DHT22

Connects over

GPIO pins

Made by

Aosong

Datasheet

cdn-shop.adafruit.com

Use it

hardware {
    device dht22: DHT22(pin: 16)
}

every 1s {
    let value: float = dht22.temperature()
    log("dht22", "temperature={value}")
}

The DHT22 is wired to ordinary GPIOs: give each of its pins (pin) as a named argument. The compiler checks every pin can do its job.

Methods

• dht22.temperature() -> float

  Temperature in °C

• dht22.humidity() -> float

  Humidity %

Wiring

Specifications

Voltage

3.3V – 6V

Current

1.5 mA measuring, 50 μA standby

Temp

−40°C to +80°C ±0.5°C

Humidity

0 – 100% RH ±2 – 5%

Sample rate

Every 2 s (slower than DHT11)

Tips

• Marketed as AM2302 — same chip.
• Single-wire protocol is timing-critical — many MCU libraries disable interrupts during read.
• If you query faster than every 2 s you get the previous reading.

Alternatives worth knowing:

• AHT20: I²C, cheaper, similar accuracy. Strongly recommended for new designs.
• SHT31: Sensirion — top-tier accuracy and reliability.
• BME280: Adds pressure if you need altitude / weather.