diff --git a/conf/firmwares/subsystems/fixedwing/autopilot.makefile b/conf/firmwares/subsystems/fixedwing/autopilot.makefile
index 5af5506c4e0..6dfc581ea88 100644
--- a/conf/firmwares/subsystems/fixedwing/autopilot.makefile
+++ b/conf/firmwares/subsystems/fixedwing/autopilot.makefile
@@ -183,8 +183,8 @@ sim.srcs 		+= $(fbw_srcs) $(ap_srcs)
 sim.CFLAGS 		+= -DSITL
 sim.srcs 		+= $(SRC_ARCH)/sim_ap.c
 
-sim.CFLAGS 		+= -DDOWNLINK -DPERIODIC_TELEMETRY -DDOWNLINK_TRANSPORT=IvyTransport
-sim.srcs 		+= subsystems/datalink/downlink.c $(SRC_FIRMWARE)/datalink.c $(SRC_ARCH)/ivy_transport.c
+sim.CFLAGS 		+= -DDOWNLINK -DPERIODIC_TELEMETRY -DDOWNLINK_TRANSPORT=ivy_tp -DDOWNLINK_DEVICE=ivy_tp
+sim.srcs 		+= subsystems/datalink/downlink.c $(SRC_FIRMWARE)/datalink.c subsystems/datalink/ivy_transport.c
 
 sim.srcs 		+= $(SRC_ARCH)/sim_gps.c $(SRC_ARCH)/sim_adc_generic.c
 
@@ -223,8 +223,8 @@ jsbsim.srcs 		+= $(SIMDIR)/sim_ac_jsbsim.c $(SIMDIR)/sim_ac_fw.c $(SIMDIR)/sim_a
 jsbsim.CFLAGS 		+= -I/usr/include $(shell pkg-config glib-2.0 --cflags)
 jsbsim.LDFLAGS		+= $(shell pkg-config glib-2.0 --libs) -lglibivy -lm $(shell pcre-config --libs)
 
-jsbsim.CFLAGS 		+= -DDOWNLINK -DPERIODIC_TELEMETRY -DDOWNLINK_TRANSPORT=IvyTransport
-jsbsim.srcs 		+= subsystems/datalink/downlink.c $(SRC_FIRMWARE)/datalink.c $(SRC_ARCH)/ivy_transport.c
+jsbsim.CFLAGS 		+= -DDOWNLINK -DPERIODIC_TELEMETRY -DDOWNLINK_TRANSPORT=ivy_tp -DDOWNLINK_DEVICE=ivy_tp
+jsbsim.srcs 		+= subsystems/datalink/downlink.c $(SRC_FIRMWARE)/datalink.c subsystems/datalink/ivy_transport.c
 
 jsbsim.srcs 		+= $(SRC_ARCH)/jsbsim_hw.c $(SRC_ARCH)/jsbsim_ir.c $(SRC_ARCH)/jsbsim_gps.c $(SRC_ARCH)/jsbsim_ahrs.c $(SRC_ARCH)/jsbsim_transport.c
 
diff --git a/conf/firmwares/subsystems/fixedwing/fdm_crrcsim.makefile b/conf/firmwares/subsystems/fixedwing/fdm_crrcsim.makefile
index a529ca47781..a88d8a1bde3 100644
--- a/conf/firmwares/subsystems/fixedwing/fdm_crrcsim.makefile
+++ b/conf/firmwares/subsystems/fixedwing/fdm_crrcsim.makefile
@@ -47,6 +47,6 @@ nps.srcs += $(NPSDIR)/nps_main.c                 \
        $(NPSDIR)/nps_flightgear.c                \
 
 
-nps.CFLAGS += -DDOWNLINK -DPERIODIC_TELEMETRY -DDOWNLINK_TRANSPORT=IvyTransport
-nps.srcs   += subsystems/datalink/downlink.c $(SRC_FIRMWARE)/datalink.c $(SRC_ARCH)/ivy_transport.c
+nps.CFLAGS += -DDOWNLINK -DPERIODIC_TELEMETRY -DDOWNLINK_TRANSPORT=ivy_tp -DDOWNLINK_DEVICE=ivy_tp
+nps.srcs   += subsystems/datalink/downlink.c $(SRC_FIRMWARE)/datalink.c subsystems/datalink/ivy_transport.c
 
diff --git a/conf/firmwares/subsystems/fixedwing/fdm_jsbsim.makefile b/conf/firmwares/subsystems/fixedwing/fdm_jsbsim.makefile
index de5b2463b33..184f876c452 100644
--- a/conf/firmwares/subsystems/fixedwing/fdm_jsbsim.makefile
+++ b/conf/firmwares/subsystems/fixedwing/fdm_jsbsim.makefile
@@ -65,6 +65,6 @@ nps.srcs += $(NPSDIR)/nps_main.c                 \
 
 nps.srcs += math/pprz_geodetic_wmm2010.c
 
-nps.CFLAGS += -DDOWNLINK -DPERIODIC_TELEMETRY -DDOWNLINK_TRANSPORT=IvyTransport
-nps.srcs   += subsystems/datalink/downlink.c $(SRC_FIRMWARE)/datalink.c $(SRC_ARCH)/ivy_transport.c
+nps.CFLAGS += -DDOWNLINK -DPERIODIC_TELEMETRY -DDOWNLINK_TRANSPORT=ivy_tp -DDOWNLINK_DEVICE=ivy_tp
+nps.srcs   += subsystems/datalink/downlink.c $(SRC_FIRMWARE)/datalink.c subsystems/datalink/ivy_transport.c
 
diff --git a/conf/firmwares/subsystems/rotorcraft/fdm_jsbsim.makefile b/conf/firmwares/subsystems/rotorcraft/fdm_jsbsim.makefile
index 7ba363fc4e5..e19f469a337 100644
--- a/conf/firmwares/subsystems/rotorcraft/fdm_jsbsim.makefile
+++ b/conf/firmwares/subsystems/rotorcraft/fdm_jsbsim.makefile
@@ -62,8 +62,8 @@ nps.srcs += $(NPSDIR)/nps_main.c                 \
 # for geo mag calculation
 nps.srcs += math/pprz_geodetic_wmm2010.c
 
-nps.CFLAGS += -DDOWNLINK -DPERIODIC_TELEMETRY -DDOWNLINK_TRANSPORT=IvyTransport -DDefaultPeriodic='&telemetry_Main'
-nps.srcs += $(SRC_ARCH)/ivy_transport.c
+nps.CFLAGS += -DDOWNLINK -DPERIODIC_TELEMETRY -DDOWNLINK_TRANSPORT=ivy_tp -DDOWNLINK_DEVICE=ivy_tp -DDefaultPeriodic='&telemetry_Main'
+nps.srcs += subsystems/datalink/ivy_transport.c
 nps.srcs += subsystems/datalink/downlink.c subsystems/datalink/telemetry.c
 nps.srcs += $(SRC_FIRMWARE)/rotorcraft_telemetry.c
 nps.srcs += $(SRC_FIRMWARE)/datalink.c
diff --git a/sw/airborne/arch/sim/ivy_transport.c b/sw/airborne/arch/sim/ivy_transport.c
deleted file mode 100644
index 4d8706dcd37..00000000000
--- a/sw/airborne/arch/sim/ivy_transport.c
+++ /dev/null
@@ -1,3 +0,0 @@
-char ivy_buf[256];
-char *ivy_p = ivy_buf;
-int ivy_dl_enabled = 1;
diff --git a/sw/airborne/arch/sim/ivy_transport.h b/sw/airborne/arch/sim/ivy_transport.h
deleted file mode 100644
index d84ff19234b..00000000000
--- a/sw/airborne/arch/sim/ivy_transport.h
+++ /dev/null
@@ -1,73 +0,0 @@
-#include <stdio.h>
-#include <Ivy/ivy.h>
-
-extern char ivy_buf[];
-extern char* ivy_p;
-extern int ivy_dl_enabled;
-
-#define IvyTransportCheckFreeSpace(_dev,_) TRUE
-
-#define IvyTransportSizeOf(_dev, x) (x)
-
-#define IvyTransportHeader(_dev,len) ivy_p=ivy_buf;
-
-#define IvyTransportTrailer(_dev) { *(--ivy_p) = '\0'; if (ivy_dl_enabled) { IvySendMsg("%s",ivy_buf); } }
-
-#define IvyTransportPutUint8(_dev,x) { ivy_p += sprintf(ivy_p, "%u ", x); }
-#define IvyTransportPutNamedUint8(_dev,_name, _x) { ivy_p += sprintf(ivy_p, "%s ", _name); }
-
-#define Space() ivy_p += sprintf(ivy_p, " ");
-#define Comma() ivy_p += sprintf(ivy_p, ",");
-#define DelimStart() ivy_p += sprintf(ivy_p, "|");
-#define DelimEnd() ivy_p += sprintf(ivy_p, "|");
-
-#define IvyTransportPutcByAddr(_dev,x) ivy_p += sprintf(ivy_p, "%c", *x);
-#define IvyTransportPutCharByAddr(_dev,x) IvyTransportPutcByAddr(_dev,x) Space()
-#define IvyTransportPutUintByAddr(_dev,x) ivy_p += sprintf(ivy_p, "%u", *x);
-#define IvyTransportPutUint8ByAddr(_dev,x) IvyTransportPutUintByAddr(_dev,x) Space()
-#define IvyTransportPutUint16ByAddr(_dev,x) IvyTransportPutUintByAddr(_dev,x) Space()
-#define IvyTransportPutUint32ByAddr(_dev,x) IvyTransportPutUintByAddr(_dev,x) Space()
-#define IvyTransportPutUint64ByAddr(_dev,x) ivy_p += sprintf(ivy_p, "%llu", *x); Space()
-
-#define IvyTransportPutIntByAddr(_dev,x) ivy_p += sprintf(ivy_p, "%d", *x);
-#define IvyTransportPutInt8ByAddr(_dev,x) IvyTransportPutIntByAddr(_dev,x) Space()
-#define IvyTransportPutInt16ByAddr(_dev,x) IvyTransportPutIntByAddr(_dev,x) Space()
-#define IvyTransportPutInt32ByAddr(_dev,x) IvyTransportPutIntByAddr(_dev,x) Space()
-#define IvyTransportPutInt64ByAddr(_dev,x) ivy_p += sprintf(ivy_p, "%lld", *x); Space()
-
-#define IvyTransportPutOneFloatByAddr(_dev,x) ivy_p += sprintf(ivy_p, "%f", *x);
-#define IvyTransportPutFloatByAddr(_dev,x) IvyTransportPutOneFloatByAddr(_dev,x) Space()
-#define IvyTransportPutDoubleByAddr(_dev,x) IvyTransportPutOneFloatByAddr(_dev,x) Space()
-
-#define IvyTransportPutArray(_dev,_put, _n, _x) { \
-  int __i; \
-  DelimStart(); \
-  for(__i = 0; __i < _n; __i++) { \
-    _put(_dev,&_x[__i]); \
-    Comma(); \
-  } DelimEnd(); Space(); \
-}
-
-#define IvyTransportPutInt8Array(_dev,_n, _x) IvyTransportPutArray(_dev,IvyTransportPutIntByAddr, _n, _x)
-#define IvyTransportPutUint8Array(_dev,_n, _x) IvyTransportPutArray(_dev,IvyTransportPutUintByAddr, _n, _x)
-#define IvyTransportPutCharArray(_dev,_n, _x) IvyTransportPutArray(_dev,IvyTransportPutcByAddr, _n, _x)
-#define IvyTransportPutInt16Array(_dev,_n, _x) IvyTransportPutArray(_dev,IvyTransportPutIntByAddr, _n, _x)
-#define IvyTransportPutUint16Array(_dev,_n, _x) IvyTransportPutArray(_dev,IvyTransportPutUintByAddr, _n, _x)
-#define IvyTransportPutUint32Array(_dev,_n, _x) IvyTransportPutArray(_dev,IvyTransportPutUintByAddr, _n, _x)
-#define IvyTransportPutInt32Array(_dev,_n, _x) IvyTransportPutArray(_dev,IvyTransportPutIntByAddr, _n, _x)
-#define IvyTransportPutUint64Array(_dev,_n, _x) IvyTransportPutArray(_dev,IvyTransportPutUintByAddr, _n, _x)
-#define IvyTransportPutInt64Array(_dev,_n, _x) IvyTransportPutArray(_dev,IvyTransportPutIntByAddr, _n, _x)
-#define IvyTransportPutFloatArray(_dev,_n, _x) IvyTransportPutArray(_dev,IvyTransportPutOneFloatByAddr, _n, _x)
-#define IvyTransportPutDoubleArray(_dev,_n, _x) IvyTransportPutFloatArray(_dev,_n, _x)
-
-#define IvyTransportPutInt8FixedArray(_dev,_n, _x) IvyTransportPutArray(_dev,IvyTransportPutIntByAddr, _n, _x)
-#define IvyTransportPutUint8FixedArray(_dev,_n, _x) IvyTransportPutArray(_dev,IvyTransportPutUintByAddr, _n, _x)
-#define IvyTransportPutCharFixedArray(_dev,_n, _x) IvyTransportPutArray(_dev,IvyTransportPutcByAddr, _n, _x)
-#define IvyTransportPutInt16FixedArray(_dev,_n, _x) IvyTransportPutArray(_dev,IvyTransportPutIntByAddr, _n, _x)
-#define IvyTransportPutUint16FixedArray(_dev,_n, _x) IvyTransportPutArray(_dev,IvyTransportPutUintByAddr, _n, _x)
-#define IvyTransportPutUint32FixedArray(_dev,_n, _x) IvyTransportPutArray(_dev,IvyTransportPutUintByAddr, _n, _x)
-#define IvyTransportPutInt32FixedArray(_dev,_n, _x) IvyTransportPutArray(_dev,IvyTransportPutIntByAddr, _n, _x)
-#define IvyTransportPutUint64FixedArray(_dev,_n, _x) IvyTransportPutArray(_dev,IvyTransportPutUintByAddr, _n, _x)
-#define IvyTransportPutInt64FixedArray(_dev,_n, _x) IvyTransportPutArray(_dev,IvyTransportPutIntByAddr, _n, _x)
-#define IvyTransportPutFloatFixedArray(_dev,_n, _x) IvyTransportPutArray(_dev,IvyTransportPutOneFloatByAddr, _n, _x)
-#define IvyTransportPutDoubleFixedArray(_dev,_n, _x) IvyTransportPutFloatArray(_dev,_n, _x)
diff --git a/sw/airborne/arch/sim/sim_ap.c b/sw/airborne/arch/sim/sim_ap.c
index 9260564c692..dbc4dd7e281 100644
--- a/sw/airborne/arch/sim/sim_ap.c
+++ b/sw/airborne/arch/sim/sim_ap.c
@@ -110,7 +110,7 @@ value update_bat(value bat) {
 }
 
 value update_dl_status(value dl_enabled) {
-  ivy_dl_enabled = Int_val(dl_enabled);
+  ivy_tp.ivy_dl_enabled = Int_val(dl_enabled);
   return Val_unit;
 }
 
diff --git a/sw/airborne/firmwares/fixedwing/main_ap.c b/sw/airborne/firmwares/fixedwing/main_ap.c
index 11477cafe6f..c575369ba8b 100644
--- a/sw/airborne/firmwares/fixedwing/main_ap.c
+++ b/sw/airborne/firmwares/fixedwing/main_ap.c
@@ -78,6 +78,7 @@ PRINT_CONFIG_MSG_VALUE("USE_BARO_BOARD is TRUE, reading onboard baro: ", BARO_BO
 #include "subsystems/datalink/pprz_transport.h"
 #include "subsystems/datalink/xbee.h"
 #include "subsystems/datalink/w5100.h"
+#include "subsystems/datalink/ivy_transport.h"
 
 // modules & settings
 #include "generated/modules.h"
@@ -254,6 +255,9 @@ void init_ap( void ) {
   w5100_init();
 #endif
 #endif /* DATALINK */
+#if SITL
+  ivy_transport_init();
+#endif
 
 #if defined AEROCOMM_DATA_PIN
   IO0DIR |= _BV(AEROCOMM_DATA_PIN);
diff --git a/sw/airborne/firmwares/rotorcraft/main.c b/sw/airborne/firmwares/rotorcraft/main.c
index 044b39f6201..f790c34096a 100644
--- a/sw/airborne/firmwares/rotorcraft/main.c
+++ b/sw/airborne/firmwares/rotorcraft/main.c
@@ -44,6 +44,7 @@
 #include "subsystems/settings.h"
 #include "subsystems/datalink/pprz_transport.h"
 #include "subsystems/datalink/xbee.h"
+#include "subsystems/datalink/ivy_transport.h"
 
 #include "subsystems/commands.h"
 #include "subsystems/actuators.h"
@@ -178,6 +179,9 @@ STATIC_INLINE void main_init( void ) {
 #if DATALINK == XBEE
   xbee_init();
 #endif
+#if SITL
+  ivy_transport_init();
+#endif
 
   // register the timers for the periodic functions
   main_periodic_tid = sys_time_register_timer((1./PERIODIC_FREQUENCY), NULL);
diff --git a/sw/airborne/subsystems/datalink/ivy_transport.c b/sw/airborne/subsystems/datalink/ivy_transport.c
new file mode 100644
index 00000000000..2a458a73617
--- /dev/null
+++ b/sw/airborne/subsystems/datalink/ivy_transport.c
@@ -0,0 +1,178 @@
+/*
+ * Copyright (C) 2003  Pascal Brisset, Antoine Drouin
+ * Copyright (C) 2014  Gautier Hattenberger <gautier.hattenberger@enac.fr>
+ *
+ * This file is part of paparazzi.
+ *
+ * paparazzi is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * paparazzi 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with paparazzi; see the file COPYING.  If not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * @file subsystems/datalink/ivy_transport.c
+ *
+ * Building Paparazzi frames over IVY.
+ *
+ */
+
+#include "std.h"
+#include "subsystems/datalink/ivy_transport.h"
+#include "subsystems/datalink/downlink.h"
+#include "subsystems/datalink/transport.h"
+
+#include <stdio.h>
+#include <Ivy/ivy.h>
+
+struct ivy_transport ivy_tp;
+
+static void put_bytes(struct ivy_transport *trans, struct device *dev __attribute__((unused)), enum TransportDataType type __attribute__((unused)), enum TransportDataFormat format __attribute__((unused)), uint8_t len, const void *bytes)
+{
+  const uint8_t *b = (const uint8_t *) bytes;
+
+  // Start delimiter for arrays
+  if (format == DL_FORMAT_ARRAY) {
+    trans->ivy_p += sprintf(trans->ivy_p, "|");
+  }
+
+  int i = 0;
+  while (i < len) {
+    // print data with correct type
+    switch (type) {
+      case DL_TYPE_CHAR:
+        trans->ivy_p += sprintf(trans->ivy_p, "%c", (char)(*((char*)(b+i))));
+        i++;
+        break;
+      case DL_TYPE_UINT8:
+        trans->ivy_p += sprintf(trans->ivy_p, "%u", b[i]);
+        i++;
+        break;
+      case DL_TYPE_UINT16:
+        trans->ivy_p += sprintf(trans->ivy_p, "%u", (uint16_t)(*((uint16_t*)(b+i))));
+        i += 2;
+        break;
+      case DL_TYPE_UINT32:
+      case DL_TYPE_TIMESTAMP:
+        trans->ivy_p += sprintf(trans->ivy_p, "%u", (uint32_t)(*((uint32_t*)(b+i))));
+        i += 4;
+        break;
+      case DL_TYPE_UINT64:
+        trans->ivy_p += sprintf(trans->ivy_p, "%llu", (uint64_t)(*((uint64_t*)(b+i))));
+        i += 8;
+        break;
+      case DL_TYPE_INT8:
+        trans->ivy_p += sprintf(trans->ivy_p, "%d", (int8_t)(*((int8_t*)(b+i))));
+        i++;
+        break;
+      case DL_TYPE_INT16:
+        trans->ivy_p += sprintf(trans->ivy_p, "%d", (int16_t)(*((int16_t*)(b+i))));
+        i += 2;
+        break;
+      case DL_TYPE_INT32:
+        trans->ivy_p += sprintf(trans->ivy_p, "%d", (int32_t)(*((int32_t*)(b+i))));
+        i += 4;
+        break;
+      case DL_TYPE_INT64:
+        trans->ivy_p += sprintf(trans->ivy_p, "%lld", (int64_t)(*((int64_t*)(b+i))));
+        i += 8;
+        break;
+      case DL_TYPE_FLOAT:
+        trans->ivy_p += sprintf(trans->ivy_p, "%f", (float)(*((float*)(b+i))));
+        i += 4;
+        break;
+      case DL_TYPE_DOUBLE:
+        trans->ivy_p += sprintf(trans->ivy_p, "%f", (double)(*((double*)(b+i))));
+        i += 8;
+        break;
+      case DL_TYPE_ARRAY_LENGTH:
+      default:
+        // Don't print array length but increment index
+        i++;
+        break;
+    }
+    // Coma delimiter for array, space otherwise
+    if (format == DL_FORMAT_ARRAY) {
+      trans->ivy_p += sprintf(trans->ivy_p, ",");
+    } else {
+      trans->ivy_p += sprintf(trans->ivy_p, " ");
+    }
+  }
+
+  // End delimiter for arrays
+  if (format == DL_FORMAT_ARRAY) {
+    trans->ivy_p += sprintf(trans->ivy_p, "| ");
+  }
+}
+
+static void put_named_byte(struct ivy_transport *trans, struct device *dev __attribute__((unused)), enum TransportDataType type __attribute__((unused)), enum TransportDataFormat format __attribute__((unused)), uint8_t byte __attribute__((unused)), const char * name __attribute__((unused)))
+{
+  trans->ivy_p += sprintf(trans->ivy_p, "%s ", name);
+}
+
+static uint8_t size_of(struct ivy_transport *trans __attribute__((unused)), uint8_t len)
+{
+  return len;
+}
+
+static void start_message(struct ivy_transport *trans, struct device *dev __attribute__((unused)), uint8_t payload_len __attribute__((unused)))
+{
+  trans->ivy_p = trans->ivy_buf;
+}
+
+static void end_message(struct ivy_transport *trans, struct device *dev __attribute__((unused)))
+{
+  *(--trans->ivy_p) = '\0';
+  if (trans->ivy_dl_enabled) {
+    IvySendMsg("%s", trans->ivy_buf);
+  }
+}
+
+static void overrun(struct ivy_transport *trans __attribute__((unused)), struct device *dev __attribute__((unused)))
+{
+  downlink_nb_ovrn++;
+}
+
+static void count_bytes(struct ivy_transport *trans __attribute__((unused)), struct device *dev __attribute__((unused)), uint8_t bytes)
+{
+  downlink_nb_bytes += bytes;
+}
+
+static int check_available_space(struct ivy_transport *trans __attribute__((unused)), struct device *dev __attribute__((unused)), uint8_t bytes __attribute__((unused)))
+{
+  return TRUE;
+}
+
+static int check_free_space(struct ivy_transport* p __attribute__((unused)), uint8_t len __attribute__((unused))) { return TRUE; }
+static void transmit(struct ivy_transport* p __attribute__((unused)), uint8_t byte __attribute__((unused))) {}
+static void send_message(struct ivy_transport* p __attribute__((unused))) {}
+
+void ivy_transport_init(void)
+{
+  ivy_tp.ivy_p = ivy_tp.ivy_buf;
+  ivy_tp.ivy_dl_enabled = TRUE;
+
+  ivy_tp.trans_tx.size_of = (size_of_t) size_of;
+  ivy_tp.trans_tx.check_available_space = (check_available_space_t) check_available_space;
+  ivy_tp.trans_tx.put_bytes = (put_bytes_t) put_bytes;
+  ivy_tp.trans_tx.put_named_byte = (put_named_byte_t) put_named_byte;
+  ivy_tp.trans_tx.start_message = (start_message_t) start_message;
+  ivy_tp.trans_tx.end_message = (end_message_t) end_message;
+  ivy_tp.trans_tx.overrun = (overrun_t) overrun;
+  ivy_tp.trans_tx.count_bytes = (count_bytes_t) count_bytes;
+  ivy_tp.trans_tx.impl = (void *)(&ivy_tp);
+  ivy_tp.device.check_free_space = (check_free_space_t) check_free_space;
+  ivy_tp.device.transmit = (transmit_t) transmit;
+  ivy_tp.device.send_message = (send_message_t) send_message;
+  ivy_tp.device.periph = (void *)(&ivy_tp);
+}
diff --git a/sw/airborne/subsystems/datalink/ivy_transport.h b/sw/airborne/subsystems/datalink/ivy_transport.h
new file mode 100644
index 00000000000..7626ae4d514
--- /dev/null
+++ b/sw/airborne/subsystems/datalink/ivy_transport.h
@@ -0,0 +1,53 @@
+/*
+ * Copyright (C) 2003  Pascal Brisset, Antoine Drouin
+ * Copyright (C) 2014  Gautier Hattenberger <gautier.hattenberger@enac.fr>
+ *
+ * This file is part of paparazzi.
+ *
+ * paparazzi is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * paparazzi 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with paparazzi; see the file COPYING.  If not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ */
+
+/**
+ * @file subsystems/datalink/ivy_transport.h
+ *
+ * Building Paparazzi frames over IVY.
+ *
+ */
+
+#ifndef IVY_TRANSPORT_H
+#define IVY_TRANSPORT_H
+
+#include "subsystems/datalink/transport.h"
+#include "mcu_periph/device.h"
+
+// IVY transport
+struct ivy_transport {
+  char ivy_buf[256];
+  char* ivy_p;
+  int ivy_dl_enabled;
+  // generic transmission interface
+  struct transport_tx trans_tx;
+  // generic (dummy) device
+  struct device device;
+};
+
+extern struct ivy_transport ivy_tp;
+
+// Init function
+extern void ivy_transport_init(void);
+
+#endif // IVY_TRANSPORT_H
+
diff --git a/sw/airborne/subsystems/datalink/pprz_transport.c b/sw/airborne/subsystems/datalink/pprz_transport.c
index 5411130fb5f..81b160412b5 100644
--- a/sw/airborne/subsystems/datalink/pprz_transport.c
+++ b/sw/airborne/subsystems/datalink/pprz_transport.c
@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2006  Pascal Brisset, Antoine Drouin
+ * Copyright (C) 2014  Gautier Hattenberger <gautier.hattenberger@enac.fr>
  *
  * This file is part of paparazzi.
  *
@@ -14,12 +15,29 @@
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
- * along with paparazzi; see the file COPYING.  If not, write to
- * the Free Software Foundation, 59 Temple Place - Suite 330,
- * Boston, MA 02111-1307, USA.
+ * along with paparazzi; see the file COPYING.  If not, see
+ * <http://www.gnu.org/licenses/>.
  *
  */
 
+/**
+ * @file subsystems/datalink/pprz_transport.c
+ *
+ * Building and parsing Paparazzi frames.
+ *
+ * Pprz frame:
+ *
+ * |STX|length|... payload=(length-4) bytes ...|Checksum A|Checksum B|
+ *
+ * where checksum is computed over length and payload:
+ * @code
+ * ck_A = ck_B = length
+ * for each byte b in payload
+ *     ck_A += b;
+ *     ck_b += ck_A;
+ * @endcode
+ */
+
 #include <inttypes.h>
 #include "subsystems/datalink/downlink.h"
 #ifndef PPRZ_DATALINK_EXPORT
@@ -37,7 +55,7 @@ static void put_1byte(struct pprz_transport *trans, struct device *dev, const ui
   dev->transmit(dev->periph, byte);
 }
 
-static void put_bytes(struct pprz_transport *trans, struct device *dev, uint8_t len, const void *bytes)
+static void put_bytes(struct pprz_transport *trans, struct device *dev, enum TransportDataType type __attribute__((unused)), enum TransportDataFormat format __attribute__((unused)), uint8_t len, const void *bytes)
 {
   const uint8_t *b = (const uint8_t *) bytes;
   int i;
@@ -46,10 +64,15 @@ static void put_bytes(struct pprz_transport *trans, struct device *dev, uint8_t
   }
 }
 
+static void put_named_byte(struct pprz_transport *trans, struct device *dev, enum TransportDataType type __attribute__((unused)), enum TransportDataFormat format __attribute__((unused)), uint8_t byte, const char * name __attribute__((unused)))
+{
+  put_1byte(trans, dev, byte);
+}
+
 static uint8_t size_of(struct pprz_transport *trans __attribute__((unused)), uint8_t len)
 {
   // message length: payload + protocol overhead (STX + len + ck_a + ck_b = 4)
-  return len + 4;;
+  return len + 4;
 }
 
 static void start_message(struct pprz_transport *trans, struct device *dev, uint8_t payload_len)
@@ -90,6 +113,7 @@ void pprz_transport_init(void)
   pprz_tp.trans_tx.size_of = (size_of_t) size_of;
   pprz_tp.trans_tx.check_available_space = (check_available_space_t) check_available_space;
   pprz_tp.trans_tx.put_bytes = (put_bytes_t) put_bytes;
+  pprz_tp.trans_tx.put_named_byte = (put_named_byte_t) put_named_byte;
   pprz_tp.trans_tx.start_message = (start_message_t) start_message;
   pprz_tp.trans_tx.end_message = (end_message_t) end_message;
   pprz_tp.trans_tx.overrun = (overrun_t) overrun;
diff --git a/sw/airborne/subsystems/datalink/pprzlog_transport.c b/sw/airborne/subsystems/datalink/pprzlog_transport.c
index 74f1186aaa7..3b92e94e440 100644
--- a/sw/airborne/subsystems/datalink/pprzlog_transport.c
+++ b/sw/airborne/subsystems/datalink/pprzlog_transport.c
@@ -54,7 +54,7 @@ static void put_1byte(struct pprzlog_transport *trans, struct device *dev, const
   dev->transmit(dev->periph, byte);
 }
 
-static void put_bytes(struct pprzlog_transport *trans, struct device *dev, uint8_t len, const void *bytes)
+static void put_bytes(struct pprzlog_transport *trans, enum TransportDataType type __attribute__((unused)), enum TransportDataFormat format __attribute__((unused)), struct device *dev, uint8_t len, const void *bytes)
 {
   const uint8_t *b = (const uint8_t *) bytes;
   int i;
@@ -63,6 +63,11 @@ static void put_bytes(struct pprzlog_transport *trans, struct device *dev, uint8
   }
 }
 
+static void put_named_byte(struct pprzlog_transport *trans, struct device *dev, enum TransportDataType type __attribute__((unused)), enum TransportDataFormat format __attribute__((unused)), uint8_t byte, const char * name __attribute__((unused)))
+{
+  put_1byte(trans, dev, byte);
+}
+
 static uint8_t size_of(struct pprzlog_transport *trans __attribute__((unused)), uint8_t len)
 {
   return len;
@@ -75,7 +80,7 @@ static void start_message(struct pprzlog_transport *trans, struct device *dev, u
   trans->ck = 0;
   put_1byte(trans, dev, msg_len);
   uint32_t ts = get_sys_time_usec()/100;
-  put_bytes(trans, dev, 4, (uint8_t*)(&ts));
+  put_bytes(trans, dev, DL_TYPE_TIMESTAMP, DL_FORMAT_SCALAR, 4, (uint8_t*)(&ts));
 }
 
 static void end_message(struct pprzlog_transport *trans, struct device *dev)
@@ -102,6 +107,7 @@ void pprzlog_transport_init(void)
   pprzlog_tp.trans_tx.size_of = (size_of_t) size_of;
   pprzlog_tp.trans_tx.check_available_space = (check_available_space_t) check_available_space;
   pprzlog_tp.trans_tx.put_bytes = (put_bytes_t) put_bytes;
+  pprzlog_tp.trans_tx.put_named_byte = (put_named_byte_t) put_named_byte;
   pprzlog_tp.trans_tx.start_message = (start_message_t) start_message;
   pprzlog_tp.trans_tx.end_message = (end_message_t) end_message;
   pprzlog_tp.trans_tx.overrun = (overrun_t) overrun;
diff --git a/sw/airborne/subsystems/datalink/transport.h b/sw/airborne/subsystems/datalink/transport.h
index 425d7cfa01f..70d55a3fbc0 100644
--- a/sw/airborne/subsystems/datalink/transport.h
+++ b/sw/airborne/subsystems/datalink/transport.h
@@ -53,6 +53,31 @@ struct transport_rx {
 #define TransportLink(_dev, _x) _TransportLink(_dev, _x)
 
 
+/** Data type
+ */
+enum TransportDataType {
+  DL_TYPE_ARRAY_LENGTH,
+  DL_TYPE_CHAR,
+  DL_TYPE_UINT8,
+  DL_TYPE_INT8,
+  DL_TYPE_UINT16,
+  DL_TYPE_INT16,
+  DL_TYPE_UINT32,
+  DL_TYPE_INT32,
+  DL_TYPE_UINT64,
+  DL_TYPE_INT64,
+  DL_TYPE_FLOAT,
+  DL_TYPE_DOUBLE,
+  DL_TYPE_TIMESTAMP
+};
+
+/** Data format (scalar or array)
+ */
+enum TransportDataFormat {
+  DL_FORMAT_SCALAR,
+  DL_FORMAT_ARRAY
+};
+
 /** Function pointers definition
  *
  * they are used to cast the real functions with the correct type
@@ -60,7 +85,8 @@ struct transport_rx {
  */
 typedef uint8_t (*size_of_t)(void *, uint8_t);
 typedef int (*check_available_space_t)(void *, struct device *, uint8_t);
-typedef void (*put_bytes_t)(void *, struct device *, uint8_t, const void *);
+typedef void (*put_bytes_t)(void *, struct device *, enum TransportDataType, enum TransportDataFormat, uint8_t, const void *);
+typedef void (*put_named_byte_t)(void *, struct device *, enum TransportDataType, enum TransportDataFormat, uint8_t, const char *);
 typedef void (*start_message_t)(void *, struct device *, uint8_t);
 typedef void (*end_message_t)(void *, struct device *);
 typedef void (*overrun_t)(void *, struct device *);
@@ -72,6 +98,7 @@ struct transport_tx {
   size_of_t size_of;                              ///< get size of payload with transport header and trailer
   check_available_space_t check_available_space;  ///< check if transmit buffer is not full
   put_bytes_t put_bytes;                          ///< send bytes
+  put_named_byte_t put_named_byte;                ///< send a single byte or its name
   start_message_t start_message;                  ///< transport header
   end_message_t end_message;                      ///< transport trailer
   overrun_t overrun;                              ///< overrun
diff --git a/sw/airborne/subsystems/datalink/xbee.c b/sw/airborne/subsystems/datalink/xbee.c
index c2b985ffa35..dda3eeceeac 100644
--- a/sw/airborne/subsystems/datalink/xbee.c
+++ b/sw/airborne/subsystems/datalink/xbee.c
@@ -59,7 +59,7 @@ static void put_1byte(struct xbee_transport *trans, struct device *dev, const ui
   dev->transmit(dev->periph, byte);
 }
 
-static void put_bytes(struct xbee_transport *trans, struct device *dev, uint8_t len, const void *bytes)
+static void put_bytes(struct xbee_transport *trans, struct device *dev, enum TransportDataType type __attribute__((unused)), enum TransportDataFormat format __attribute__((unused)), uint8_t len, const void *bytes)
 {
   const uint8_t *b = (const uint8_t *) bytes;
   int i;
@@ -68,6 +68,11 @@ static void put_bytes(struct xbee_transport *trans, struct device *dev, uint8_t
   }
 }
 
+static void put_named_byte(struct xbee_transport *trans, struct device *dev, enum TransportDataType type __attribute__((unused)), enum TransportDataFormat format __attribute__((unused)), uint8_t byte, const char * name __attribute__((unused)))
+{
+  put_1byte(trans, dev, byte);
+}
+
 static uint8_t size_of(struct xbee_transport *trans __attribute__((unused)), uint8_t len)
 {
   // message length: payload + API overhead + XBEE TX overhead (868 or 2.4)
@@ -82,7 +87,7 @@ static void start_message(struct xbee_transport *trans, struct device *dev, uint
   dev->transmit(dev->periph, (len & 0xff));
   trans->cs_tx = 0;
   const uint8_t header[] = XBEE_TX_HEADER;
-  put_bytes(trans, dev, XBEE_TX_OVERHEAD + 1, header);
+  put_bytes(trans, dev, DL_TYPE_UINT8, DL_FORMAT_SCALAR, XBEE_TX_OVERHEAD + 1, header);
 }
 
 static void end_message(struct xbee_transport *trans, struct device *dev)
@@ -159,6 +164,7 @@ void xbee_init( void ) {
   xbee_tp.trans_tx.size_of = (size_of_t) size_of;
   xbee_tp.trans_tx.check_available_space = (check_available_space_t) check_available_space;
   xbee_tp.trans_tx.put_bytes = (put_bytes_t) put_bytes;
+  xbee_tp.trans_tx.put_named_byte = (put_named_byte_t) put_named_byte;
   xbee_tp.trans_tx.start_message = (start_message_t) start_message;
   xbee_tp.trans_tx.end_message = (end_message_t) end_message;
   xbee_tp.trans_tx.overrun = (overrun_t) overrun;
diff --git a/sw/tools/generators/gen_messages.ml b/sw/tools/generators/gen_messages.ml
index 432e4d76778..be44aa0a3c2 100644
--- a/sw/tools/generators/gen_messages.ml
+++ b/sw/tools/generators/gen_messages.ml
@@ -41,8 +41,21 @@ let c_type = fun format ->
     | "Uint32" -> "uint32_t"
     | "Uint16" -> "uint16_t"
     | "Uint8" -> "uint8_t"
+    | "Char" -> "char"
     | _ -> failwith (sprintf "gen_messages.c_type: unknown format '%s'" format)
 
+let dl_type = fun format ->
+  match format with
+      "Float" -> "DL_TYPE_FLOAT"
+    | "Double" -> "DL_TYPE_DOUBLE"
+    | "Int32" -> "DL_TYPE_INT32"
+    | "Int16" -> "DL_TYPE_INT16"
+    | "Int8" -> "DL_TYPE_INT8"
+    | "Uint32" -> "DL_TYPE_UINT32"
+    | "Uint16" -> "DL_TYPE_UINT16"
+    | "Uint8" -> "DL_TYPE_UINT8"
+    | "Char" -> "DL_TYPE_CHAR"
+    | _ -> failwith (sprintf "gen_messages.dl_type: unknown format '%s'" format)
 
 type field = _type  * string * format option
 
@@ -132,14 +145,14 @@ module Gen_onboard = struct
   let print_field = fun h (t, name, (_f: format option)) ->
     match t with
         Basic _ ->
-          fprintf h "\t  trans->put_bytes(trans->impl, dev, %s, (void *) _%s);\n" (Syntax.sizeof t) name
+          fprintf h "\t  trans->put_bytes(trans->impl, dev, %s, DL_FORMAT_SCALAR, %s, (void *) _%s);\n" (dl_type (Syntax.nameof t)) (Syntax.sizeof t) name
       | Array (t, varname) ->
           let _s = Syntax.sizeof (Basic t) in
-          fprintf h "\t  trans->put_bytes(trans->impl, dev, 1, (void *) &%s);\n" (Syntax.length_name varname);
-          fprintf h "\t  trans->put_bytes(trans->impl, dev, %s * %s, (void *) _%s);\n" (Syntax.sizeof (Basic t)) (Syntax.length_name varname) name
+          fprintf h "\t  trans->put_bytes(trans->impl, dev, DL_TYPE_ARRAY_LENGTH, DL_FORMAT_SCALAR, 1, (void *) &%s);\n" (Syntax.length_name varname);
+          fprintf h "\t  trans->put_bytes(trans->impl, dev, %s, DL_FORMAT_ARRAY, %s * %s, (void *) _%s);\n" (dl_type (Syntax.nameof (Basic t))) (Syntax.sizeof (Basic t)) (Syntax.length_name varname) name
       | FixedArray (t, varname, len) ->
           let _s = Syntax.sizeof (Basic t) in
-          fprintf h "\t  trans->put_bytes(trans->impl, dev, %s * %d, (void *) _%s);\n" (Syntax.sizeof (Basic t)) len name
+          fprintf h "\t  trans->put_bytes(trans->impl, dev, %s, DL_FORMAT_ARRAY, %s * %d, (void *) _%s);\n" (dl_type (Syntax.nameof (Basic t))) (Syntax.sizeof (Basic t)) len name
 
   let print_macro_param h = function
       (Array _, s, _) -> fprintf h "%s, %s" (Syntax.length_name s) s
@@ -197,8 +210,8 @@ module Gen_onboard = struct
     fprintf h "\tif (trans->check_available_space(trans->impl, dev, trans->size_of(trans->impl, %s +2 /* msg header overhead */))) {\n" size;
     fprintf h "\t  trans->count_bytes(trans->impl, dev, trans->size_of(trans->impl, %s +2 /* msg header overhead */));\n" size;
     fprintf h "\t  trans->start_message(trans->impl, dev, %s +2 /* msg header overhead */);\n" size;
-    fprintf h "\t  uint8_t msg_header[] = { ac_id, DL_%s };\n" s;
-    fprintf h "\t  trans->put_bytes(trans->impl, dev, 2, (void *) msg_header);\n";
+    fprintf h "\t  trans->put_bytes(trans->impl, dev, DL_TYPE_UINT8, DL_FORMAT_SCALAR, 1, &ac_id);\n";
+    fprintf h "\t  trans->put_named_byte(trans->impl, dev, DL_TYPE_UINT8, DL_FORMAT_SCALAR, DL_%s, \"%s\");\n" s s;
     List.iter (print_field h) fields;
     fprintf h "\t  trans->end_message(trans->impl, dev);\n";
     fprintf h "\t} else\n";