diff --git a/apps/arduino/arduino-process.c b/apps/arduino/arduino-process.c
index b7a87c0b3..f6945a9bc 100644
--- a/apps/arduino/arduino-process.c
+++ b/apps/arduino/arduino-process.c
@@ -51,6 +51,7 @@
 
 #include "arduino-process.h"
 #include "hw_timer.h"
+#include "adc.h"
 #include "hw-arduino.h"
 
 PROCESS(arduino_sketch, "Arduino Sketch Wrapper");
@@ -60,6 +61,7 @@ PROCESS_THREAD(arduino_sketch, ev, data)
   PROCESS_BEGIN();
 
   arduino_pwm_timer_init ();
+  adc_init ();
   setup ();
   while (1) {
     loop ();
diff --git a/dev/arduino/arduino-compat.h b/dev/arduino/arduino-compat.h
index 23e417623..d3f9b58ac 100644
--- a/dev/arduino/arduino-compat.h
+++ b/dev/arduino/arduino-compat.h
@@ -84,6 +84,7 @@ extern "C" {
 
 #include "contiki.h"
 #include "hw_timer.h"
+#include "adc.h"
 
 #ifdef __cplusplus
 } // extern "C"
@@ -145,6 +146,43 @@ static inline void analogWrite(uint8_t pin, int val)
   }
 }
 
+/*
+ * turnOffPWM of arduino is implemented by hw_timer
+ */
+#define turnOffPWM(atimer)                                   \
+  ( (atimer) == NOT_ON_TIMER                                 \
+  ? (void)0                                                  \
+  : (void)hwtimer_pwm_disable                                \
+      (atimer >> HW_TIMER_SHIFT, atimer & HWT_CHANNEL_MASK)  \
+  )
+
+/*
+ * micros on arduino takes timer overflows into account.
+ * We put in the seconds counter. To get a consistent seconds / ticks
+ * value we have to disable interrupts.
+ */
+static inline uint32_t micros (void)
+{
+  uint32_t ticks;
+  uint8_t sreg = SREG;
+  cli ();
+  ticks = clock_seconds () * 1000000L
+        + clock_time () * 1000L / CLOCK_SECOND;
+  SREG = sreg;
+  return ticks;
+}
+/*
+ * millis counts only internal timer ticks since start, not trying to do
+ * something about overflows. Note that we don't try to emulate overflow
+ * behaviour of arduino implementation.
+ */
+#define millis()              (((uint32_t)clock_time())*1000L/CLOCK_SECOND)
+#define micros()              (clock_seconds()*1000L+
+#define delay(ms)             clock_delay_msec(ms)
+#define delayMicroseconds(us) clock_delay_usec(us)
+
+#define analogRead(analogpin) readADC(analogpin)
+
 #ifdef __cplusplus
 } // extern "C"
 #endif
diff --git a/examples/osd/arduino-sketch/led_pwm.h b/examples/osd/arduino-sketch/led_pwm.h
index 6ace57f8d..31356fd78 100644
--- a/examples/osd/arduino-sketch/led_pwm.h
+++ b/examples/osd/arduino-sketch/led_pwm.h
@@ -21,10 +21,15 @@
 #include "erbium.h"
 #include "er-coap-13.h"
 
-extern uint8_t pwm;
-extern uint8_t period_100ms;
+extern uint8_t  pwm;
+extern uint8_t  period_100ms;
+extern uint16_t analog1_voltage;
+extern uint16_t analog5_voltage;
+
 extern resource_t resource_led_pwm;
 extern resource_t resource_led_period;
+extern resource_t resource_analog1_voltage;
+extern resource_t resource_analog5_voltage;
 
 #endif // led_pwm_h
 /** @} */
diff --git a/examples/osd/arduino-sketch/resource_led_pwm.c b/examples/osd/arduino-sketch/resource_led_pwm.c
index 1cca70bf1..2ed1cdd78 100644
--- a/examples/osd/arduino-sketch/resource_led_pwm.c
+++ b/examples/osd/arduino-sketch/resource_led_pwm.c
@@ -69,6 +69,38 @@ GENERIC_RESOURCE \
     , period_to_string
     );
 
+size_t
+analog1_v (const char *name, uint8_t is_json, char *buf, size_t bufsize)
+{
+  return snprintf
+    (buf, bufsize, "%d.%03d", analog1_voltage / 1000, analog1_voltage % 1000);
+}
+
+GENERIC_RESOURCE \
+    ( analog1_voltage, METHOD_GET
+    , "analog/1"
+    , Analog 1 voltage
+    , V
+    , NULL
+    , analog1_v
+    );
+
+size_t
+analog5_v (const char *name, uint8_t is_json, char *buf, size_t bufsize)
+{
+  return snprintf
+    (buf, bufsize, "%d.%03d", analog5_voltage / 1000, analog5_voltage % 1000);
+}
+
+GENERIC_RESOURCE \
+    ( analog5_voltage, METHOD_GET
+    , "analog/5"
+    , Analog 5 voltage
+    , V
+    , NULL
+    , analog5_v
+    );
+
 /*
  * VI settings, see coding style
  * ex:ts=8:et:sw=2
diff --git a/examples/osd/arduino-sketch/sketch.pde b/examples/osd/arduino-sketch/sketch.pde
index 4a1250796..13da7e6bb 100644
--- a/examples/osd/arduino-sketch/sketch.pde
+++ b/examples/osd/arduino-sketch/sketch.pde
@@ -15,8 +15,10 @@ extern "C" {
 #include "led_pwm.h"
 #define LED_PIN 5
 
-uint8_t pwm          = 128;
-uint8_t period_100ms = 10; /* one second */
+uint8_t  pwm             = 128;
+uint8_t  period_100ms    = 10; /* one second */
+uint16_t analog1_voltage = 0;
+uint16_t analog5_voltage = 0;
 }
 
 void setup (void)
@@ -24,12 +26,16 @@ void setup (void)
     rest_init_engine ();
     rest_activate_resource (&resource_led_pwm);
     rest_activate_resource (&resource_led_period);
+    rest_activate_resource (&resource_analog1_voltage);
+    rest_activate_resource (&resource_analog5_voltage);
 }
 
 void loop (void)
 {
     /* Use 255 - pwm, LED on merkur-board is wired to +3.3V */
     analogWrite (LED_PIN, 255 - pwm);
+    analog1_voltage = analogRead (1) * 1600L / 1023L;
+    analog5_voltage = analogRead (5) * 1600L / 1023L;
     printf ("clock : %u\nmillis: %lu\n", clock_time (), millis ());
     delay (period_100ms * 100);
     analogWrite (LED_PIN, 255); /* OFF: LED on merkur-board is wired to +3.3V */
diff --git a/platform/osd-merkur/Makefile.osd-merkur b/platform/osd-merkur/Makefile.osd-merkur
index 9650a201b..3fb160bdd 100644
--- a/platform/osd-merkur/Makefile.osd-merkur
+++ b/platform/osd-merkur/Makefile.osd-merkur
@@ -27,7 +27,7 @@ CONTIKI_TARGET_SOURCEFILES += servo.c servo-sensor.c
 #Needed for Relay 1 to 4
 CONTIKI_TARGET_SOURCEFILES += relay.c relay-sensor.c
 # Arduino
-CONTIKI_TARGET_SOURCEFILES += wiring_digital.c wiring_analog.c
+CONTIKI_TARGET_SOURCEFILES += wiring_digital.c
 
 CONTIKIBOARD=.
 BOOTLOADER_START = 0x1F000
diff --git a/platform/osd-merkur/dev/Arduino.h b/platform/osd-merkur/dev/Arduino.h
index 4d9208864..e0ea47b10 100644
--- a/platform/osd-merkur/dev/Arduino.h
+++ b/platform/osd-merkur/dev/Arduino.h
@@ -42,15 +42,8 @@ extern "C"{
 #define FALLING 2
 #define RISING 3
 
-#if defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__)
-#define INTERNAL1V1 2
-#define INTERNAL2V56 3
-#elif defined(__AVR_ATmega128RFA1__)
-#else
-#define INTERNAL 3
-#endif
-#define DEFAULT 1
-#define EXTERNAL 0
+#define DEFAULT  ADC_DEFAULT
+#define EXTERNAL ADC_EXTERNAL
 
 // undefine stdlib's abs if encountered
 #ifdef abs
@@ -85,18 +78,9 @@ typedef unsigned int word;
 typedef uint8_t boolean;
 typedef uint8_t byte;
 
-/*
- * This has been renamed from init to arduino_init, the original
- * function name is way too generic. The arduino compatibility framework
- * makes sure the correct function is called.
- */
-void arduino_init(void);
-
 void pinMode(uint8_t, uint8_t);
 void digitalWrite(uint8_t, uint8_t);
 int digitalRead(uint8_t);
-int analogRead(uint8_t);
-void analogReference(uint8_t mode);
 
 unsigned long pulseIn(uint8_t pin, uint8_t state, unsigned long timeout);
 
diff --git a/platform/osd-merkur/dev/adc.c b/platform/osd-merkur/dev/adc.c
index 82c66411f..7efde72e1 100644
--- a/platform/osd-merkur/dev/adc.c
+++ b/platform/osd-merkur/dev/adc.c
@@ -36,33 +36,28 @@
 * Paulo Louro <paulolouro@binarylabs.dk>
 */
 
-#include <avr/io.h>
+#include "adc.h"
 
-#ifndef cbi
-#define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))
-#endif
-#ifndef sbi
-#define sbi(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit))
-#endif
+static uint8_t analog_reference = ADC_DEFAULT;
+
+/*
+ * For arduino interface for setting external reference voltage
+ * Note that applying an external voltage *and* then setting the analog
+ * reference to something internal will short the internal and the
+ * external reference voltage and most likely destroy the processor.
+ */
+void analogReference(uint8_t mode)
+{
+    analog_reference = mode;
+}
 
 int readADC(uint8_t pin)
 {
   int result = 0;
 
-  if ( pin >= 14 )
-    pin -= 14;
-
-  ADMUX = _BV(REFS1) | _BV(REFS0) | ( pin & 7 ) ;
-  ADCSRA = _BV(ADEN) | _BV(ADPS0) | _BV(ADPS2) ;
-  sbi(ADCSRA,ADSC);
-  loop_until_bit_is_clear(ADCSRA,ADSC);
-
-
-  result = ADC;
-  
-  ADCSRA=0; //disable ADC
-  ADMUX=0; //turn off internal vref
-
+  adc_setup (analog_reference, pin);
+  result = adc_read ();
+  adc_fin ();
   return result;
 }
 
@@ -77,13 +72,13 @@ int readInternalTemp(void)
   ADMUX = _BV(REFS1) | _BV(REFS0) | 0b1001 ;
   ADCSRA = _BV(ADEN) | _BV(ADPS0) | _BV(ADPS2) ;
 
-  sbi(ADCSRA,ADSC);
+  ADCSRA |= 1 << ADSC;
   loop_until_bit_is_clear(ADCSRA,ADSC);
   reading = ADC;
 
+  ADCSRB=0; //disable ADC, need to write B first for MUX5 bit
   ADCSRA=0; //disable ADC
-  ADCSRB=0; //disable ADC
   ADMUX=0; //turn off internal vref
 
   return reading * 113 - 27280;
-}
\ No newline at end of file
+}
diff --git a/platform/osd-merkur/dev/adc.h b/platform/osd-merkur/dev/adc.h
index ea851f237..6ea4cf0ab 100644
--- a/platform/osd-merkur/dev/adc.h
+++ b/platform/osd-merkur/dev/adc.h
@@ -1,8 +1,52 @@
 #ifndef __ADC_ARCH_H__
 #define __ADC_ARCH_H__
 
+#include <avr/io.h>
+
+/*
+ * Reference voltage
+ * The default is 1.6V reference voltage
+ * The selected reference voltage is the maximum voltage that can be
+ * measured.
+ * Directly provide shifted variants so we don't need to shift.
+ */
+#define ADC_1_5      (2<<6)
+#define ADC_1_6      (3<<6)
+#define ADC_1_8      (1<<6)
+#define ADC_EXTERNAL (0<<6)
+#define ADC_DEFAULT  ADC_1_6
+
+/* sometimes it's desirable to decouple setup / finish from sampling */
+
+static inline void adc_setup (uint8_t ref_volt, uint8_t pin)
+{
+  ADMUX = ref_volt | (pin & 0x7);
+  ADCSRA = _BV(ADEN) | _BV(ADPS0) | _BV(ADPS2);
+}
+
+static inline int adc_read (void)
+{
+  ADCSRA |= (1 << ADSC);
+  loop_until_bit_is_clear (ADCSRA, ADSC);
+  return ADC;
+}
+
+static inline void adc_fin (void)
+{
+    ADCSRA = 0;
+    ADMUX  = 0;
+}
+  
+static inline void adc_init (void)
+{
+    ADCSRC = 0;
+    ADCSRB = 0;
+    adc_fin ();
+}
+
 int readADC(uint8_t pin);
 long readVcc();
 int readInternalTemp(void);
+void analogReference(uint8_t mode);
 
-#endif /* __ADC_ARCH_H__ */
\ No newline at end of file
+#endif /* __ADC_ARCH_H__ */
diff --git a/platform/osd-merkur/dev/hw-arduino.h b/platform/osd-merkur/dev/hw-arduino.h
index f59f8daf2..1894d23cc 100644
--- a/platform/osd-merkur/dev/hw-arduino.h
+++ b/platform/osd-merkur/dev/hw-arduino.h
@@ -71,32 +71,6 @@ extern "C"{
 #define arduino_pwm_timer_init() \
   (hwtimer_ini (3, HWT_WGM_PWM_PHASE_8_BIT, HWT_CLOCK_PRESCALER_64, 0))
 
-/*
- * micros on arduino takes timer overflows into account.
- * We put in the seconds counter. To get a consistent seconds / ticks
- * value we have to disable interrupts.
- */
-static inline uint32_t micros (void)
-{
-  uint32_t ticks;
-  uint8_t sreg = SREG;
-  cli ();
-  ticks = clock_seconds () * 1000000L
-        + clock_time () * 1000L / CLOCK_SECOND;
-  SREG = sreg;
-  return ticks;
-}
-/*
- * millis counts only internal timer ticks since start, not trying to do
- * something about overflows. Note that we don't try to emulate overflow
- * behaviour of arduino implementation.
- */
-#define millis()              (((uint32_t)clock_time())*1000L/CLOCK_SECOND)
-#define micros()              (clock_seconds()*1000L+
-#define delay(ms)             clock_delay_msec(ms)
-#define delayMicroseconds(us) clock_delay_usec(us)
-
-
 /*
  * VI settings, see coding style
  * ex:ts=8:et:sw=2
diff --git a/platform/osd-merkur/dev/wiring_analog.c b/platform/osd-merkur/dev/wiring_analog.c
deleted file mode 100644
index 630e95721..000000000
--- a/platform/osd-merkur/dev/wiring_analog.c
+++ /dev/null
@@ -1,48 +0,0 @@
-/*
-  wiring_analog.c - analog input and output
-  Part of Arduino - http://www.arduino.cc/
-
-  Copyright (c) 2005-2006 David A. Mellis
-
-  This library is free software; you can redistribute it and/or
-  modify it under the terms of the GNU Lesser General Public
-  License as published by the Free Software Foundation; either
-  version 2.1 of the License, or (at your option) any later version.
-
-  This library is distributed in the hope that it will be useful,
-  but WITHOUT ANY WARRANTY; without even the implied warranty of
-  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-  Lesser General Public License for more details.
-
-  You should have received a copy of the GNU Lesser General
-  Public License along with this library; if not, write to the
-  Free Software Foundation, Inc., 59 Temple Place, Suite 330,
-  Boston, MA  02111-1307  USA
-
-  Modified 28 September 2010 by Mark Sproul
-
-  $Id: wiring.c 248 2007-02-03 15:36:30Z mellis $
-*/
-
-#include "wiring_private.h"
-#include "pins_arduino.h"
-#include "adc.h"
-
-uint8_t analog_reference = DEFAULT;
-
-void analogReference(uint8_t mode)
-{
-	// can't actually set the register here because the default setting
-	// will connect AVCC and the AREF pin, which would cause a short if
-	// there's something connected to AREF.
-	analog_reference = mode;
-}
-
-int analogRead(uint8_t pin)
-{
-	return readADC(pin);
-}
-
-/*
- * analogWrite is now implemented in dev/arduino/arduino-compat.h
- */
diff --git a/platform/osd-merkur/dev/wiring_digital.c b/platform/osd-merkur/dev/wiring_digital.c
index cac0a7b12..75b6745d6 100644
--- a/platform/osd-merkur/dev/wiring_digital.c
+++ b/platform/osd-merkur/dev/wiring_digital.c
@@ -60,83 +60,6 @@ void pinMode(uint8_t pin, uint8_t mode)
 	}
 }
 
-// Forcing this inline keeps the callers from having to push their own stuff
-// on the stack. It is a good performance win and only takes 1 more byte per
-// user than calling. (It will take more bytes on the 168.)
-//
-// But shouldn't this be moved into pinMode? Seems silly to check and do on
-// each digitalread or write.
-//
-// Mark Sproul:
-// - Removed inline. Save 170 bytes on atmega1280
-// - changed to a switch statment; added 32 bytes but much easier to read and maintain.
-// - Added more #ifdefs, now compiles for atmega645
-//
-//static inline void turnOffPWM(uint8_t timer) __attribute__ ((always_inline));
-//static inline void turnOffPWM(uint8_t timer)
-static void turnOffPWM(uint8_t timer)
-{
-	switch (timer)
-	{
-		#if defined(TCCR1A) && defined(COM1A1)
-		case TIMER1A:   cbi(TCCR1A, COM1A1);    break;
-		#endif
-		#if defined(TCCR1A) && defined(COM1B1)
-		case TIMER1B:   cbi(TCCR1A, COM1B1);    break;
-		#endif
-		#if defined(TCCR1A) && defined(COM1B1)
-		case TIMER1C:   cbi(TCCR1A, COM1C1);    break;
-		#endif
-		
-		#if defined(TCCR2) && defined(COM21)
-		case  TIMER2:   cbi(TCCR2, COM21);      break;
-		#endif
-		
-		#if defined(TCCR0A) && defined(COM0A1)
-		case  TIMER0A:  cbi(TCCR0A, COM0A1);    break;
-		#endif
-		
-		#if defined(TIMER0B) && defined(COM0B1)
-		case  TIMER0B:  cbi(TCCR0A, COM0B1);    break;
-		#endif
-		#if defined(TCCR2A) && defined(COM2A1)
-		case  TIMER2A:  cbi(TCCR2A, COM2A1);    break;
-		#endif
-		#if defined(TCCR2A) && defined(COM2B1)
-		case  TIMER2B:  cbi(TCCR2A, COM2B1);    break;
-		#endif
-		
-		#if defined(TCCR3A) && defined(COM3A1)
-		case  TIMER3A:  cbi(TCCR3A, COM3A1);    break;
-		#endif
-		#if defined(TCCR3A) && defined(COM3B1)
-		case  TIMER3B:  cbi(TCCR3A, COM3B1);    break;
-		#endif
-		#if defined(TCCR3A) && defined(COM3C1)
-		case  TIMER3C:  cbi(TCCR3A, COM3C1);    break;
-		#endif
-
-		#if defined(TCCR4A) && defined(COM4A1)
-		case  TIMER4A:  cbi(TCCR4A, COM4A1);    break;
-		#endif					
-		#if defined(TCCR4A) && defined(COM4B1)
-		case  TIMER4B:  cbi(TCCR4A, COM4B1);    break;
-		#endif
-		#if defined(TCCR4A) && defined(COM4C1)
-		case  TIMER4C:  cbi(TCCR4A, COM4C1);    break;
-		#endif			
-		#if defined(TCCR4C) && defined(COM4D1)
-		case TIMER4D:	cbi(TCCR4C, COM4D1);	break;
-		#endif			
-			
-		#if defined(TCCR5A)
-		case  TIMER5A:  cbi(TCCR5A, COM5A1);    break;
-		case  TIMER5B:  cbi(TCCR5A, COM5B1);    break;
-		case  TIMER5C:  cbi(TCCR5A, COM5C1);    break;
-		#endif
-	}
-}
-
 void digitalWrite(uint8_t pin, uint8_t val)
 {
 	uint8_t timer = digitalPinToTimer(pin);