AHT20 Temperature & Humidity Sensor
Low-cost temperature and humidity sensor. Good for basic environmental monitoring where ±2% accuracy is sufficient.
Say it to PAL
“What is the temperature and humidity in here?”
The code PAL writes
const temp = await p.read('qwiic-aht20', 'temperature');
const hum = await p.read('qwiic-aht20', 'humidity');
p.log(`Temp: ${temp}°C, Humidity: ${hum}%`);“Tell me when the air gets too humid.”
The code PAL writes
p.onSensorChange('qwiic-aht20', 'humidity', (rh) => {
if (rh > 70) p.notify('High humidity: ' + rh + '%');
});
await p.waitUntilStopped();When to pick it
Use as a budget option when basic temperature and humidity is enough. At ~$4.50 it is the cheapest temp/humidity option. For better accuracy or additional pressure, use BME280 instead.
Good to know
- Measurement cycle takes ~80ms. Reading faster than once per 2 seconds degrades accuracy.
- No pressure measurement — use BME280 if you also need barometric data.
About it
The Aosong AHT20 is an affordable temperature and humidity sensor using capacitive humidity sensing and a thermistor. It provides ±0.3°C temperature accuracy and ±2% RH humidity accuracy. While not as precise as SHT40 or BME280, it is an excellent budget choice for simple projects needing basic environmental data. The fixed I2C address (0x38) means only one can be used per bus without a mux.
Where to buy
Facts
Tested
It is in our catalog, but nobody has checked it on a real board. It may not work yet. Its driver is written, but it has not been tested on hardware yet.
I2C address
The AHT20 Temperature & Humidity Sensor answers at I2C address 0x38. The address is fixed.
Current
250 µA
The catalog lists a typical draw of 250 µA for the Temp & Humidity, copied from the maker’s description and not measured by Palpable.
Board size
25.4 × 17.78 mm
The Temp & Humidity board measures 25.4 × 17.78 mm and stands 4.6 mm tall with its parts. It has 4 mounting holes. These dimensions are from the maker’s mechanical drawing.
Free to reuse
Every fact here is open data under CC BY 4.0. Copy it into your own docs or code, and credit Palpable. Download it
This record was last changed on October 26, 2026.