Getting Started with Gravity: STCC4 CO2 Sensor & Arduino UNO R4 WiFi: Setup & Guide

This tutorial covers setting up an Arduino UNO R4 WiFi with a Gravity: STCC4 CO2 Sensor, including hardware and software preparation, wiring, and sample code for I2C address detection. It's like learning to connect and communicate with sensors in your projects.

Prepare

Hardware Prepare

Name	SKU	Quantity	Purchase Link	Description
Arduino UNO R4 WiFi	DFR1084	1	https://www.dfrobot.com/product-2700.html	Controller
Gravity: STCC4 CO2 Sensor	SEN0678	2	https://www.dfrobot.com/product-3098.html	Sensor
Gravity to Qwiic Adapter	DFR1271	1		Adapter
Qwiic cable	Come with Qwiic Adapter	1		Cable
Gravity cable	Come with Gravity sensor	2		Cable

Software Prepare

Download Arduino IDE： Click to download Arduino IDE
Download DFRobot_STCC4 library：DFRobot_STCC4 library
Arduino IDE V1.8.19(or below) install library： How to load library
For Arduino IDE V2.0.0 (or above), please directly search and install "DFRobot_STCC4" library in the library manager.

Wiring Diagram

Prepare Wiring Diagram

Sensor	Pin	Adapter board	Pin
Gravity STCC4 CO2 Sensor	VCC	Gravity to Qwiic Adapter	VCC
Gravity STCC4 CO2 Sensor	GND	Gravity to Qwiic Adapter	GND
Gravity STCC4 CO2 Sensor	SCL	Gravity to Qwiic Adapter	SCL
Gravity STCC4 CO2 Sensor	SDA	Gravity to Qwiic Adapter	SDA

Sample code 1-I2C Address detection

Note: For the Qwiic port on Arduino UNO R4 WiFi, the identifier in the Wire library is Wire1, not the default Wire.

#include <Wire.h>
void setup() {
 Wire1.begin(); // If you need to run this code on boards other than the UNO R4 WiFi, change this line to `Wire.begin();`.
 Serial.begin(115200);
 while (!Serial); 
 Serial.println("\nI2C Scanner");
}
void loop() {
 byte error, address;
 int nDevices = 0;
 Serial.println("Scanning...");
 for (address = 1; address < 127; address++) {
   Wire1.beginTransmission(address);// If you need to run this code on boards other than the UNO R4 WiFi, change this line to `Wire.beginTransmission(address);`.
   error = Wire1.endTransmission();//error = Wire.endTransmission();
   if (error == 0) {
     Serial.print("I2C device found at address 0x");
     if (address < 16) Serial.print("0");
     Serial.println(address, HEX);
     nDevices++;
   } else if (error == 4) {
     Serial.print("Unknown error at address 0x");
     if (address < 16) Serial.print("0");
     Serial.println(address, HEX);
   }
 }
 if (nDevices == 0)
   Serial.println("No I2C devices found\n");
 else
   Serial.println("Scan complete\n");
 delay(5000); // Wait for 5 seconds before scanning again
}

Result

Serial monitor output I2C address：
Sample code 1-I2C Address detection Result

The serial monitor will display the detected I2C address of the connected sensor, such as I2C device found at address 0x64.

Example Code for Arduino - I2C Address Detection