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DHT22 AM2302 Sensor | Digital Temperature Humidity Probe
DHT22 AM2302 Sensor | Digital Temperature Humidity Probe
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 environmental 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.h>
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.h>
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.
1. General Shipping Information
- We provide premium shipping methods with a tracking number for each order.
- Shipping addresses must be entered in English without special symbols to help the courier company recognize your address in the system. We will ship strictly according to the shipping address you provided. Please notify us of any address change before your order is marked "Shipped" to avoid parcel loss.
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- We can ship all in-stock orders within 1 business day after your order has been confirmed.
- All items are inspected before dispatch and are carefully hand-packed.
- With standard courier practice, you need to check the contents of the parcel before signing for your goods. Otherwise, we will not be held responsible for any damage that may have occurred in transit.
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2. Shipping Rates & Options
Our shipping rates are calculated based on the order value and destination. Please refer to the tables below for details.
2.1 Germany (Domestic)
| Shipping Method | Order Value | Cost | Est. Delivery |
|---|---|---|---|
| Deutsche Post | €0 - €50.00 | €4.95 | 2-4 Business Days |
| Deutsche Post | Over €50.00 | Free | 2-4 Business Days |
|
DHL Paket (Faster Delivery) |
€0 - €50.00 | €6.95 | 1-3 Business Days |
|
DHL Paket (Faster Delivery) |
€50.00 - €100.00 | €2.00 | 1-3 Business Days |
|
DHL Paket (Faster Delivery) |
Over €100.00 | Free | 1-3 Business Days |
2.2 European Union (EU)*
*Including:
| Shipping Method | Order Value | Cost | Est. Delivery |
|---|---|---|---|
| Deutsche Post | €0 - €100.00 | €7.95 | 5-9 Business Days |
| Deutsche Post | Over €100.00 | Free | 5-9 Business Days |
|
DHL Paket (Faster Delivery) |
€0 - €100.00 | €15.95 | 3-7 Business Days |
|
DHL Paket (Faster Delivery) |
€100.00 - €250.00 | €7.95 | 3-7 Business Days |
|
DHL Paket (Faster Delivery) |
Over €250.00 | Free | 3-7 Business Days |
2.3 United States
| Region | Shipping Method | Order Value | Cost | Est. Delivery |
|---|---|---|---|---|
|
Continental U.S. (50 States) |
USPS Ground Advantage | €0 - €45.00 | €5.95 | 3-7 Business Days |
| USPS Ground Advantage | Over €45.00 | Free | 3-7 Business Days | |
| USPS Priority Mail | €0 - €45.00 | €16.95 | 1-4 Business Days | |
| USPS Priority Mail | Over €45.00 | €14.95 | 1-4 Business Days | |
|
Non-Continental U.S. (AK, HI, PR, etc.) |
USPS Ground Advantage | €0 - €60.00 | €6.95 | 5-9 Business Days |
| USPS Ground Advantage | Over €60.00 | Free | 5-9 Business Days |
* The regions in the Non-Continental U.S. include: Alaska, American Samoa, Guam, Hawaii, the Marshall Islands, the Northern Mariana Islands, Palau, Puerto Rico, the U.S. Virgin Islands, and all U.S. Armed Forces addresses. The shipping and delivery to these areas are subject to the Non-Continental U.S. shipping rules.
2.4 International (Outside EU)
For specific international destinations, including Switzerland, United Kingdom, and Norway.
| Order Amount | Shipping Cost |
|---|---|
| €0 - €300.00 | €19.95 |
| Over €300.00 | Free |
Important Notice:
- Inventory Status: Please check the inventory status on the product page. Our system displays real-time stock for our Munich and Arlington warehouses. If an item is out of stock in these locations, it will be marked as "Pre-order". You can still place an order for these items.
- Pre-order Fulfillment: For "Pre-order" items, we arrange the most efficient logistics solution to ensure you receive your goods as quickly as possible. Your package may be shipped directly from our Shenzhen warehouse. Alternatively, as part of our standard restocking process, we may transport the goods to our Munich or Arlington warehouse first (typically taking 5-10 business days) before dispatching them to you.
- Split Shipments: If your order contains both in-stock and Pre-order items, we will prioritize shipping the in-stock items from the local warehouse immediately. The remaining Pre-order items will be sent to you in a separate shipment once they are ready.
3. International Warehouse
Our products are stored in our Munich, Arlington, and Shenzhen warehouses to provide more flexible logistics solutions tailored to different regions and customer needs. On each product's description page, we indicate the specific warehouse location to help you better plan your purchase and delivery schedule.
3.1 German Warehouse
For products stored in our warehouse in Munich, we use either Deutsche Post or DHL for shipping, depending on the size of the package. Logistics within Germany are very efficient, with an estimated delivery time of 2-4 business days, ensuring you receive your order quickly and conveniently. For Western EU countries, the estimated delivery time is 4-6 business days. For Eastern EU countries, the estimated delivery time is 6-8 business days.
3.2 US Warehouse
For products stored in our warehouse in Arlington, we use either USPS or UPS for shipping, depending on the size of the package. Logistics within U.S. are very efficient, with an estimated delivery time of 3-7 business days, ensuring you receive your order quickly and conveniently.
3.3 Chinese Warehouse
For Pre-order items or orders fulfilled directly from our Shenzhen warehouse, we utilize YunExpress for reliable international shipping. Given the complexities of international shipping, the estimated delivery time for these packages is around 10 business days, though this may vary slightly due to customs processes or other uncontrollable factors. Otherwise, products will be restocked to our Munich or US warehouses before final delivery, as detailed in the "Important Notice" above.
4. Customs and Taxes
4.1 How are customs handled by OpenELAB for import or export?
For EU Member States: Whether shipped from Germany or China, we cover all import duties and taxes (DDP), ensuring that you receive your package without any additional costs or hassle with customs.
For countries outside of the European Union, such as Switzerland and Norway, you may be subject to import duties, taxes, and/or customs fees charged upon delivery. These fees vary from country to country and are the sole responsibility of the recipient.
⚠️ Refusal of Delivery: If you refuse to pay these fees upon delivery and the package is returned to us, the refund amount will be calculated after deducting the original shipping costs, return shipping costs, and any applicable customs or storage fees.
4.2 How is VAT charged when the Customer places an order from OpenELAB?
In accordance with the newest VAT e-commerce rules in the EU, OpenELAB shall have the right to charge the amount of VAT at checkout. The standard rate of actual VAT applied is subject to the destination country's regulations. No additional VAT will be charged upon delivery for these orders.
