Sensirion Raspberry Pi I2C STS4x Driver

This document explains how to set up the STS4x sensor to run on a Raspberry Pi using the provided code.

Click here to learn more about the STS4x Sensor and Evaluation Kit.

Setup Guide

Connecting the Sensor

Your sensor has the four different connectors: VCC, GND, SDA, SCL. Use the following pins to connect your STS4x:

STS4x	Raspberry Pi
VCC	Pin 1 (3.3V)
GND	Pin 6
SDA	Pin 3
SCL	Pin 5

Raspberry Pi

• Install the Raspberry Pi OS on to your Raspberry Pi
• Enable the I2C interface in the raspi-config
• Download the driver for the Sensirion Github Page and extract the .zip on your Raspberry Pi
• Compile the driver

  1. Open a terminal

  2. Navigate to the driver directory. E.g. cd ~/raspberry-pi-i2c-sts4x

  3. Run the make command to compile the driver

     Output:

     rm -f sts4x_i2c_example_usage
     cc -Os -Wall -fstrict-aliasing -Wstrict-aliasing=1 -Wsign-conversion -fPIC -I. -o sts4x_i2c_example_usage  sts4x_i2c.h sts4x_i2c.c sensirion_i2c_hal.h sensirion_i2c.h sensirion_i2c.c \
     	sensirion_i2c_hal.c sensirion_config.h sensirion_common.h sensirion_common.c sts4x_i2c_example_usage.c
     

• Test your connected sensor

  • Run ./sts4x_i2c_example_usage in the same directory you used to compile the driver.

    Output:

    Serial number: 272952127
    Temperature: 25.09 °C
    Temperature: 25.08 °C
    Temperature: 25.08 °C
    Temperature: 25.10 °C 
    Temperature: 25.08 °C
    ...
    

Troubleshooting

Initialization failed

• Ensure that you connected the sensor correctly: All cables are fully plugged in and connected to the correct pin.
• Ensure that I2C is enabled on the Raspberry Pi. For this redo the steps on "Enable the I2C interface in the raspi-config" in the guide above.
• Ensure that your user account has read and write access to the I2C device. If it only works with user root (sudo ./sts4x_i2c_example_usage), it's typically due to wrong permission settings.