diff --git a/miosix/arch/cortexM3_efm32gg/common/interfaces-impl/fixme_dma.h b/miosix/arch/cortexM3_efm32gg/common/interfaces-impl/fixme_dma.h
index 87587c1c1793b29ae425429ea9703eb4fef12bda..95c9b4444fb6554d2ba1b2b9133506d135380b8e 100644
--- a/miosix/arch/cortexM3_efm32gg/common/interfaces-impl/fixme_dma.h
+++ b/miosix/arch/cortexM3_efm32gg/common/interfaces-impl/fixme_dma.h
@@ -2,9 +2,10 @@
  *  FIXXX ME
  ***************************************************************************/
 
-#ifndef PORTABILITY_H
-#define	PORTABILITY_H
+#ifndef PORTABILITY_FIXME_H
+#define	PORTABILITY_FIXME_H
 
+namespace miosix_private{
 
 #define DMA_CHANNEL_ADC                   0
 
@@ -118,6 +119,6 @@ void waitRtc(int val);
 void initRtc(); 
 void IRQdeepSleep();
     
-
+}
 
 #endif
diff --git a/miosix/arch/cortexM3_efm32gg/common/interfaces-impl/portability.cpp b/miosix/arch/cortexM3_efm32gg/common/interfaces-impl/portability.cpp
index 4efe0740e13a45a713396b54c93af1d9957eaf6c..6b542995ddd72fad16454742ad9c3daaf998cfcf 100644
--- a/miosix/arch/cortexM3_efm32gg/common/interfaces-impl/portability.cpp
+++ b/miosix/arch/cortexM3_efm32gg/common/interfaces-impl/portability.cpp
@@ -33,6 +33,7 @@
 #include "kernel/scheduler/scheduler.h"
 #include "kernel/scheduler/timer_interrupt.h"
 #include <algorithm>
+#include "fixme_dma.h"
 
 #define ADCSAMPLES                        1024
 
diff --git a/miosix/config/arch/cortexM3_efm32gg/efm32gg332f1024_wandstem/board_settings.h b/miosix/config/arch/cortexM3_efm32gg/efm32gg332f1024_wandstem/board_settings.h
index 20cb611b17e6224f987dff6f40c49b3672aed731..44ff125323730759df27d59076e20949e5b6e7d2 100644
--- a/miosix/config/arch/cortexM3_efm32gg/efm32gg332f1024_wandstem/board_settings.h
+++ b/miosix/config/arch/cortexM3_efm32gg/efm32gg332f1024_wandstem/board_settings.h
@@ -53,6 +53,9 @@ namespace miosix {
 /// Size of stack for main().
 const unsigned int MAIN_STACK_SIZE=4096;
 
+const unsigned int preemptionPeriodNs=1000000;
+
+
 /// Frequency of tick (in Hz). The frequency of the efm32gg332f1024 timer in
 /// the board can be divided by 1000. This allows to use a 1KHz tick and
 /// the minimun Thread::sleep value is 1ms