diff --git a/minidisc_namer_RM-D27M.ino b/minidisc_namer_RM-D27M.ino
index a234058..3063f50 100644
--- a/minidisc_namer_RM-D27M.ino
+++ b/minidisc_namer_RM-D27M.ino
@@ -1,7 +1,7 @@
 // modified for use with Sony RM-D27M
 // based on https://hackaday.io/project/165504-sony-minidisc-namer by smartroad
 
-#include <IRremote.h> // Muss installiert werden. Evtl alte Version. Siehe https://github.com/Arduino-IRremote/Arduino-IRremote
+#include <IRremote.h> // Muss installiert werden. Funktioniert mit v2.5.0 Siehe https://github.com/Arduino-IRremote/Arduino-IRremote
 #include "defines.h"
 
 IRsend irsend;
@@ -9,24 +9,100 @@ IRsend irsend;
 char inputChars[64];
 byte charCount = 0;
 
-byte mode = 0; // Capticals = 0, Lowercase = 1
+byte mode = 0; // Capitals = 0, Lowercase = 1
 byte targetMode = 0;
 boolean commandMode = true; // True = control playback | False = name entry mode
 
 int totalCount = 0;
 byte blockCount = 0;
 
+// define the IT sendPin:
+uint8_t tSendPin = 4; // IO4 auf AZ D1
+
+/* start testing code for hardware button*/
+// constants won't change. They're used here to set pin numbers:
+uint8_t buttonPin = 14; // the number of the pushbutton pin
+uint8_t ledPin = 2;     // the number of the LED pin
+
+// variables will change:
+uint8_t buttonState = 0; // variable for reading the pushbutton status
+/* end testing code */
+
 void setup()
 {
-  Serial.begin(9600);
+  pinMode(2, OUTPUT);
+  // Initialize serial monitor:
+  Serial.begin(115200);
   while (!Serial)
     ;
-  pinMode(9, OUTPUT);
-  digitalWrite(9, HIGH);
-  helpText();
+  // helpText();
+  pinMode(tSendPin, OUTPUT);
+  digitalWrite(tSendPin, LOW);
+  /* start testing code */
+  // initialize the LED pin as an output:
+  pinMode(ledPin, OUTPUT);
+  // initialize the pushbutton pin as an input:
+  pinMode(buttonPin, INPUT);
+  digitalWrite(ledPin, HIGH);
+  /* end testing code */
 }
 
 void loop()
+{
+  // blink(); //! Der Loop wird gerade nur einmal ausgeführt und stoppt bei der serial monitor eingabe. Bei jeder Eingabe erfolgt ein neue Loop. Alle test-Funktionen laufen durch.
+  // simpleButtonTest();
+  buttonPlayTest();
+
+  // oldSerialInput();
+}
+
+void simpleButtonTest()
+{
+  /* start testing code */
+  // read the state of the pushbutton value:
+  buttonState = digitalRead(buttonPin);
+
+  // check if the pushbutton is pressed. If it is, the buttonState is HIGH:
+  if (buttonState == HIGH)
+  {
+    // write to serial monitor:
+    Serial.println(F("button state is HIGH"));
+    // turn LED on:
+    digitalWrite(ledPin, HIGH);
+  }
+  else
+  {
+    // turn LED off:
+    digitalWrite(ledPin, LOW);
+  }
+  /* end testing code */
+}
+
+void buttonPlayTest()
+{
+  /* start testing code */
+  // read the state of the pushbutton value:
+  buttonState = digitalRead(buttonPin);
+
+  // check if the pushbutton is pressed. If it is, the buttonState is HIGH:
+  if (buttonState == HIGH)
+  {
+    // write to serial monitor:
+    Serial.println(F("button state is HIGH"));
+    // turn LED on:
+    digitalWrite(ledPin, HIGH);
+    Serial.println(F("Play"));
+    sendButton(PLAY);
+  }
+  else
+  {
+    // turn LED off:
+    digitalWrite(ledPin, LOW);
+  }
+  /* end testing code */
+}
+
+void oldSerialInput()
 {
 
   if (commandMode)
@@ -115,12 +191,16 @@ void loop()
       else if (serialChar == '1')
       {
         Serial.print(F("1"));
-        sendButton(NUMBER1);
+        // sendButton(NUMBER1);
+        digitalWrite(ledPin, HIGH);
+        Serial.print(F("set ledPin HIGH"));
       }
       else if (serialChar == '2')
       {
         Serial.print(F("2"));
-        sendButton(NUMBER2);
+        // sendButton(NUMBER2);
+        digitalWrite(ledPin, LOW);
+        Serial.print(F("set ledPin LOW"));
       }
       else if (serialChar == '3')
       {
@@ -677,13 +757,13 @@ void sendCmd(int command, byte repeats)
 
 void sendButton(int bts)
 {
-  digitalWrite(9, LOW);
+  digitalWrite(tSendPin, HIGH);
   for (int i = 0; i < 3; i++)
   {
-    irsend.sendSony(bts, 12);
+    irsend.sendSony(bts, 12); //! Hier wird das Command gesendet! Es besteht aus dem command und der bitlänge.
     delay(25);
   }
-  digitalWrite(9, HIGH);
+  digitalWrite(tSendPin, LOW);
 }
 
 void sendNumCmd(int command, byte repeats)
@@ -756,3 +836,31 @@ boolean nameCheck()
   else
     return 0;
 }
+
+void blink()
+{
+  /* start testing code */
+  // read the state of the pushbutton value:
+  buttonState = digitalRead(buttonPin);
+
+  // check if the pushbutton is pressed. If it is, the buttonState is HIGH:
+  if (buttonState == HIGH)
+  {
+    // write to serial monitor:
+    Serial.println(F("button state is HIGH"));
+    // turn LED on:
+    digitalWrite(ledPin, HIGH);
+  }
+  else
+  {
+    // turn LED off:
+    digitalWrite(ledPin, LOW);
+  }
+  /* end testing code */
+
+  Serial.print(F("blink"));
+  // digitalWrite(ledPin, HIGH);  // turn the LED on (HIGH is the voltage level)
+  // delay(1000);                      // wait for a second
+  // digitalWrite(ledPin, LOW);   // turn the LED off by making the voltage LOW
+  // delay(1000);
+}