Aosong
AHT20
±0.3 °C · ±2 %RH · I²C · 2 to 5.5 V
A small, low-cost I²C sensor with ±0.3 °C and ±2 %RH: the usual upgrade from a DHT22.
Watch out: Fixed address 0x38, so one per bus. In ESPHome, use the aht10 component with variant AHT20.
AHT20 vs DHT22
7 of the 10 features in our table differ between the AHT20 and the DHT22.
Aosong
DHT22
±0.5 °C · ±2 %RH · Single wire (own protocol) · 3.3 to 6 V
A step up from the DHT11: ±0.5 °C, ±2 %RH typical and down to −40 °C, still on one data wire.
Watch out: The humidity error can reach ±5 %RH, one reading every 2 s at most, and its own protocol needs precise timing. About 50 µA between readings.
Differences
| Feature | AHT20 | DHT22 |
|---|---|---|
| Temperature accuracy | ±0.3 °C | ±0.5 °C |
| Temperature range | −40 to 85 °C | −40 to 80 °C |
| Interface | I²C | Single wire (own protocol) |
| I²C address | 0x38 | Not I²C |
| Supply | 2 to 5.5 V | 3.3 to 6 V |
| Current between readings | 0.25 µA | 50 µA |
| ESPHome | aht10 | dht |
Same on both: measures · humidity accuracy · status.
Choose the AHT20 if you need
- better temperature accuracy (±0.3 °C against ±0.5 °C)
- a standard I²C bus shared with other sensors
- less current between readings (0.25 µA against 50 µA)
Choose the DHT22 if you need
- a ready-made configuration in this site’s ESPHome generator
Open the sensor comparison →Tick what your project needs and see which sensor fits best.
AHT20: I²C address, wiring and pull-ups →
Frequently asked questions
What is the difference between the AHT20 and the DHT22?
The AHT20 offers better temperature accuracy, a standard I²C bus shared with other sensors, and less current between readings. The DHT22 offers a ready-made configuration in this site’s ESPHome generator.
Which is more accurate, the AHT20 or the DHT22?
Typical datasheet figures: temperature ±0.3 °C for the AHT20 and ±0.5 °C for the DHT22; humidity ±2 %RH and ±2 %RH. Placement matters as much as accuracy: keep either away from the board’s warm parts.
Can I replace the AHT20 with the DHT22?
Not as a drop-in: the AHT20 uses I²C and the DHT22 a proprietary single-wire protocol, so the wiring and the code change.
Other comparisons
DHT22 vs BME280 DHT11 vs DHT22 DHT22 vs SHT31 AHT20 vs SHT31 DS18B20 vs DHT22
Figures from the makers’ datasheets and product pages and the ESPHome documentation, checked in November 2026.