DHT11 temperature and humidity sensor: specs and pinout
Low-cost digital temperature and humidity sensor with a single-wire data output.
Specs
| Spec | Value | Source |
|---|---|---|
| Supply voltage | 3.3 V to 5.5 V DC | source Electrical characteristics, Table 2 |
| Supply current | 0.06 mA (standby) to 1.0 mA (measurement) | source Electrical characteristics, Table 2 |
| Humidity precision | ±5 %RH; precision range 5 to 95 %RH | source Table 1, relative humidity performance |
| Temperature precision | ±2 °C at 25 °C | source Table 2, temperature performance |
| Sampling period | More than 2 s per reading | source Table 2, electrical characteristics |
| Data-line pull-up | About 4.7 kΩ | source Single-bus signal section |
Power
| Value | Source | |
|---|---|---|
| Supply | 3.3 V to 5.5 V DC | source Electrical characteristics, Table 2 |
| Current | 0.06 mA (standby) to 1.0 mA (measurement) | source Electrical characteristics, Table 2 |
Chip pins
These are the pins of the chip on the module, from the chip datasheet. The module's own header may label or expose them differently. Module header labels (VCC, GND, SDA, SCL…) come from the Compoden listing, not an official module schematic.
| Pin | Function | Voltage | Notes | Source |
|---|---|---|---|---|
| VDD (pin 1) | Power supply | 3.3 V to 5.5 V DC | source Pin description (section 4) | |
| DATA (pin 2) | Serial data, single bus | Datasheet example uses a 4.7 k pull-up on the data line for cable lengths under 5 m; the data-line voltage limits are not stated | source Pin description (section 4) | |
| NC (pin 3) | Empty pin (not connected) | source Pin description (section 4) | ||
| GND (pin 4) | Ground, power supply negative | source Pin description (section 4) |
Common mistakes
- Reading the sensor more often than every 2 seconds: the sampling period is more than 2 s (source)
- Leaving out the data-line pull-up: the datasheet uses about 4.7 kΩ to hold the bus high (source)
- Using a long supply cable at 3.3 V: the datasheet says to keep the cable as short as possible (source)
What we could not confirm
- Humidity and temperature scale ranges: the datasheet copy's table cells are blank or unclear, and its revision-history text gives conflicting values. Not stated. The listing's 20 to 80 %RH and 0 to 50 °C are not used.
- The datasheet copy is a 2017 retailer copy. Confirm the values against the Aosong original.
- Module-level pull-up values and wiring are not in the datasheet.
- Pin rows are the 4-pin DHT11 sensor body (Aosong datasheet, retailer copy dated 2018-01-19). The listing's module header has 3 pins (VCC, GND, DATA) and omits NC; whether the module has a pull-up resistor is not from an official source.
Sources
- Aosong DHT11 datasheet V1.3, 2017-03-31 (official site: link).
- Copy of the Aosong DHT11 datasheet hosted by Akizuki, a retailer: akizukidenshi.com/goodsaffix/DHT11_20180119.pdf.
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