HTU31 Humidity and Temperature Sensor and ESP32 board example

Product Type Features

Humidity Sensor Component Product Type  RHT
Humidity Sensor Component Sensor Type  Digital

Electrical Characteristics

Supply Voltage (Peak) (V) – 6v maximum
Current Consumption (mA) .76, .77, .78

Usage Conditions

Humidity Operating Range (%RH) – Humidity measurement range is 0 to 100% relative humidity
Operating Temperature Range (°C) – Temperature measurement range is -40 -degrees C to +125-degrees C
Operating Temperature Range (°F) -40 – 257, -40 – 258, -40 – 259

Parts Required

The sensor you can pick up in the $3 price range – you can connect to the sensor using a standard header the classic dupont style jumper wire.

Name	Link
ESP32		Aliexpress link Amazon Ebay
HTU31D		Aliexpress link Ebay link Amazon Link
Connecting cables		Aliexpress link Amazon Ebay

Schematic/Connection

Code Example

This uses a library from Adafruit installed using the Library Manager in the Arduino IDE. search for HTU31, and select the Adafruit_HTU31D library. You will also need to add another couple of libraries Adafruit BusIO library and the Adafruit Unified Sensor library

[codesyntax lang=”cpp”]

#include <Wire.h>
#include "Adafruit_HTU31D.h"

Adafruit_HTU31D htu = Adafruit_HTU31D();
uint32_t timestamp;
bool heaterEnabled = false;

void setup() {
  Serial.begin(115200);
  while (!Serial) {
    delay(10); // wait till serial port opens
  }
  Serial.println("Adafruit HTU31D test");

  if (!htu.begin(0x40)) {
    Serial.println("Couldn't find sensor!");
    while (1);
  }
  timestamp = millis();
}

void loop() {
  sensors_event_t humidity, temp;
  
  htu.getEvent(&humidity, &temp);// populate temp and humidity objects with fresh data

  Serial.print("Temp: "); 
  Serial.print(temp.temperature);
  Serial.println(" C");
  
  Serial.print("Humidity: ");
  Serial.print(humidity.relative_humidity);
  Serial.println(" \% RH");

  // every 5 seconds
  if ((millis() - timestamp) > 5000) {
    // toggle the heater
    heaterEnabled = !heaterEnabled;
    if (heaterEnabled) {
      Serial.println("Turning on heater");
    } else {
      Serial.println("Turning off heater");
    }
    if (! htu.enableHeater(heaterEnabled)) {
      Serial.println("Command failed");
    }

    timestamp = millis();
  }

  delay(500);
}

[/codesyntax]

Output

Here is  an example of what I saw in the serial monitor window

Links