AHT20 Temperature & Humidity Sensor and ESP8266 example using the Arduino IDE

In this article we look at a AHT20 Temperature & Humidity Sensor and we will connect it to a Wemos Mini

First lets look at the sensor

AHT20, as a new generation of temperature and humidity sensors, has established a new standard in size and intelligence. It is embedded in a double row flat no-lead package suitable for reflow soldering, with a bottom of 3 x 3 mm and a height of 1.0 mm.

The sensor outputs calibrated digital signals in standard IAHT20, as a new generation of temperature and humidity sensors, has established a new standard in size and intelligence.

It is embedded in a double row flat no-lead package suitable for reflow soldering, with a bottom of 3 x 3 mm and a height of 1.0 mm.

The sensor outputs calibrated digital signals in standard I²C format. AHT20 is equipped with a newly designed ASIC chip, an improved MEMS semiconductor capacitive humidity sensing element and a standard on-chip temperature sensing element.

Parts List

Here are the parts I used

Schematic/Connection

I used the Adafruit AHT20 sensor and in this case used the Stemma connection on the sensor

For the STEMMA QT cables, it uses the Qwiic convention:

Black for GND
Red for V+
Blue for SDA
Yellow for SCL

So color coded for ease of use, this layout shows a connection to the module

Code Example

This uses the library from Adafruit installed using the Library Manager in the Arduino IDE. search for AHTx0 , and select the Adafruit AHTx0 Library library and also the Adafruit BusIO library

This is the default example

#include <Adafruit_AHTX0.h>

Adafruit_AHTX0 aht;

void setup() 
{
  Serial.begin(115200);
  Serial.println("Adafruit AHT10/AHT20 demo!");

  if (! aht.begin()) 
  {
    Serial.println("Could not find AHT? Check wiring");
    while (1) delay(10);
  }
  Serial.println("AHT10 or AHT20 found");
}

void loop() 
{
  sensors_event_t humidity, temp;
  aht.getEvent(&humidity, &temp);// populate temp and humidity objects with fresh data
  Serial.print("Temperature: "); 
  Serial.print(temp.temperature); 
  Serial.println(" degrees C");
  Serial.print("Humidity: "); 
  Serial.print(humidity.relative_humidity); 
  Serial.println("% rH");

  delay(500);
}

Output

Open the serial monitor and you should see something like this.

Temperature: 22.81 degrees C
Humidity: 52.19% rH
Temperature: 24.23 degrees C
Humidity: 53.64% rH
Temperature: 24.31 degrees C
Humidity: 52.84% rH
Temperature: 24.00 degrees C
Humidity: 51.91% rH

Links

Product download pdf