Spark Logic

DHT11 humidity and temperature sensor pinout

The DHT11 measures relative humidity and temperature and sends a 40-bit frame over a single data wire.

Four-position sensor interface

4 contacts Current package

Aosong / ASAIR ·

Four-position sensor interface pinout

Four-position sensor interface
Front view with the vented face toward you and leads below. Pin 1 is at the left.
Selected pin details

1 · VDD

Supply input · Power

Device supply. Place the bypass capacitor close to this pin.

Aosong DHT11 Product Manual, pp. 3–5, mirrored by ManualsLib. This page uses that manual’s electrical revision.

Electrical limits · Link to this pin

All 4 pins

PinSignalDirectionFunction
1VDD Supply inputSupply input Device supply. Place the bypass capacitor close to this pin.
2DATA BidirectionalBidirectional Aosong single-wire pulse timing interface. The host pulls the line low to request data, then releases it.
3NC NoneNone No internal connection. Leave electrically open unless the package notes specify otherwise.
4GND Supply returnSupply return Connect to the common ground plane or bench return.

Signal assignments

Aosong single-wire bus

The sensor replies with two humidity bytes, two temperature bytes, and an additive checksum.

Electrical limits

ParameterLimitConditions and source
Supply3.5–5.5 V3.5–5.5 V The example uses a shared 5 V logic and supply rail. Aosong DHT11 Product Manual, pp. 3–5, mirrored by ManualsLib. This page uses that manual’s electrical revision.
Host start pulseAt least 18 ms lowAt least 18 ms low Release the line afterward and measure the sensor’s response. Aosong DHT11 Product Manual, pp. 3–5, mirrored by ManualsLib. This page uses that manual’s electrical revision.
Sample intervalMore than 2 sMore than 2 s Wait after power-up and leave time between requests. Aosong DHT11 Product Manual, pp. 3–5, mirrored by ManualsLib. This page uses that manual’s electrical revision.

Models and documents

The map applies to the four-pin bare DHT11 described in the linked manual. Three-pin breakout headers vary.

DHT11
Aosong four-pin sensor.