diff --git a/sam3s_example/simtrace/simtrace.h b/sam3s_example/simtrace/simtrace.h
index 0e024e9f..ff29fe2d 100644
--- a/sam3s_example/simtrace/simtrace.h
+++ b/sam3s_example/simtrace/simtrace.h
@@ -1,6 +1,10 @@
 #ifndef SIMTRACE_H
 #define SIMTRACE_H
 
+enum confNum {
+    CFG_NUM_SNIFF = 1, CFG_NUM_PHONE, CFG_NUM_MITM, NUM_CONF
+};
+
 // FIXME: static function definitions
 extern uint32_t _ISO7816_GetChar( uint8_t *pCharToReceive );
 extern uint32_t _ISO7816_SendChar( uint8_t CharToSend );
diff --git a/sam3s_example/simtrace/simtrace_main.c b/sam3s_example/simtrace/simtrace_main.c
index 1a170059..dbc74e53 100644
--- a/sam3s_example/simtrace/simtrace_main.c
+++ b/sam3s_example/simtrace/simtrace_main.c
@@ -5,20 +5,10 @@
 
 #include "board.h"
 
-/*------------------------------------------------------------------------------
- *         Internal definitions
- *------------------------------------------------------------------------------*/
-#define CONF_NONE           0
-#define CONF_SNIFFER        1
-#define CONF_CCID_READER    2
-#define CONF_SIMCARD_EMUL   3
-#define CONF_MITM           4
-
-
 /*------------------------------------------------------------------------------
  *         Internal variables
  *------------------------------------------------------------------------------*/
-uint8_t simtrace_config = CONF_NONE;
+uint8_t simtrace_config = 0;
 uint8_t conf_changed = 1;
 
 uint8_t rcvdChar = 0;
@@ -69,9 +59,10 @@ extern int main( void )
 /*  FIXME: Or should we move the while loop into every case, and break out
     in case the config changes? */
         switch(simtrace_config) {
-            case CONF_SNIFFER:
+            case CFG_NUM_SNIFF:
                 if (conf_changed) {
                     Sniffer_Init();
+                    printf("****+ Changed to CFG_NUM_SNIFF\n\r");
                     conf_changed = 0;
                 } else {
                     if (rcvdChar != 0) {
@@ -80,17 +71,18 @@ extern int main( void )
                     }
                 }
                 break;
-            case CONF_CCID_READER:
+/*            case CONF_CCID_READER:
                 if (conf_changed) {
                     // Init
                     conf_changed = 0;
                 } else {
                     // Receive char
                 }
-                break;
-            case CONF_SIMCARD_EMUL:
+                break;  */
+            case CFG_NUM_PHONE:
                 if (conf_changed) {
                     Phone_Master_Init();
+                    printf("****+ Changed to CFG_NUM_PHONE\n\r");
                     conf_changed = 0;
                     /*  Configure ISO7816 driver */
                     // FIXME:    PIO_Configure(pPwr, PIO_LISTSIZE( pPwr ));
@@ -100,8 +92,9 @@ extern int main( void )
                     // ISO7816_SendChar(char_to_send);
                 }
                 break;
-            case CONF_MITM:
+            case CFG_NUM_MITM:
                 if (conf_changed) {
+                    printf("****+ Changed to CFG_NUM_MITM\n\r");
                     // Init
                     conf_changed = 0;
                 } else {
diff --git a/sam3s_example/simtrace/usb.c b/sam3s_example/simtrace/usb.c
index c2cdda2c..8edaf557 100644
--- a/sam3s_example/simtrace/usb.c
+++ b/sam3s_example/simtrace/usb.c
@@ -171,7 +171,7 @@ const SIMTraceDriverConfigurationDescriptorSniffer configurationDescriptorSniffe
         USBGenericDescriptor_CONFIGURATION,
         sizeof(SIMTraceDriverConfigurationDescriptorSniffer),
         1, /* There is one interface in this configuration */
-        1, /* This is configuration #1 */
+        CFG_NUM_SNIFF, /* configuration number */
         SNIFFER_CONF_STR, /* string descriptor for this configuration */
         USBD_BMATTRIBUTES,
         USBConfigurationDescriptor_POWER(100)
@@ -243,7 +243,7 @@ const SIMTraceDriverConfigurationDescriptorPhone configurationDescriptorPhone =
         USBGenericDescriptor_CONFIGURATION,
         sizeof(SIMTraceDriverConfigurationDescriptorSniffer),
         1, /* There is one interface in this configuration */
-        2, /* This is configuration #2 */
+        CFG_NUM_PHONE, /* configuration number */
         PHONE_CONF_STR, /* string descriptor for this configuration */
         USBD_BMATTRIBUTES,
         USBConfigurationDescriptor_POWER(100)
@@ -305,7 +305,7 @@ const SIMTraceDriverConfigurationDescriptorMITM configurationDescriptorMITM = {
         USBGenericDescriptor_CONFIGURATION,
         sizeof(SIMTraceDriverConfigurationDescriptorMITM),
         2, /* There are two interfaces in this configuration */
-        3, /* This is configuration #3 */
+        CFG_NUM_MITM, /* configuration number */
         MITM_CONF_STR, /* string descriptor for this configuration */
         USBD_BMATTRIBUTES,
         USBConfigurationDescriptor_POWER(100)