diff --git a/cpu/avr/rtimer-arch.c b/cpu/avr/rtimer-arch.c
index 07a643018..c3f8f0220 100644
--- a/cpu/avr/rtimer-arch.c
+++ b/cpu/avr/rtimer-arch.c
@@ -225,3 +225,112 @@ rtimer_arch_schedule(rtimer_clock_t t)
   SREG = sreg;
 #endif /* RTIMER_ARCH_PRESCALER */
 }
+
+#if RDC_CONF_MCU_SLEEP
+/*---------------------------------------------------------------------------*/
+void
+rtimer_arch_sleep(rtimer_clock_t howlong)
+{
+/* Deep Sleep for howlong rtimer ticks. This will stop all timers except
+ * for TIMER2 which can be clocked using an external crystal.
+ * Unfortunately this is an 8 bit timer; a lower prescaler gives higher
+ * precision but smaller maximum sleep time.
+ * Here a maximum 128msec (contikimac 8Hz channel check sleep) is assumed.
+ * The rtimer and system clocks are adjusted to reflect the sleep time.
+ */
+#include <avr/sleep.h>
+#include <dev/watchdog.h>
+uint32_t longhowlong;
+#if AVR_CONF_USE32KCRYSTAL
+/* Save TIMER2 configuration if clock.c is using it */
+    uint8_t savedTCNT2=TCNT2, savedTCCR2A=TCCR2A, savedTCCR2B = TCCR2B, savedOCR2A = OCR2A;
+#endif
+    cli();
+	watchdog_stop();
+	set_sleep_mode(SLEEP_MODE_PWR_SAVE);
+
+/* Set TIMER2 clock asynchronus from external source, CTC mode */
+    ASSR |= (1 << AS2);
+    TCCR2A =(1<<WGM21);
+/* Set prescaler and TIMER2 output compare register */
+#if 0    //Prescale by 1024 -   32 ticks/sec, 8 seconds max sleep
+    TCCR2B =((1<<CS22)|(1<<CS21)|(1<<CS20));
+	longhowlong=howlong*32UL; 
+#elif 0  // Prescale by 256 -  128 ticks/sec, 2 seconds max sleep
+	TCCR2B =((1<<CS22)|(1<<CS21)|(0<<CS20));
+	longhowlong=howlong*128UL;
+#elif 0  // Prescale by 128 -  256 ticks/sec, 1 seconds max sleep
+	TCCR2B =((1<<CS22)|(0<<CS21)|(1<<CS20));
+	longhowlong=howlong*256UL;
+#elif 0  // Prescale by  64 -  512 ticks/sec, 500 msec max sleep
+	TCCR2B =((1<<CS22)|(0<<CS21)|(0<<CS20));
+	longhowlong=howlong*512UL;
+#elif 1  // Prescale by  32 - 1024 ticks/sec, 250 msec max sleep
+	TCCR2B =((0<<CS22)|(1<<CS21)|(1<<CS20));
+	longhowlong=howlong*1024UL;
+#elif 0  // Prescale by   8 - 4096 ticks/sec, 62.5 msec max sleep
+	TCCR2B =((0<<CS22)|(1<<CS21)|(0<<CS20));
+	longhowlong=howlong*4096UL;
+#else    // No Prescale -    32768 ticks/sec, 7.8 msec max sleep
+	TCCR2B =((0<<CS22)|(0<<CS21)|(1<<CS20));
+	longhowlong=howlong*32768UL;
+#endif
+	OCR2A = longhowlong/RTIMER_ARCH_SECOND;
+
+/* Reset timer count, wait for the write (which assures TCCR2x and OCR2A are finished) */
+    TCNT2 = 0; 
+    while(ASSR & (1 << TCN2UB));
+
+/* Enable TIMER2 output compare interrupt, sleep mode and sleep */
+    TIMSK2 |= (1 << OCIE2A);
+    SMCR |= (1 <<  SE);
+	sei();
+	ENERGEST_OFF(ENERGEST_TYPE_CPU);
+	if (OCR2A) sleep_mode();
+	  //...zzZZZzz...Ding!//
+
+/* Disable sleep mode after wakeup, so random code cant trigger sleep */
+    SMCR  &= ~(1 << SE);
+
+/* Adjust rtimer ticks if rtimer is enabled. TIMER3 is preferred, else TIMER1 */
+#if RTIMER_ARCH_PRESCALER
+#ifdef TCNT3
+    TCNT3 += howlong;
+#else
+    TCNT1 += howlong;
+#endif
+#endif
+	ENERGEST_ON(ENERGEST_TYPE_CPU);
+
+#if AVR_CONF_USE32KCRYSTAL
+/* Restore clock.c configuration */
+    cli();
+    TCCR2A = savedTCCR2A;
+    TCCR2B = savedTCCR2B;
+    OCR2A  = savedOCR2A;
+    TCNT2  = savedTCNT2;
+    sei();
+#else
+/* Disable TIMER2 interrupt */
+    TIMSK2 &= ~(1 << OCIE2A);
+#endif
+    watchdog_start();
+
+/* Adjust clock.c for the time spent sleeping */
+    extern void clock_adjust_ticks(uint16_t howmany);
+	longhowlong=CLOCK_CONF_SECOND;
+	longhowlong*=howlong;
+    clock_adjust_ticks(longhowlong/RTIMER_ARCH_SECOND);
+
+}
+#if !AVR_CONF_USE32KCRYSTAL
+/*---------------------------------------------------------------------------*/
+/* TIMER2 Interrupt service */
+
+ISR(TIMER2_COMPA_vect)
+{
+//    TIMSK2 &= ~(1 << OCIE2A);       //Just one interrupt needed for waking
+}
+#endif /* !AVR_CONF_USE32KCRYSTAL */
+#endif /* RDC_CONF_MCU_SLEEP */
+
diff --git a/cpu/avr/rtimer-arch.h b/cpu/avr/rtimer-arch.h
index 533ea0507..b53387c4d 100644
--- a/cpu/avr/rtimer-arch.h
+++ b/cpu/avr/rtimer-arch.h
@@ -61,4 +61,5 @@
 #define rtimer_arch_now() (0)
 #endif
 
+void rtimer_arch_sleep(rtimer_clock_t howlong);
 #endif /* __RTIMER_ARCH_H__ */