diff --git a/doku.txt b/doku.txt
new file mode 100644
index 0000000..cc2fb63
--- /dev/null
+++ b/doku.txt
@@ -0,0 +1,3 @@
+Hardware Timer didnt work https://github.com/khoih-prog/ESP8266TimerInterrupt#why-using-isr-based-hardware-timer-interrupt-is-better
+=> Software Timer https://ullisroboterseite.de/esp8266-timing.html#timer
+
diff --git a/src/main.cpp b/src/main.cpp
index 0e8bc5b..201b3d4 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -12,7 +12,7 @@ uint32_t c;
 
 uint32_t m=0;
 void timerCallback(void *pArg)
-{ 
+{
   *((int *) pArg) += 1;
   
   Serial.print("hallo\n");
@@ -183,7 +183,7 @@ void setup() {
     ESP.restart();
   }
  
-  os_timer_setfn(&Timer1, timerCallback, &c);
+  os_timer_setfn(&Timer1, timerCallback, NULL);
   os_timer_arm(&Timer1, 1000, true);
 
   Serial.println("Ready");