HI, Can you help me with my code please? I am currently making a project to read SO2 and CO2 gas using sensors MQ136 and MQ136 and NodeMCU ESP8266. but the result is 0. This is my code

```
#include <ESP8266WiFi.h>
#include "Arduino.h"
//MQ136
int mq136 = A0;
int Rload136= 10000;
float rO136 = 18897;
double ppm136 = 50;
float a136 = 36.77992237;
float b136 = -3.500061191;
//MQ135
int mq135 = 2;
int Rload135= 20000;
float rO135 = 2842;
double ppm135 = 411.28;
float a135 = 110.7432567;
float b135 = -2.856935538;
unsigned long previousMillis = 0;
const long interval = 5000;
void setup()
{
Serial.begin(9600);
}
void loop(){
int adcRaw136 = analogRead(mq136);
double rS136 = ((1023.0 * Rload136)/adcRaw136)-Rload136;
float rSrO136 = rS136/rO136;
float ppm136 = a136 * pow((float)rS136/(float)rO136, b136);
int adcRaw135 = analogRead(mq135);
double rS135 = ((1023.0 * Rload135)/adcRaw135)-Rload135;
float rSrO135 = rS135/rO135;
float ppm135 = a135 * pow((float)rS135/(float)rO135, b135);
delay (5000);
unsigned long currentMillis = millis();
if (currentMillis - previousMillis >= interval)
{
previousMillis = currentMillis;
Serial.print ("rSrO SO2 = ");
Serial.println (rSrO136);
Serial.print ("SO2 = ");
Serial.println (ppm136);
Serial.print ("rSrO CO2 = ");
Serial.println (rSrO135);
Serial.print ("CO2 = ");
Serial.println (ppm135);
}
}
```

and this is the result

```
rSrO SO2 = 270.15
SO2 = 0.00
rSrO CO2 = 0.00
CO2 = inf
rSrO SO2 = 179.92
SO2 = 0.00
rSrO CO2 = 0.00
CO2 = inf
rSrO SO2 = 179.92
SO2 = 0.00
rSrO CO2 = 0.00
CO2 = inf
rSrO SO2 = 270.15
SO2 = 0.00
rSrO CO2 = 0.00
CO2 = inf
rSrO SO2 = 179.92
SO2 = 0.00
rSrO CO2 = 0.00
CO2 = inf
rSrO SO2 = 59.62
SO2 = 0.00
rSrO CO2 = 0.00
CO2 = inf
rSrO SO2 = 59.62
SO2 = 0.00
rSrO CO2 = 0.00
CO2 = inf
rSrO SO2 = 59.62
SO2 = 0.00
rSrO CO2 = 0.00
CO2 = inf
rSrO SO2 = 59.62
SO2 = 0.00
rSrO CO2 = 0.00
CO2 = inf
rSrO SO2 = 59.62
SO2 = 0.00
rSrO CO2 = 0.00
CO2 = inf
rSrO SO2 = 179.92
SO2 = 0.00
rSrO CO2 = 0.00
CO2 = inf
rSrO SO2 = 67.14
SO2 = 0.00
rSrO CO2 = 0.00
CO2 = inf
rSrO SO2 = 59.62
SO2 = 0.00
rSrO CO2 = 0.00
CO2 = inf
rSrO SO2 = 59.62
SO2 = 0.00
rSrO CO2 = 0.00
CO2 = inf
rSrO SO2 = 59.62
SO2 = 0.00
rSrO CO2 = 0.00
CO2 = inf
rSrO SO2 = 59.62
SO2 = 0.00
rSrO CO2 = 0.00
CO2 = inf
rSrO SO2 = 59.62
SO2 = 0.00
rSrO CO2 = 0.00
CO2 = inf
rSrO SO2 = 59.62
SO2 = 0.00
rSrO CO2 = 0.00
CO2 = inf
rSrO SO2 = 59.62
SO2 = 0.00
rSrO CO2 = 0.00
CO2 = inf
rSrO SO2 = 67.14
SO2 = 0.00
rSrO CO2 = 0.00
CO2 = inf
rSrO SO2 = 59.62
SO2 = 0.00
rSrO CO2 = 0.00
CO2 = inf
rSrO SO2 = 59.62
SO2 = 0.00
rSrO CO2 = 0.00
CO2 = inf
rSrO SO2 = 59.62
SO2 = 0.00
rSrO CO2 = 0.00
CO2 = inf
```

Any help appreciated, Thank you very much