The output is 0, can not read the data

Need Help With My Project
1

Hello everyone, I am an esp32 newbie and I am working on a smart water tank project. Let me introduce:
Hardware:
ESP32 DEVKIT V1
ESP32S 30P EXPANSION BOARD
MQ-135 AIR SENSOR
MQ-7 AIR SENSOR
I2C BOARD 20X2

Source Code

#define BLYNK_PRINT Serial

#define BLYNK_TEMPLATE_ID "TMPL6v9JuHYAV"
#define BLYNK_TEMPLATE_NAME "Smart Water Tank"
#define BLYNK_AUTH_TOKEN "VRd-62sso0mg1tDc214HyxoMrXbvr8Og"

#include <WiFi.h>
#include <WiFiClient.h>
#include <BlynkSimpleEsp32.h>

#include <LiquidCrystal_I2C.h>

int lcdColumns = 16;
int lcdRows = 2;

int MQ7sensorPin = 15;
int MQ135sensorPin = 13;
int MQ7sensorData;
int MQ135sensorData;

LiquidCrystal_I2C lcd(0x27, lcdColumns, lcdRows);  

BlynkTimer timer;

char auth[] = "VRd-62sso0mg1tDc214HyxoMrXbvr8Og";
char ssid[] = "LINKSYS";
char pass[] = "ab123456";


void sendSensor()
{
  Blynk.virtualWrite(V0,MQ7sensorData);
  Blynk.virtualWrite(V1,MQ135sensorData);


}


void setup() 
{
  lcd.init();    // initialize LCD
  lcd.backlight();     // turn on LCD backlight 
  
  Serial.begin(115200);
  Blynk.begin(auth, ssid, pass);

  pinMode(MQ7sensorPin,INPUT);       
  pinMode(MQ135sensorPin,INPUT);  


  timer.setInterval(1000L, sendSensor);

}

void loop() 
{
  MQ7sensorData = analogRead(MQ7sensorPin);
  lcd.setCursor(0,0);   
  lcd.print("CO:");
  lcd.setCursor(6,0); 
  lcd.print(MQ7sensorData);
  lcd.setCursor(13,0);   
  lcd.println("PPM");
  
  MQ135sensorData = analogRead(MQ135sensorPin);
  lcd.setCursor(0,1);     
  lcd.print("CO2:");
  lcd.setCursor(6,1); 
  lcd.print(MQ135sensorData);
  lcd.setCursor(13, 1); 
  lcd.println("PPM");
  delay(1000);

  Blynk.run();
  timer.run();  
}

The problem is when I // Blynk.begin(auth, ssid, pass); and //Blynk.run(); , IC2 BORAD can display the data.

WhatsApp Image 2024-06-14 at 3.02.02 PM
WhatsApp Image 2024-06-14 at 3.02.02 PM1152×2048 315 KB

When I add these two pieces of code to the program, it just displays 0 on the i2c board.

How to fix it? thank you all

2

You can’t use ADC2 pins at the same time as WiFi.

Read this, and also take note of the “keep your void loop clean” comments too…

Pete.

3

So, is this the new program?

#define BLYNK_PRINT Serial

#define BLYNK_TEMPLATE_ID "TMPL6v9JuHYAV"
#define BLYNK_TEMPLATE_NAME "Smart Water Tank"
#define BLYNK_AUTH_TOKEN "VRd-62sso0mg1tDc214HyxoMrXbvr8Og"

#include <WiFi.h>
#include <WiFiClient.h>
#include <BlynkSimpleEsp32.h>

#include <LiquidCrystal_I2C.h>

int lcdColumns = 16;
int lcdRows = 2;

LiquidCrystal_I2C lcd(0x27, lcdColumns, lcdRows);  

BlynkTimer timer;

char auth[] = "VRd-62sso0mg1tDc214HyxoMrXbvr8Og";
char ssid[] = "LINKSYS";
char pass[] = "ab123456";


void sendSensor()
{
  int MQ7sensorData = analogRead(15);
  Blynk.virtualWrite(V0, MQ7sensorData);
  int MQ135sensorData = analogRead(13);
  Blynk.virtualWrite(V1, MQ135sensorData);

  lcd.setCursor(0,0);   
  lcd.print("CO:");
  lcd.setCursor(6,0); 
  lcd.print(MQ7sensorData);
  lcd.setCursor(13,0);   
  lcd.println("PPM");
  
  lcd.setCursor(0,1);     
  lcd.print("CO2:");
  lcd.setCursor(6,1); 
  lcd.print(MQ135sensorData);
  lcd.setCursor(13, 1); 
  lcd.println("PPM");
  delay(1000);
}


void setup() 
{
  lcd.init();    // initialize LCD
  lcd.backlight();     // turn on LCD backlight 
  
  Serial.begin(115200);
  Blynk.begin(auth, ssid, pass);

  pinMode(15,INPUT);       
  pinMode(13,INPUT);  


  timer.setInterval(1000L, sendSensor);

}

void loop() 
{
  Blynk.run();
  timer.run();  
}
4

I’ve been trying but it doesn’t work, it keeps showing 0

5

You’re still using the same ADC2 pins. You need to swap your sensors to ADC1 pins and update your sketch.
Also, why have you dropped the use of the pin aliases and put the GPIO numbers in your digitalRead statements?

Pete.

6

It works, thank you so much!! :grinning: