diff --git a/sw/airborne/main_logger.c b/sw/airborne/main_logger.c
index fa2db2dfde..26544efca6 100644
--- a/sw/airborne/main_logger.c
+++ b/sw/airborne/main_logger.c
@@ -1,5 +1,5 @@
 /*
- * $Id: main_logger.c 3080 2009-03-11 17:02:19Z gautier $
+ * $Id$
  *  
  * Copyright (C) 2009  Martin Mueller
  *
@@ -29,6 +29,54 @@
  * to a (micro) SD card through the efsl library
  */
 
+  /* XBee-message: ABCDxxxxxxxE
+     A XBEE_START (0x7E)
+     B LENGTH_MSB (D->D)
+     C LENGTH_LSB
+     D XBEE_PAYLOAD
+       0 XBEE_TX16 (0x01) / XBEE_RX16 (0x81)
+       1 FRAME_ID (0)     / SRC_ID_MSB
+       2 DEST_ID_MSB      / SRC_ID_LSB
+       3 DEST_ID_LSB      / XBEE_RSSI
+       4 TX16_OPTIONS (0) / RX16_OPTIONS
+       5 PPRZ_DATA
+         0 SENDER_ID
+         1 MSG_ID
+         2 MSG_PAYLOAD
+         . DATA (messages.xml)
+     E XBEE_CHECKSUM (sum[A->D])
+     
+    ID is AC_ID for aircraft, 0x100 for ground station
+  */
+
+  /* PPRZ-message: ABCxxxxxxxDE
+     A PPRZ_STX (0x99)
+     B LENGTH (A->E)
+     C PPRZ_DATA
+       0 SENDER_ID
+       1 MSG_ID
+       2 MSG_PAYLOAD
+       . DATA (messages.xml)
+     D PPRZ_CHECKSUM_A (sum[B->C])
+     E PPRZ_CHECKSUM_B (sum[ck_a])
+  */
+
+  /* LOG-message: ABCDEFGHxxxxxxxI
+     A PPRZ_STX (0x99)
+     B LENGTH (H->H)
+     C SOURCE (0=uart0, 1=uart1, 2=i2c0, ...)
+     D TIMESTAMP_LSB (100 microsec raster)
+     E TIMESTAMP
+     F TIMESTAMP
+     G TIMESTAMP_MSB
+     H PPRZ_DATA
+       0 SENDER_ID
+       1 MSG_ID
+       2 MSG_PAYLOAD
+       . DATA (messages.xml)
+     I CHECKSUM (sum[B->H])
+  */
+
 #include "std.h"
 #include "init_hw.h"
 #include "sys_time.h"
@@ -51,10 +99,51 @@
 /* BUTTON that stops logging (BUTTON = P0.7, INT1 = P0.14) */
 #define STOP_KEY 14
 
+/** Constants for the API protocol */
+#define XBEE_START 0x7e
+#define XBEE_TX16_ID 0x01
+#define TX16_OPTIONS 0x00
+#define NO_FRAME_ID 0
+#define XBEE_RFDATA_OFFSET 5
+#define XBEE_RX16_ID 0x81
+
+/** Status of the API packet receiver automata */
+#define XBEE_UNINIT 0
+#define XBEE_GOT_START 1
+#define XBEE_GOT_LENGTH_MSB 2
+#define XBEE_GOT_LENGTH_LSB 3
+#define XBEE_GOT_PAYLOAD 4
+#define XBEE_PAYLOAD_LEN 256
+
+/** Receiving pprz messages */
+#define STX  0x99
+#define UNINIT 0
+#define GOT_STX 1
+#define GOT_LENGTH 2
+#define GOT_PAYLOAD 3
+#define GOT_CRC1 4
+#define PPRZ_PAYLOAD_LEN 256
+#define PPRZ_DATA_OFFSET 2
+
+/** logging messages **/
+#define LOG_DATA_OFFSET 7
+#define MSG_SIZE 256
+/* logging frequency in Hz */
+#define LOG_FREQ 10000
+/* T0_CLK = PCLK / T0_PCLK_DIV (shall be 15MHz)
+   frequency = T0_CLK / LOG_FREQ (10kHz = 100micro seconds) */
+#define LOG_DIV ((PCLK / T0_PCLK_DIV) / LOG_FREQ)
+
 static inline void main_init( void );
 static inline void main_periodic_task( void );
 int main_log(void);
+
 void set_filename(unsigned int local, char* name);
+unsigned char checksum(unsigned char start, unsigned char* data, int length);
+unsigned int getclock(void);
+void log_payload(int len, unsigned char source, unsigned int timestamp);
+void log_xbee(unsigned char c);
+void log_pprz(unsigned char c);
 
 extern int main_mass_storage(void);
 
@@ -63,6 +152,21 @@ EmbeddedFileSystem efs;
 EmbeddedFile filer;	
 EmbeddedFile filew;
 
+unsigned char xbeel_payload[XBEE_PAYLOAD_LEN];
+unsigned char pprzl_payload[PPRZ_PAYLOAD_LEN];
+volatile unsigned char xbeel_payload_len;
+volatile unsigned char pprzl_payload_len;
+unsigned char xbeel_error;
+unsigned char pprzl_error;
+unsigned char log_buffer[MSG_SIZE]  __attribute__ ((aligned));
+static unsigned int xbeel_timestamp = 0;
+static unsigned int pprzl_timestamp = 0;
+unsigned int nb_messages = 0;
+unsigned int nb_fail_write = 0;
+int bytes = 0;
+unsigned int clock_msb = 0;
+unsigned int clock_lsb_last = 0;
+
 void set_filename(unsigned int local, char* name)
 {
     /* do not use sprintf or similar */
@@ -75,6 +179,167 @@ void set_filename(unsigned int local, char* name)
     name[8]='.';name[9]='t';name[10]='x';name[11]='t';name[12]=0;
 }
 
+unsigned char checksum(unsigned char start, unsigned char* data, int length)
+{
+    int i;
+    unsigned char retval = start;
+    for (i=0;i<length;i++) retval += data[i];
+
+    return retval;
+}
+
+unsigned int getclock(void)
+{
+    uint64_t clock;
+    uint32_t clock_lsb;
+
+    clock_lsb = T0TC;
+
+    if (clock_lsb < clock_lsb_last) clock_msb++;
+    clock_lsb_last = clock_lsb;
+
+    clock = (((uint64_t)clock_msb << 32) | (uint64_t)clock_lsb) / LOG_DIV;
+
+    return(clock & 0xFFFFFFFF);
+}
+
+/** Parsing a frame data and copy the payload to the log buffer */
+void log_payload(int len, unsigned char source, unsigned int timestamp)
+{
+  unsigned char chk;
+  
+  /* start delimiter */
+  log_buffer[0] = STX;
+
+  /* length is just payload */
+  log_buffer[1] = len & 0xFF;
+
+  /* source */
+  log_buffer[2] = source;
+    
+  /* add a 32bit timestamp */
+  log_buffer[3] = (timestamp) & 0xFF;       // LSB first
+  log_buffer[4] = (timestamp >> 8)  & 0xFF;
+  log_buffer[5] = (timestamp >> 16) & 0xFF;
+  log_buffer[6] = (timestamp >> 24) & 0xFF;
+
+  /* data is already written */
+
+  /* calculate checksum over start+length+timestamp+data */
+  log_buffer[LOG_DATA_OFFSET+len] = checksum(0, &log_buffer[1], LOG_DATA_OFFSET+len-1);
+
+  /* write data, start+length+timestamp+data+checksum */
+  chk = file_write(&filew, LOG_DATA_OFFSET+len+1, log_buffer);
+
+  if (len != chk) 
+  {
+    nb_fail_write++;
+  }
+  
+  bytes += chk;
+  nb_messages++;
+//  dl_parse_msg();
+}
+
+/** Parsing a XBee API frame */
+void log_xbee(unsigned char c)
+{
+  static unsigned char xbeel_status = XBEE_UNINIT;
+  static unsigned char cs, payload_idx, i;
+
+  switch (xbeel_status) {
+  case XBEE_UNINIT:
+    if (c == XBEE_START)
+    {
+      xbeel_timestamp = getclock();
+      xbeel_status++;
+    }
+    break;
+  case XBEE_GOT_START:
+    xbeel_payload_len = c<<8;
+    xbeel_status++;
+    break;
+  case XBEE_GOT_LENGTH_MSB:
+    xbeel_payload_len |= c;
+    xbeel_status++;
+    payload_idx = 0;
+    cs=0;
+    break;
+  case XBEE_GOT_LENGTH_LSB:
+    xbeel_payload[payload_idx] = c;
+    cs += c;
+    payload_idx++;
+    if (payload_idx == xbeel_payload_len)
+      xbeel_status++;
+    break;
+  case XBEE_GOT_PAYLOAD:
+    if (c + cs != 0xff)
+      goto error;
+    if ((xbeel_payload[0] != XBEE_RX16_ID) &&
+        (xbeel_payload[0] != XBEE_TX16_ID))
+      goto error;
+    /* copy the XBee message to the logger buffer */
+    for (i = 0; i < xbeel_payload_len-XBEE_RFDATA_OFFSET; i++) {
+      log_buffer[i+LOG_DATA_OFFSET] = xbeel_payload[i+XBEE_RFDATA_OFFSET];
+    }
+    log_payload(xbeel_payload_len-XBEE_RFDATA_OFFSET, 0, xbeel_timestamp);
+    goto restart;
+  }
+  return;
+ error:
+  xbeel_error++;
+ restart:
+  xbeel_status = XBEE_UNINIT;
+  return;
+}
+
+void log_pprz(unsigned char c)
+{
+  static unsigned char pprzl_status = UNINIT;
+  static unsigned char _ck_a, _ck_b, payload_idx, i;
+
+  switch (pprzl_status) {
+  case UNINIT:
+    if (c == STX)
+      pprzl_timestamp = getclock();
+      pprzl_status++;
+    break;
+  case GOT_STX:
+    pprzl_payload_len = c-4; /* Counting STX, LENGTH and CRC1 and CRC2 */
+    _ck_a = _ck_b = c;
+    pprzl_status++;
+    payload_idx = 0;
+    break;
+  case GOT_LENGTH:
+    pprzl_payload[payload_idx] = c;
+    _ck_a += c; _ck_b += _ck_a;
+    payload_idx++;
+    if (payload_idx == pprzl_payload_len)
+      pprzl_status++;
+    break;
+  case GOT_PAYLOAD:
+    if (c != _ck_a)
+      goto error;
+    pprzl_status++;
+    break;
+  case GOT_CRC1:
+    if (c != _ck_b)
+      goto error;
+    /* copy the pprz message to the logger buffer */
+    for (i = 0; i < pprzl_payload_len; i++) {
+      log_buffer[i+LOG_DATA_OFFSET] = pprzl_payload[i];
+    }
+    log_payload(pprzl_payload_len, 0, pprzl_timestamp);
+    goto restart;
+  }
+  return;
+ error:
+  pprzl_error++;
+ restart:
+  pprzl_status = UNINIT;
+  return;
+}
+
 int main_log(void)
 {
     unsigned int count;
@@ -106,7 +371,9 @@ int main_log(void)
         {   
 			LED_TOGGLE(2);
 			inc = Uart1Getch();
-			file_write(&filew, 1, &inc);
+            log_pprz(inc);
+//            log_xbee(inc);
+//            file_write(&filew, 1, &inc);
         }
     }
     LED_OFF(2);
@@ -145,3 +412,4 @@ static inline void main_init( void ) {
 static inline void main_periodic_task( void ) {
   LED_TOGGLE(1);
 }
+