diff --git a/README.md b/README.md
index 9956032..a61d955 100644
--- a/README.md
+++ b/README.md
@@ -17,7 +17,7 @@ Read in active mode.
 ```cpp
 #include "PMS.h"
 
-PMS pms(Serial);
+PMS pms(Serial1);
 PMS::DATA data;
 
 void setup()
@@ -30,16 +30,16 @@ void loop()
 {
   if (pms.read(data))
   {
-    Serial1.print("PM 1.0 (ug/m3): ");
-    Serial1.println(data.PM_AE_UG_1_0);
+    Serial.print("PM 1.0 (ug/m3): ");
+    Serial.println(data.PM_AE_UG_1_0);
 
-    Serial1.print("PM 2.5 (ug/m3): ");
-    Serial1.println(data.PM_AE_UG_2_5);
+    Serial.print("PM 2.5 (ug/m3): ");
+    Serial.println(data.PM_AE_UG_2_5);
 
-    Serial1.print("PM 10.0 (ug/m3): ");
-    Serial1.println(data.PM_AE_UG_10_0);
+    Serial.print("PM 10.0 (ug/m3): ");
+    Serial.println(data.PM_AE_UG_10_0);
 
-    Serial1.println();
+    Serial.println();
   }
 
   // Do other stuff...
@@ -62,7 +62,7 @@ Read in passive mode but not the best way (see additional remarks).
 ```cpp
 #include "PMS.h"
 
-PMS pms(Serial);
+PMS pms(Serial1);
 PMS::DATA data;
 
 void setup()
@@ -74,31 +74,31 @@ void setup()
 
 void loop()
 {
-  Serial1.println("Waking up, wait 30 seconds for stable readings...");
+  Serial.println("Waking up, wait 30 seconds for stable readings...");
   pms.wakeUp();
   delay(30000);
 
-  Serial1.println("Send read request...");
+  Serial.println("Send read request...");
   pms.requestRead();
 
-  Serial1.println("Reading data...");
+  Serial.println("Reading data...");
   if (pms.readUntil(data))
   {
-    Serial1.print("PM 1.0 (ug/m3): ");
-    Serial1.println(data.PM_AE_UG_1_0);
+    Serial.print("PM 1.0 (ug/m3): ");
+    Serial.println(data.PM_AE_UG_1_0);
 
-    Serial1.print("PM 2.5 (ug/m3): ");
-    Serial1.println(data.PM_AE_UG_2_5);
+    Serial.print("PM 2.5 (ug/m3): ");
+    Serial.println(data.PM_AE_UG_2_5);
 
-    Serial1.print("PM 10.0 (ug/m3): ");
-    Serial1.println(data.PM_AE_UG_10_0);
+    Serial.print("PM 10.0 (ug/m3): ");
+    Serial.println(data.PM_AE_UG_10_0);
   }
   else
   {
-    Serial1.println("No data.");
+    Serial.println("No data.");
   }
 
-  Serial1.println("Going to sleep for 60 seconds.");
+  Serial.println("Going to sleep for 60 seconds.");
   pms.sleep();
   delay(60000);
 }
@@ -130,4 +130,4 @@ Please consider, that delay() function in examples is a blocking function.
 Try to avoid such a solution if your project requires it (see Expert.ino example in examples directory).
 
 For more accurate measurements, you can read several samples (in passive or active mode) and calculate the average.
-> Stable data should be got at least 30 seconds after the sensor wakeup from the sleep mode because of the fan's performance.
\ No newline at end of file
+> Stable data should be got at least 30 seconds after the sensor wakeup from the sleep mode because of the fan's performance.
diff --git a/examples/Advanced/Advanced.ino b/examples/Advanced/Advanced.ino
index 6034a8f..79c96bf 100644
--- a/examples/Advanced/Advanced.ino
+++ b/examples/Advanced/Advanced.ino
@@ -1,6 +1,6 @@
 #include "PMS.h"
 
-PMS pms(Serial);
+PMS pms(Serial1);
 PMS::DATA data;
 
 void setup()
@@ -12,31 +12,31 @@ void setup()
 
 void loop()
 {
-  Serial1.println("Waking up, wait 30 seconds for stable readings...");
+  Serial.println("Waking up, wait 30 seconds for stable readings...");
   pms.wakeUp();
   delay(30000);
 
-  Serial1.println("Send read request...");
+  Serial.println("Send read request...");
   pms.requestRead();
 
-  Serial1.println("Wait max. 1 second for read...");
+  Serial.println("Wait max. 1 second for read...");
   if (pms.readUntil(data))
   {
-    Serial1.print("PM 1.0 (ug/m3): ");
-    Serial1.println(data.PM_AE_UG_1_0);
+    Serial.print("PM 1.0 (ug/m3): ");
+    Serial.println(data.PM_AE_UG_1_0);
 
-    Serial1.print("PM 2.5 (ug/m3): ");
-    Serial1.println(data.PM_AE_UG_2_5);
+    Serial.print("PM 2.5 (ug/m3): ");
+    Serial.println(data.PM_AE_UG_2_5);
 
-    Serial1.print("PM 10.0 (ug/m3): ");
-    Serial1.println(data.PM_AE_UG_10_0);
+    Serial.print("PM 10.0 (ug/m3): ");
+    Serial.println(data.PM_AE_UG_10_0);
   }
   else
   {
-    Serial1.println("No data.");
+    Serial.println("No data.");
   }
 
-  Serial1.println("Going to sleep for 60 seconds.");
+  Serial.println("Going to sleep for 60 seconds.");
   pms.sleep();
   delay(60000);
-}
\ No newline at end of file
+}
diff --git a/examples/Basic/Basic.ino b/examples/Basic/Basic.ino
index b60f109..38ed898 100644
--- a/examples/Basic/Basic.ino
+++ b/examples/Basic/Basic.ino
@@ -1,6 +1,6 @@
 #include "PMS.h"
 
-PMS pms(Serial);
+PMS pms(Serial1);
 PMS::DATA data;
 
 void setup()
@@ -13,17 +13,17 @@ void loop()
 {
   if (pms.read(data))
   {
-    Serial1.print("PM 1.0 (ug/m3): ");
-    Serial1.println(data.PM_AE_UG_1_0);
+    Serial.print("PM 1.0 (ug/m3): ");
+    Serial.println(data.PM_AE_UG_1_0);
 
-    Serial1.print("PM 2.5 (ug/m3): ");
-    Serial1.println(data.PM_AE_UG_2_5);
+    Serial.print("PM 2.5 (ug/m3): ");
+    Serial.println(data.PM_AE_UG_2_5);
 
-    Serial1.print("PM 10.0 (ug/m3): ");
-    Serial1.println(data.PM_AE_UG_10_0);
+    Serial.print("PM 10.0 (ug/m3): ");
+    Serial.println(data.PM_AE_UG_10_0);
 
-    Serial1.println();
+    Serial.println();
   }
 
   // Do other stuff...
-}
\ No newline at end of file
+}
diff --git a/examples/Expert/Expert.ino b/examples/Expert/Expert.ino
index 6179419..fee2cda 100644
--- a/examples/Expert/Expert.ino
+++ b/examples/Expert/Expert.ino
@@ -4,7 +4,7 @@
 // #define DEEP_SLEEP
 
 // GPIO2 (D4 pin on ESP-12E Development Board).
-#define DEBUG_OUT Serial1
+#define DEBUG_OUT Serial
 
 // PMS_READ_INTERVAL (4:30 min) and PMS_READ_DELAY (30 sec) CAN'T BE EQUAL! Values are also used to detect sensor state.
 static const uint32_t PMS_READ_INTERVAL = 270000;
@@ -13,12 +13,12 @@ static const uint32_t PMS_READ_DELAY = 30000;
 // Default sensor state.
 uint32_t timerInterval = PMS_READ_DELAY;
 
-PMS pms(Serial);
+PMS pms(Serial1);
 
 void setup()
 {
   // GPIO1, GPIO3 (TX/RX pin on ESP-12E Development Board)
-  Serial.begin(PMS::BAUD_RATE); 
+  Serial1.begin(PMS::BAUD_RATE); 
   DEBUG_OUT.begin(9600);
 
   // Switch to passive mode.
@@ -73,7 +73,7 @@ void readData()
   PMS::DATA data;
 
   // Clear buffer (removes potentially old data) before read. Some data could have been also sent before switching to passive mode.
-  while (Serial.available()) { Serial.read(); }
+  while (Serial1.available()) { Serial.read(); }
 
   DEBUG_OUT.println("Send read request...");
   pms.requestRead();
@@ -98,4 +98,4 @@ void readData()
   {
     DEBUG_OUT.println("No data.");
   }
-}
\ No newline at end of file
+}