Arduino Seeeduino Stalker v2.3 unable to read I2C Tongdy CO2 K30

CO2 sensor K30. I have read using I2C using UNO board. Successful. Code is attached.
A4 connect to I2c data. A5 to I2C clock.

PROBLEM: when using Seeeduino Stalker V2.3
I cant read CO@ anymore.
Code is attached.

I need advice

Thank you

..Ahmad

///////////////////////// start code
#include <Wire.h>
int co2Addr = 0x68; // DEFAULT Address of the CO2 sensor, 7bits shifted left.

void setup()
{ Serial.begin(9600); // Open serial connection to report values to host
Wire.begin();
Serial.println("Start..");
delay(2000);
}

int readCO2()
{ int co2_value = 0; // We will store the CO2 value inside this variable.
Wire.beginTransmission(co2Addr); // Comm through i2c
Wire.write(0x22);
Wire.write(0x00);
Wire.write(0x08); // CO2
Wire.write(0x2A); // CO2
Wire.endTransmission(co2Addr);
delay(10);
Wire.requestFrom(co2Addr, 4);
byte i = 0;
byte buffer[4] = {0, 0, 0, 0};
while(Wire.available())
{ buffer = Wire.read();

  • i++;*
  • }*
  • co2_value = 0;*
  • co2_value |= buffer[1] & 0xFF;*
  • co2_value = co2_value << 8;*
  • co2_value |= buffer[2] & 0xFF;*
  • byte sum = 0; //Checksum Byte*
  • sum = buffer[0] + buffer[1] + buffer[2]; //Byte addition utilizes overflow*
  • if(sum == buffer[3])*
  • { // if ok Success!*
  • digitalWrite(13, LOW);*
  • return co2_value;*
  • }*
  • else*
  • { // if fail*
  • digitalWrite(13, LOW);*
  • return 0;*
  • }*
    }

void loop()
{ int co2Value ;

  • delay(1000);*
  • co2Value = readCO2();*
  • delay(1000);*
  • if(co2Value > 0)*
  • { // if ok*
  • Serial.print("xCO2 Value: ");*
  • Serial.print(co2Value);*
  • Serial.println(" ");*
  • }*
  • else*
  • { Serial.println("Chksum/Commfail"); } *
  • delay(2000);*
    }
    ////////////////////end code