diff --git a/apps/arduino/arduino-process.c b/apps/arduino/arduino-process.c
index 1ad5ce548..4f1a50102 100644
--- a/apps/arduino/arduino-process.c
+++ b/apps/arduino/arduino-process.c
@@ -59,7 +59,7 @@
 #include "project-conf.h"
 
 
-#define DEBUG 1
+#define DEBUG 0
 #if DEBUG
 #include <stdio.h>
 #define PRINTF(...) printf(__VA_ARGS__)
@@ -88,23 +88,23 @@ void
 mcu_sleep_init(void)
 {
 	mcusleepcycleval=mcusleepcycle;
-	mcu_sleep_disable();
+    mcu_sleep_disable(); // if a shell is active we can type 
 }
 void
 mcu_sleep_disable(void)
 {
-	mcusleep=0;
+	mcusleep=2;
     mcu_sleep_off();
 }
 void
 mcu_sleep_enable(void)
 {
-	mcusleep=1;
+	mcusleep=0;
 }
 void
 mcu_sleep_on(void)
 {
-	if(mcusleep){
+	if(mcusleep == 0){
 		mcusleepcycle= mcusleepcycleval;
 	}
 }
@@ -127,13 +127,12 @@ PROCESS(arduino_sketch, "Arduino Sketch Wrapper");
 #ifndef LOOP_INTERVAL
 #define LOOP_INTERVAL		(1 * CLOCK_SECOND)
 #endif
-#define START_MCUSLEEP		(5 * CLOCK_SECOND)
+#define START_MCUSLEEP		(10 * CLOCK_SECOND)
 
 PROCESS_THREAD(arduino_sketch, ev, data)
 {
   static struct etimer loop_periodic_timer;
   static struct etimer start_mcusleep_timer;
-  static int a=0;
 
   PROCESS_BEGIN();
   adc_init ();
@@ -153,10 +152,17 @@ PROCESS_THREAD(arduino_sketch, ev, data)
       mcu_sleep_on();
     }
 #endif /* PLATFORM_HAS_BUTTON */
-    if(etimer_expired(&start_mcusleep_timer) && a == 0) {
-      PRINTF("mcusleep_timer %d",a);
-      mcu_sleep_enable();
-      a++;
+    if(etimer_expired(&start_mcusleep_timer)) {
+      PRINTF("mcusleep_timer %d\n",mcusleep);
+      if(mcusleep == 1){
+        PRINTF("mcu sleep on\n");
+        mcu_sleep_enable();
+        mcu_sleep_on();
+      }
+      if (mcusleep > 0) {
+		mcusleep--;
+      }
+      etimer_reset(&start_mcusleep_timer);
     }
 
     if(etimer_expired(&loop_periodic_timer)) {
diff --git a/apps/serial-shell/serial-shell.c b/apps/serial-shell/serial-shell.c
index f33cd9aef..1a9e25621 100644
--- a/apps/serial-shell/serial-shell.c
+++ b/apps/serial-shell/serial-shell.c
@@ -49,7 +49,7 @@
 
 #include <stdio.h>
 #include <string.h>
-
+#include "arduino-process.h"
 
 /*---------------------------------------------------------------------------*/
 PROCESS(serial_shell_process, "Contiki serial shell");
@@ -59,7 +59,7 @@ shell_default_output(const char *text1, int len1, const char *text2, int len2)
 {
   int i;
   
-  mcu_sleep_off();
+  mcu_sleep_disable();
   if(text1 == NULL) {
     text1 = "";
     len1 = 0;
@@ -78,7 +78,6 @@ shell_default_output(const char *text1, int len1, const char *text2, int len2)
     printf("%c", text2[i]);
   }
   printf("\r\n");
-  mcu_sleep_on();
 }
 /*---------------------------------------------------------------------------*/
 void
@@ -92,6 +91,7 @@ void
 shell_exit(void)
 {
 }
+
 /*---------------------------------------------------------------------------*/
 PROCESS_THREAD(serial_shell_process, ev, data)
 {
@@ -101,9 +101,8 @@ PROCESS_THREAD(serial_shell_process, ev, data)
 
   while(1) {
     PROCESS_WAIT_EVENT_UNTIL(ev == serial_line_event_message && data != NULL);
-    mcu_sleep_off();
+    mcu_sleep_disable();
     shell_input(data, strlen(data));
-    mcu_sleep_on();
   }
 
   PROCESS_END();
diff --git a/apps/shell/shell-merkur.c b/apps/shell/shell-merkur.c
index 10ba783f1..3fd619710 100644
--- a/apps/shell/shell-merkur.c
+++ b/apps/shell/shell-merkur.c
@@ -255,6 +255,6 @@ shell_merkur_init(void)
   shell_register_command(&panid_command);
   shell_register_command(&macconf_command);  
   shell_register_command(&saverfparam_command);
-  shell_register_command(&s_command);
+//  shell_register_command(&s_command);
 }
 /*---------------------------------------------------------------------------*/