diff --git a/examples/Alcoholimeter/Alcoholimeter.ino b/examples/Alcoholimeter/Alcoholimeter.ino
index 16444bb..f490e3d 100644
--- a/examples/Alcoholimeter/Alcoholimeter.ino
+++ b/examples/Alcoholimeter/Alcoholimeter.ino
@@ -23,7 +23,7 @@
 //Definitions
 #define placa "Arduino UNO"
 #define Voltage_Resolution 5
-#define pin A0 //Analog input 0 of your arduino
+#define pin A3 //Analog input 3 of your arduino
 #define type "MQ-3" //MQ3
 #define ADC_Bit_Resolution 10 // For arduino UNO/MEGA/NANO
 //#define calibration_button 13 //Pin to calibrate your sensor
diff --git a/examples/Calibration/Calibration.ino b/examples/Calibration/Calibration.ino
index ef52e71..048d199 100644
--- a/examples/Calibration/Calibration.ino
+++ b/examples/Calibration/Calibration.ino
@@ -19,7 +19,7 @@
 //Definitions
 #define placa "Arduino UNO"
 #define Voltage_Resolution 5
-#define pin A2 //Analog input 0 of your arduino
+#define pin A2 //Analog input 2 of your arduino
 #define type "MQ-2" //MQ2
 #define ADC_Bit_Resolution 10 // For arduino UNO/MEGA/NANO
 
diff --git a/examples/ESP8266/ESP8266.ino b/examples/ESP8266/ESP8266.ino
index 8786281..54b23d1 100644
--- a/examples/ESP8266/ESP8266.ino
+++ b/examples/ESP8266/ESP8266.ino
@@ -25,9 +25,9 @@
 //Definitions
 #define placa "ESP8266" //NodeMcu, WeMos D1, TTGo, ESP32.. etc
 #define Voltage_Resolution 3.3
-#define pin A0 //Analog input 0 of your arduino
+#define pin A0 //Analog input 0 of your ESP Board
 #define type "MQ-3" //MQ3
-#define ADC_Bit_Resolution 10 // For arduino UNO/MEGA/NANO
+#define ADC_Bit_Resolution 10 // For ESP8266
 
 //Declare Sensor
 MQUnifiedsensor MQ3(placa, Voltage_Resolution, ADC_Bit_Resolution, pin, type);
diff --git a/examples/smokeDetector/smokeDetector.ino b/examples/smokeDetector/smokeDetector.ino
index b8a318d..ba37b91 100644
--- a/examples/smokeDetector/smokeDetector.ino
+++ b/examples/smokeDetector/smokeDetector.ino
@@ -19,7 +19,7 @@
 //Definitions
 #define placa "Arduino UNO"
 #define Voltage_Resolution 5
-#define pin A4 //Analog input 0 of your arduino
+#define pin A4 //Analog input 4 of your arduino
 #define type "MQ-4" //MQ4
 #define ADC_Bit_Resolution 10 // For arduino UNO/MEGA/NANO
 #define RatioMQ4CleanAir 4.4  //RS / R0 = 4.4 ppm