Biomebubble: C code for Sensirion Sensor Read out on Pi Terminal

This document explains how to set up the Sen sensors to run on a Raspberry Pi using the provided code, and printing the readings to the terminal.

Supported sensors

• SFA3X
• SCD30
• SEN44
• SEN55
• SEN66

Setup Guide

Connecting the Sensor

The sensor board cable has the five different connectors: VCC, GND, SDA, SCL, GND Use the following pins to connect your Board

Board	Raspberry Pi	Jumper Wire
VCC	Pin 2 (5V)	Red
GND	Pin 6	Black
SDA	Pin 3	Green
SCL	Pin 5	Yellow
GND	Pin 9 (GND for I2C)	Blue

Pin	Name	Description	Comments
1	GND	Ground
2	GND	Ground
3	SCL	I2C: Serial clock input	TTL 5V and LVTTL 3.3V compatible
4	SDA	I2C: Serial data input / output	TTL 5V and LVTTL 3.3V compatible
5	NC	Do not connect

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 Sensor Board and extract the .zip on your Raspberry Pi
• Compile the driver

  1. Open a terminal

  2. Navigate to the driver directory. E.g. cd ~/Biomebubble/Sensor-examble

  3. Run the ./Build script to check for updates, make sure Build essential tools are installed and compile the driver

     Output:

     rm -f main.o sensirion_i2c_hal.o sensirion_i2c.o sensirion_common.o sen44_i2c.o scd30_i2c.o sfa3x_i2c.o sen66_i2c.o sen5x_i2c.o test-sensors
     gcc -Wall -O2 -I../include -c main.c -o main.o
     gcc -Wall -O2 -I../include -c ../src/sensirion_i2c_hal.c -o sensirion_i2c_hal.o
     gcc -Wall -O2 -I../include -c ../src/sensirion_i2c.c -o sensirion_i2c.o
     gcc -Wall -O2 -I../include -c ../src/sensirion_common.c -o sensirion_common.o
     gcc -Wall -O2 -I../include -c ../src/sen44_i2c.c -o sen44_i2c.o
     gcc -Wall -O2 -I../include -c ../src/scd30_i2c.c -o scd30_i2c.o
     gcc -Wall -O2 -I../include -c ../src/sfa3x_i2c.c -o sfa3x_i2c.o
     gcc -Wall -O2 -I../include -c ../src/sen66_i2c.c -o sen66_i2c.o
     gcc -Wall -O2 -I../include -c ../src/sen5x_i2c.c -o sen5x_i2c.o
     gcc -Wall -O2 -I../include -o test-sensors main.o sensirion_i2c_hal.o sensirion_i2c.o sensirion_common.o sen44_i2c.o scd30_i2c.o sfa3x_i2c.o sen66_i2c.o sen5x_i2c.o
     # Delete object files after linking
     rm -f main.o sensirion_i2c_hal.o sensirion_i2c.o sensirion_common.o sen44_i2c.o scd30_i2c.o sfa3x_i2c.o sen66_i2c.o sen5x_i2c.o
     
     

• Test your connected sensor
  • Run ./test-sensors in the same directory you used to compile the driver.

Resources:

• Sensirion Site
• Sensirion Github
• Sen44 Docs
• SCD30 Docs
• SFA30 Docs
• SEN66 Docs