Example Code for Arduino - I2C Address Detection

Prepare

Hardware Prepare

• Arduino UNO R4 WiFi (SKU:DFR1084) ×1
• Gravity: STCC4 CO2 Sensor（SKU:SEN0678）×1
• Gravity to Qwiic Adapter x1

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

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：