sensirion / arduino-i2c-sht4x

Arduino library for Sensirion SHT4x sensors

Sensirion I²C SHT4X Arduino Library

This is the Sensirion SHT4X library for Arduino allowing you to communicate with a sensor of the SHT4X family over I²C.

Click here to learn more about the Sensirion SHT4X sensor family.

Supported sensor types

Sensor name	I²C Addresses
SHT40	0x44, 0x45
SHT41	0x44, 0x45
SHT45	0x44, 0x45

The following instructions and examples use a SHT40.

Installation of the library

This library can be installed using the Arduino Library manager: Start the Arduino IDE and open the Library Manager via

Sketch ➔ Include Library ➔ Manage Libraries...

Search for the Sensirion I2C SHT4X library in the Filter your search... field and install it by clicking the install button.

If you cannot find it in the library manager, download the latest release as .zip file and add it to your Arduino IDE via

Sketch ➔ Include Library ➔ Add .ZIP Library...

Don't forget to install the dependencies listed below the same way via library manager or Add .ZIP Library

Dependencies

• Sensirion Core

Sensor wiring

Use the following pin description to connect your SHT4X to the standard I²C bus of your Arduino board:

Pin	Cable Color	Name	Description	Comments
1	green	SDA	I2C: Serial data input / output
2	black	GND	Ground
3	yellow	SCL	I2C: Serial clock input
4	red	VDD	Supply Voltage	1.1V to 3.6V

The recommended voltage is 3.3V.

Please refer to the datasheet for proper circuit setup. There are 3rd party boards for easy connection of the SHT4x sensor to your Arduino Board.

Board specific wiring

You will find pinout schematics for recommended board models below:

Arduino Uno

SHT4X	SHT4X Pin	Cable Color	Board Pin
SDA	1	green	D18/SDA
GND	2	black	GND
SCL	3	yellow	D19/SCL
VDD	4	red	3.3V

Arduino Nano

SHT4X	SHT4X Pin	Cable Color	Board Pin
SDA	1	green	A4
GND	2	black	GND
SCL	3	yellow	A5
VDD	4	red	3.3V

Arduino Micro

SHT4X	SHT4X Pin	Cable Color	Board Pin
SDA	1	green	D2/SDA
GND	2	black	GND
SCL	3	yellow	~D3/SCL
VDD	4	red	3.3V

Arduino Mega 2560

SHT4X	SHT4X Pin	Cable Color	Board Pin
SDA	1	green	D20/SDA
GND	2	black	GND
SCL	3	yellow	D21/SCL
VDD	4	red	3.3V

ESP32 DevKitC

SHT4X	SHT4X Pin	Cable Color	Board Pin
SDA	1	green	GPIO 21
GND	2	black	GND
SCL	3	yellow	GPIO 22
VDD	4	red	3V3

Quick Start

1. Install the libraries and dependencies according to Installation of the library

2. Connect the SHT4X sensor to your Arduino as explained in Sensor wiring

3. Open the exampleUsage sample project within the Arduino IDE:

   File ➔ Examples ➔ Sensirion I2C SHT4X ➔ exampleUsage

   The provided example is working with a SHT40, I²C address 0x44. In order to use the code with another product or I²C address you need to change it in the code of examples/exampleUsage. You find the list with pre-defined addresses in src/SensirionI2cSht4X.h.

4. Click the Upload button in the Arduino IDE or Sketch ➔ Upload

5. When the upload process has finished, open the Serial Monitor or Serial Plotter via the Tools menu to observe the measurement values. Note that the Baud Rate in the used tool has to be set to 115200 baud.

Contributing

Contributions are welcome!

We develop and test this driver using our company internal tools (version control, continuous integration, code review etc.) and automatically synchronize the master branch with GitHub. But this doesn't mean that we don't respond to issues or don't accept pull requests on GitHub. In fact, you're very welcome to open issues or create pull requests :)

This Sensirion library uses clang-format to standardize the formatting of all our .cpp and .h files. Make sure your contributions are formatted accordingly:

The -i flag will apply the format changes to the files listed.

clang-format -i src/*.cpp src/*.h

Note that differences from this formatting will result in a failed build until they are fixed. :

License

See LICENSE.

arduino-i2c-sht4x's Issues

ESP32 measureHighPrecision(): Not enough data received

measureHighPrecision(): Not enough data received

Support for SHT40-B sensors with alternative i2c address

Could you please add support for SHT40-B sensors that have the alternative i2c address 0x45?

Currently it is hardcoded in SensirionI2CSht4x.cpp, line 44:
#define SHT4X_I2C_ADDRESS 0x44

You could just add a uint8_t field to the sensor object and use either the constructor or begin(...) method with the current address as the default. This would even be backward compatible with the current library version.

Small mistake in documentation

In class SensirionI2CSht4x.cpp the documentation says (line 53):

* @param serial Arduino stream object to be communicated with.

Should be:

* @param i2cBus Arduino stream object to be communicated with.

Incompatibility Issue

I am currently undertaking a project involving the integration of the SHT40I-AD1B-R2 temperature sensor with an ESP32 C3 Mini, as depicted in the attached image. I am employing the Sensirion Arduino-I2C-SHT4x library to facilitate this integration. Unfortunately, I have encountered a significant issue where the library fails to read the data from the sensor, specifically, it does not detect or recognize the SHT sensor. The system consistently returns an error message.

Given this context, I would greatly appreciate any guidance or recommendations you might have regarding this problem. Could there be specific configurations or aspects of the SHT40I that are not compatible with your library? Any insights or potential solutions to enable successful communication between the sensor and the microcontroller would be immensely helpful.

Thank you for your assistance.