diff --git a/core/dev/leds.c b/core/dev/leds.c
index b18eccb89..6394826f1 100644
--- a/core/dev/leds.c
+++ b/core/dev/leds.c
@@ -28,11 +28,12 @@
  *
  * This file is part of the Contiki operating system.
  *
- * @(#)$Id: leds.c,v 1.3 2006/10/09 14:38:23 nifi Exp $
+ * @(#)$Id: leds.c,v 1.4 2007/03/19 00:33:25 adamdunkels Exp $
  */
 
 #include "dev/leds.h"
 #include "sys/clock.h"
+#include "lib/energest.h"
 
 static unsigned char leds, invert;
 /*---------------------------------------------------------------------------*/
@@ -68,6 +69,16 @@ leds_get(void) {
 void
 leds_on(unsigned char l)
 {
+  if((l & LEDS_GREEN) && !(leds & LEDS_GREEN)) {
+    ENERGEST_ON(ENERGEST_TYPE_LED_GREEN);
+  }
+  if((l & LEDS_YELLOW) && !(leds & LEDS_YELLOW)) {
+    ENERGEST_ON(ENERGEST_TYPE_LED_YELLOW);
+  }
+  if((l & LEDS_RED) && !(leds & LEDS_RED)) {
+    ENERGEST_ON(ENERGEST_TYPE_LED_RED);
+  }
+
   leds |= l;
   show_leds();
 }
@@ -75,6 +86,16 @@ leds_on(unsigned char l)
 void
 leds_off(unsigned char l)
 {
+  
+  if((l & LEDS_GREEN) && (leds & LEDS_GREEN)) {
+    ENERGEST_OFF(ENERGEST_TYPE_LED_GREEN);
+  }
+  if((l & LEDS_YELLOW) && (leds & LEDS_YELLOW)) {
+    ENERGEST_OFF(ENERGEST_TYPE_LED_YELLOW);
+  }
+  if((l & LEDS_RED) && (leds & LEDS_RED)) {
+    ENERGEST_OFF(ENERGEST_TYPE_LED_RED);
+  }
   leds &= ~l;
   show_leds();
 }
diff --git a/core/lib/energest.c b/core/lib/energest.c
new file mode 100644
index 000000000..321ab9113
--- /dev/null
+++ b/core/lib/energest.c
@@ -0,0 +1,67 @@
+/*
+ * Copyright (c) 2007, Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the Institute nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * This file is part of the Contiki operating system.
+ *
+ * $Id: energest.c,v 1.1 2007/03/19 00:30:13 adamdunkels Exp $
+ */
+
+/**
+ * \file
+ *         A brief description of what this file is.
+ * \author
+ *         Adam Dunkels <adam@sics.se>
+ */
+
+#include "lib/energest.h"
+
+#if ENERGEST_CONF_ON
+
+energest_t energest_total_time[ENERGEST_TYPE_MAX];
+energest_t energest_current_time[ENERGEST_TYPE_MAX];
+
+/*---------------------------------------------------------------------------*/
+void
+energest_init(void)
+{
+  int i;
+  for(i = 0; i < ENERGEST_TYPE_MAX; ++i) {
+    energest_total_time[i] = 0;
+  }
+}
+/*---------------------------------------------------------------------------*/
+energest_t
+energest_type_time(int type)
+{
+  return energest_total_time[type];
+}
+/*---------------------------------------------------------------------------*/
+#else /* ENERGEST_CONF_ON */
+void energest_init(void) {}
+energest_t energest_type_time(int type) { return 0; }
+#endif /* ENERGEST_CONF_ON */
diff --git a/core/lib/energest.h b/core/lib/energest.h
new file mode 100644
index 000000000..bdace4dd9
--- /dev/null
+++ b/core/lib/energest.h
@@ -0,0 +1,87 @@
+/*
+ * Copyright (c) 2007, Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the Institute nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * This file is part of the Contiki operating system.
+ *
+ * $Id: energest.h,v 1.1 2007/03/19 00:30:18 adamdunkels Exp $
+ */
+
+/**
+ * \file
+ *         A brief description of what this file is.
+ * \author
+ *         Adam Dunkels <adam@sics.se>
+ */
+
+#ifndef __ENERGEST_H__
+#define __ENERGEST_H__
+
+typedef unsigned long energest_t;
+
+enum {
+  ENERGEST_TYPE_NONE,
+
+  ENERGEST_TYPE_CPU,
+  ENERGEST_TYPE_LPM1,
+  ENERGEST_TYPE_LPM2,
+  ENERGEST_TYPE_LPM3,
+  ENERGEST_TYPE_LPM4,
+  ENERGEST_TYPE_LED_GREEN,
+  ENERGEST_TYPE_LED_YELLOW,
+  ENERGEST_TYPE_LED_RED,
+  ENERGEST_TYPE_TRANSMIT,
+  ENERGEST_TYPE_RECEIVE,
+  
+  ENERGEST_TYPE_SENSORS,
+
+  ENERGEST_TYPE_MAX
+} energest_type;
+
+void energest_init(void);
+energest_t energest_type_time(int type);
+
+#if ENERGEST_CONF_ON
+extern energest_t energest_total_time[ENERGEST_TYPE_MAX];
+extern energest_t energest_current_time[ENERGEST_TYPE_MAX];
+
+#define ENERGEST_ON(type)  do { \
+                           energest_current_time[type] = energest_arch_now(); \
+                           } while(0)
+#define ENERGEST_OFF(type) do { \
+                           energest_total_time[type] += energest_arch_now() - \
+                           energest_current_time[type]; \
+                           } while(0)
+#else /* ENERGEST_CONF_ON */
+#define ENERGEST_ON(type) do { } while(0)
+#define ENERGEST_OFF(type) do { } while(0)
+#endif /* ENERGEST_CONF_ON */
+
+energest_t energest_arch_current_estimate(void);
+energest_t energest_arch_now(void);
+
+#endif /* __ENERGEST_H__ */
diff --git a/platform/esb/dev/esb-sensors.c b/platform/esb/dev/esb-sensors.c
index 8d99524b0..0075b6a41 100644
--- a/platform/esb/dev/esb-sensors.c
+++ b/platform/esb/dev/esb-sensors.c
@@ -28,7 +28,7 @@
  *
  * This file is part of the Contiki operating system.
  *
- * $Id: esb-sensors.c,v 1.1 2006/06/18 07:49:33 adamdunkels Exp $
+ * $Id: esb-sensors.c,v 1.2 2007/03/19 00:34:43 adamdunkels Exp $
  */
 
 /**
@@ -44,6 +44,7 @@
 #include "contiki-esb.h"
 
 HWCONF_PIN(SENSORSWITCH, 5, 5);
+
 /*---------------------------------------------------------------------------*/
 void
 esb_sensors_init(void)
@@ -56,11 +57,13 @@ void
 esb_sensors_on(void)
 {
   SENSORSWITCH_CLEAR();
+  ENERGEST_ON(ENERGEST_TYPE_SENSORS);
 }
 /*---------------------------------------------------------------------------*/
 void
 esb_sensors_off(void)
 {
   SENSORSWITCH_SET();
+  ENERGEST_OFF(ENERGEST_TYPE_SENSORS);
 }
 /*---------------------------------------------------------------------------*/
diff --git a/platform/esb/dev/tr1001-gcr.c b/platform/esb/dev/tr1001-gcr.c
index d1daaca41..2e279f02e 100644
--- a/platform/esb/dev/tr1001-gcr.c
+++ b/platform/esb/dev/tr1001-gcr.c
@@ -28,7 +28,7 @@
  *
  * This file is part of the Contiki operating system.
  *
- * @(#)$Id: tr1001-gcr.c,v 1.6 2007/03/15 21:57:35 adamdunkels Exp $
+ * @(#)$Id: tr1001-gcr.c,v 1.7 2007/03/19 00:35:23 adamdunkels Exp $
  */
 /**
  * \addtogroup esb
@@ -224,6 +224,8 @@ radio_off(void)
   onoroff = OFF;
   rxoff();
   rxclear();
+
+  ENERGEST_OFF(ENERGEST_TYPE_RECEIVE);
 }
 /*---------------------------------------------------------------------------*/
 /*
@@ -233,6 +235,8 @@ radio_off(void)
 void
 radio_on(void)
 {
+  ENERGEST_ON(ENERGEST_TYPE_RECEIVE);
+  
   onoroff = ON;
   rxon();
   rxclear();
@@ -618,6 +622,8 @@ tr1001_send(u8_t *packet, u16_t len)
 
   LOG("tr1001_send: sending %d bytes\n", len);
 
+  ENERGEST_ON(ENERGEST_TYPE_TRANSMIT);
+  
   /* Prepare the transmission. */
   prepare_transmission(NUM_SYNCHBYTES);
 
@@ -664,6 +670,8 @@ tr1001_send(u8_t *packet, u16_t len)
     rxclear();
   }
 
+  ENERGEST_OFF(ENERGEST_TYPE_TRANSMIT);
+  
   return UIP_FW_OK;
 }
 /*---------------------------------------------------------------------------*/