AHT20 temperature + humidity with ESP32

Supply 3.3-5 V Bus I2C I2C address 0x38 Measures temperature, humidity

Pins and ESP32 wiring

Pin	Role	ESP32 pin
VIN	Power	3V3
GND	Ground	GND
SCL	I2C clock (SCL)	D22
SDA	I2C data (SDA)	D21

Suggested wiring for the 30-pin ESP32 DevKit, avoiding flash, input-only and strapping pins. BoardPilot checks it for you as you wire.

Good to know

Its address is fixed at 0x38: one per bus. The DHT20 uses the same chip and the same address. (Aosong AHT20 datasheet, Sensor address 0x38)
After power-up, wait 40 ms; each measurement takes about 80 ms. (Aosong AHT20 datasheet, Sensor reading process)

Starter code (Arduino)

#include <Wire.h>

void setup() {
  Serial.begin(115200);
  Wire.begin(21, 22);  // SDA = GPIO 21, SCL = GPIO 22
  Wire.beginTransmission(0x38);
  bool found = Wire.endTransmission() == 0;
  Serial.println(found ? "AHT20 temperature + humidity found at 0x38" : "Not found: check power, GND and SDA/SCL");
}

void loop() {}