin(); } void loop() { float humidity = dht.readHumidity(); digitalWrite(alarmPin, humidity < 45.0 ? HIGH : LOW); delay(2000); } 3. MicroPython Room Monitor Read DHT22 values from an ESP32 running MicroPython. import dht from machine import Pin import time sensor = dht.DHT22(Pin(15)) while True: sensor.measure() print("C:", sensor.temperature(), "RH:", sensor.humidity()) time.sleep(2) 4. Python CSV Logger Write repeated readings to a CSV file for trend review. import time import board import adafruit_dht sensor = adafruit_dht.DHT22(board.D4) with open("climate.csv", "a", encoding="utf-8") as f: while True: try: f.write(f"{time.time():.0f},{sensor.temperature},{sensor.humidity}\n") f.flush() except RuntimeError: pass time.sleep(2) Packing List 1 x DHT22 AM2302 Temperature and Air Humidity Sensor FAQ Q: Is this the same sensor family as AM2302?A: Yes. DHT22 and AM2302 are commonly used names for this digital temperature and humidity sensor family. Q: Does it need an analog pin?A: No. It uses a digital single-bus output. Q: What voltage can I use?A: The current listing specifies 3.3V to 6V DC. Q: How fast can it update?A: Use a two-second reading interval. Q: Can I use it for outdoor weather?A: Yes for protected weather-station experiments, but shield it from rain and direct sun. Q: Why do I get NaN or failed reads?A: Check timing, wiring, pull-up resistor, library selection, and cable length. Q: Is it calibrated?A: It outputs calibrated digital readings suitable for hobby and education use. Q: Can it measure soil moisture?A: No. It measures air humidity, not soil moisture. Show more