Type Definition dht_hal::Dht11

type Dht11<P, T> = Dht<P, T, Dht11>;

A DHT11 sensor.

These things are literally everywhere — you've definitely seen one and probably own several.

A DHT11 is a small, blue rectangle 15.5mm x 12mm on its face and 5.5mm wide. The DHT11 has a 1Hz sampling rate, meaning it can be read up to once every second. It supposedly works with 3.3V to 5V power and IO voltage — sometimes they have been known to not work when supplied 3.3v. It needs a 10 KOhm pullup resistor across the VCC and DATA pins, which most sellers will stick in the bag with it.

The DHT11 works between 20-80% relative humidity with 5% accuracy, and 0-50C with +- 2C accuracy. Which is to say...it's not a very good sensor. The primary advantage is that it is dirt cheap and about as common, which is why they can be found in every beginner's electronics kit.