AHT20 / AHT30
Also known as: AHT20 · AHT21 · AHT30 · ASAIR AHT20 · Temperature & humidity
Under a dollar for genuinely usable temperature and humidity. The default 'sprinkle climate sensing everywhere' part, and the T/H half of the ubiquitous ENS160+AHT21 combo board.
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At a glance
⚑ flag an error| Measures | temperature, humidity |
|---|---|
| Accuracy | ±0.3 °C / ±2 %RH — the cheapest respectable T/H |
| Interface | I2C @ 0x38 |
| Supply | 2.2–5.5 V (module) |
| Battery-viable | Yes (deep-sleep friendly) |
| ESPHome | Native ESPHome component — aht10 |
| Typical price | $1-2 (street, varies) |
Compare all sensor modules in one table →
Which one do I buy?
vs SHT4x: the SHT is more accurate and better documented for ~$1 more. The AHT wins purely on price-per-room.
Clone check
Good for
Gotchas to know
- Uses the aht10 ESPHome component (covers AHT10/20; AHT30 generally works — verify your batch).
- Single fixed I2C address (0x38) — one per bus without a multiplexer.
Wiring it up
It's I2C, so it shares two pins with every other I2C sensor you own — chain your climate/light/CO2 stack on one bus and mind the address clashes (this one lives at 0x38). Any ESP32 dev board works.