Seeed Grove Manual page 11

to replace the R0 below with value of R0 tested above
void setup() {
Serial.begin(9600);
}
void loop() {
float sensor_volt;
float RS_gas;
float ratio; // Get ratio RS_GAS/RS_air
int sensorValue
sensor_volt=(float)sensorValue/1024*5.0;
RS_gas = (5.0-sensor_volt)/sensor_volt;
/*-Replace the name "R0" with the value of R0 in the demo of First
Test -*/
ratio = RS_gas/R0;
/*-------------------------------------------------------------------
----*/
Serial.print("sensor_volt =
Serial.println(sensor_volt);
Serial.print("RS_ratio =
Serial.println(RS_gas);
Serial.print("Rs/R0 =
Serial.println(ratio);
Serial.print("\n\n");
delay(1000);
}
Now, we can get the concentration of gas from the below figure
// Get value of RS in a GAS
= analogRead(A0);
// ratio = RS/R0
");
");
");
// omit *RL
8