Thank you all for your invaluable solutions and clarifications on my issue. Your help is greatly appreciated!

neither SHT30 nor SHT40 allow for an I2C address change programmatically. The I2C address of SHT30 can be changed via ADDR pin; SHT40 is sold in two variants with two I2C addresses. Please also see my post here.

Thanks
Felix

https://shop.m5stack.com/products/i2c-hub-1-to-6-expansion-unit-pca9548apw

They are easy to set up and work very well.

Thanks
Surya

Here I am encountering another challenge: I'm attempting to read temperature data from both the SHT30 and SHT40 simultaneously. However, both sensors share the same I2C address (0x44), leading to an error. I also experimented with changing the address to 0x45, but unfortunately, it didn't resolve the issue. Any advice is greatly appreciated.

Here is my new setup:

Code:

#include <M5AtomS3.h>
#include <M5Unified.h>
#include "Wire.h"
#include "M5UnitENV.h"
#include <SensirionI2CSht4x.h>

SHT3X sht3x;
SensirionI2CSht4x sht4x;

float temperature, humidity;

void setup()
{
  Serial.begin(115200);

  if (!sht3x.begin(&Wire, SHT3X_I2C_ADDR, 2, 1, 400000U))
  {
    Serial.println("Couldn't find SHT3X");
    // while (1)
    // {
    //   Serial.println("Couldn't find SHT3X");
    //   delay(1000);
    // }
  }
  sht4x.begin(Wire, SHT40_I2C_ADDR_45);
}

void loop()
{
  temperature = humidity = NULL;
  uint16_t error;
  char errorMessage[256];
  if (sht3x.update())
  {
    Serial.println("-----SHT3X-----");
    Serial.print("Temperature: ");
    Serial.print(sht3x.cTemp);
    Serial.println(" degrees C");
    Serial.print("Humidity: ");
    Serial.print(sht3x.humidity);
    Serial.println("% rH");
    Serial.println("-------------\r\n");
  }

  error = sht4x.measureHighPrecision(temperature, humidity);
  if (error)
  {
    Serial.print("Error trying to execute measureHighPrecision(): ");
    errorToString(error, errorMessage, 256);
    Serial.println(errorMessage);
  }
  else
  {
    Serial.println("-----SHT4X-----");
    Serial.print("Temperature:");
    Serial.print(temperature);
    Serial.print("\t");
    Serial.print("Humidity:");
    Serial.println(humidity);
    Serial.println("-------------\r\n");
  }
  delay(1000);
}

Thanks
Surya

#include "M5UnitENV.h"
SHT3X sht3x;

void setup() {           //runs once on start up
  Serial.begin(115200);  //open the serial port for USB cable
  delay(500);
  Serial.println("in setup");
  delay(1000);  //wait for a second
}

void loop() {  
  if (sht3x.begin(&Wire, 0x44, 2, 1, 400000U)) {
     Serial.println("Address 44 detected");
  } else if (sht3x.begin(&Wire, 0x45, 2, 1, 400000U)) {
    Serial.println("Address 45 detected");
  } else {
    Serial.println("No ENV detected");
  }

-Terry

maybe checkout this example here. It uses an SHT30 as well.

Thanks
Felix