diff --git a/conf/airframes/PPZUAV/fixed-wing/ppzimu_tiny.xml b/conf/airframes/PPZUAV/fixed-wing/ppzimu_tiny.xml
index d60dfa5734..0fd3bd0c2e 100644
--- a/conf/airframes/PPZUAV/fixed-wing/ppzimu_tiny.xml
+++ b/conf/airframes/PPZUAV/fixed-wing/ppzimu_tiny.xml
@@ -44,9 +44,9 @@
 
   <section name="IMU" prefix="IMU_">
     <!-- Calibration Neutral -->
-    <define name="GYRO_P_NEUTRAL" value="-7"/>
-    <define name="GYRO_Q_NEUTRAL" value="-77"/>
-    <define name="GYRO_R_NEUTRAL" value="-23"/>
+    <define name="GYRO_P_NEUTRAL" value="0"/>
+    <define name="GYRO_Q_NEUTRAL" value="0"/>
+    <define name="GYRO_R_NEUTRAL" value="0"/>
 
     <!-- SENS = 14.375 LSB/(deg/sec) * 57.6 deg/rad = 828 LSB/rad/sec / 12bit FRAC: 4096 / 828 -->
     <define name="GYRO_P_SENS" value="4.947" integer="16"/>
@@ -60,12 +60,12 @@
     <define name="GYRO_R_P" value="0."/>
     <define name="GYRO_R_Q" value="0."/>
 
-    <define name="GYRO_P_SIGN" value="-1"/>
+    <define name="GYRO_P_SIGN" value="1"/>
     <define name="GYRO_Q_SIGN" value="1"/>
     <define name="GYRO_R_SIGN" value="1"/>
 
-    <define name="ACCEL_X_NEUTRAL" value="12"/>
-    <define name="ACCEL_Y_NEUTRAL" value="2"/>
+    <define name="ACCEL_X_NEUTRAL" value="0"/>
+    <define name="ACCEL_Y_NEUTRAL" value="0"/>
     <define name="ACCEL_Z_NEUTRAL" value="0"/>
 
     <!-- SENS = 256 LSB/g @ 2.5V [X&Y: 265 LSB/g @ 3.3V] / 9.81 ms2/g = 26.095 LSB/ms2 / 10bit FRAC: 1024 / 26.095 for z and 1024 / 27.01 for X&Y -->
@@ -74,7 +74,7 @@
     <define name="ACCEL_Z_SENS" value="39.24" integer="16"/>
 
     <define name="ACCEL_X_SIGN" value="1"/>
-    <define name="ACCEL_Y_SIGN" value="-1"/>
+    <define name="ACCEL_Y_SIGN" value="1"/>
     <define name="ACCEL_Z_SIGN" value="1"/>
 
     <define name="MAG_X_NEUTRAL" value="0"/>
@@ -260,7 +260,10 @@
 
 ap.CFLAGS +=    -DAHRS_H_X=0.51562740288882 -DAHRS_H_Y=-0.05707735220832 -DAHRS_H_Z=0.85490967783446
 ap.CFLAGS +=    -DIMU_TYPE_H=\"modules/ins/ins_ppzuavimu.h\"
-# -DOUTPUTMODE=2
+
+# Test attitude using accelerometers only:
+# ap.CFLAGS +=   -DOUTPUTMODE=2
+# ap.CFLAGS +=   -DASPIRIN_IMU
  </makefile>
 
 </airframe>
diff --git a/sw/airborne/modules/ins/ins_ppzuavimu.c b/sw/airborne/modules/ins/ins_ppzuavimu.c
index 73cf7ce5e7..2f7394ab89 100644
--- a/sw/airborne/modules/ins/ins_ppzuavimu.c
+++ b/sw/airborne/modules/ins/ins_ppzuavimu.c
@@ -39,16 +39,10 @@
 #include "../../peripherals/hmc5843.h"
 
 // Results
-int32_t mag_x, mag_y, mag_z;
 volatile bool_t mag_valid;
-
-int32_t gyr_x, gyr_y, gyr_z;
 volatile bool_t gyr_valid;
-
-int32_t acc_x, acc_y, acc_z;
 volatile bool_t acc_valid;
 
-
 // Communication
 struct i2c_transaction ppzuavimu_hmc5843;
 struct i2c_transaction ppzuavimu_itg3200;
@@ -166,38 +160,45 @@ void ppzuavimu_module_periodic( void )
 
 void ppzuavimu_module_downlink_raw( void )
 {
-  DOWNLINK_SEND_IMU_GYRO_RAW(DefaultChannel,&gyr_x,&gyr_y,&gyr_z);
-  DOWNLINK_SEND_IMU_ACCEL_RAW(DefaultChannel,&acc_x,&acc_y,&acc_z);
-  DOWNLINK_SEND_IMU_MAG_RAW(DefaultChannel,&mag_x,&mag_y,&mag_z);
+  DOWNLINK_SEND_IMU_GYRO_RAW(DefaultChannel,&imu.gyro_unscaled.p,&imu.gyro_unscaled.q,&imu.gyro_unscaled.r);
+  DOWNLINK_SEND_IMU_ACCEL_RAW(DefaultChannel,&imu.accel_unscaled.x,&imu.accel_unscaled.y,&imu.accel_unscaled.z);
+  DOWNLINK_SEND_IMU_MAG_RAW(DefaultChannel,&imu.mag_unscaled.x,&imu.mag_unscaled.y,&imu.mag_unscaled.z);
 }
 
 void ppzuavimu_module_event( void )
 {
+  int32_t x, y, z;
+
   // If the itg3200 I2C transaction has succeeded: convert the data
   if (ppzuavimu_itg3200.status == I2CTransSuccess)
   {
-    gyr_x = (int16_t) ((ppzuavimu_itg3200.buf[0] << 8) | ppzuavimu_itg3200.buf[1]);
-    gyr_y = (int16_t) ((ppzuavimu_itg3200.buf[2] << 8) | ppzuavimu_itg3200.buf[3]);
-    gyr_z = (int16_t) ((ppzuavimu_itg3200.buf[4] << 8) | ppzuavimu_itg3200.buf[5]);
+    x = (int16_t) ((ppzuavimu_itg3200.buf[0] << 8) | ppzuavimu_itg3200.buf[1]);
+    y = (int16_t) ((ppzuavimu_itg3200.buf[2] << 8) | ppzuavimu_itg3200.buf[3]);
+    z = (int16_t) ((ppzuavimu_itg3200.buf[4] << 8) | ppzuavimu_itg3200.buf[5]);
 
+    // Signs depend on the way sensors are soldered on the board: so they are hardcoded
 #ifdef ASPIRIN_IMU
-    RATES_ASSIGN(imu.gyro_unscaled, gyr_x, gyr_y, gyr_z);
-#else
-    RATES_ASSIGN(imu.gyro_unscaled, gyr_x, gyr_y, gyr_z);
+    RATES_ASSIGN(imu.gyro_unscaled, x, -y, -z);
+#else // PPZIMU
+    RATES_ASSIGN(imu.gyro_unscaled, -x, y, -z);
 #endif
 
     gyr_valid = TRUE;
-    ppzuavimu_itg3200.status = I2CTransDone;
+    ppzuavimu_itg3200.status = I2CTransDone;  // remove the I2CTransSuccess status, otherwise data ready will be triggered again without new data
   }
 
   // If the adxl345 I2C transaction has succeeded: convert the data
   if (ppzuavimu_adxl345.status == I2CTransSuccess)
   {
-    acc_x = (int16_t) ((ppzuavimu_adxl345.buf[1] << 8) | ppzuavimu_adxl345.buf[0]);
-    acc_y = (int16_t) ((ppzuavimu_adxl345.buf[3] << 8) | ppzuavimu_adxl345.buf[2]);
-    acc_z = (int16_t) ((ppzuavimu_adxl345.buf[5] << 8) | ppzuavimu_adxl345.buf[4]);
+    x = (int16_t) ((ppzuavimu_adxl345.buf[1] << 8) | ppzuavimu_adxl345.buf[0]);
+    y = (int16_t) ((ppzuavimu_adxl345.buf[3] << 8) | ppzuavimu_adxl345.buf[2]);
+    z = (int16_t) ((ppzuavimu_adxl345.buf[5] << 8) | ppzuavimu_adxl345.buf[4]);
 
-    VECT3_ASSIGN(imu.accel_unscaled, acc_x, acc_y, acc_z);
+#ifdef ASPIRIN_IMU
+    VECT3_ASSIGN(imu.accel_unscaled, -x, y, z);
+#else // PPZIMU
+    VECT3_ASSIGN(imu.accel_unscaled, x, -y, z);
+#endif
 
     acc_valid = TRUE;
     ppzuavimu_adxl345.status = I2CTransDone;
@@ -206,9 +207,16 @@ void ppzuavimu_module_event( void )
   // If the hmc5843 I2C transaction has succeeded: convert the data
   if (ppzuavimu_hmc5843.status == I2CTransSuccess)
   {
-    mag_x = (int16_t) ((ppzuavimu_hmc5843.buf[0] << 8) | ppzuavimu_hmc5843.buf[1]);
-    mag_y = (int16_t) ((ppzuavimu_hmc5843.buf[2] << 8) | ppzuavimu_hmc5843.buf[3]);
-    mag_z = (int16_t) ((ppzuavimu_hmc5843.buf[4] << 8) | ppzuavimu_hmc5843.buf[5]);
+    x = (int16_t) ((ppzuavimu_hmc5843.buf[0] << 8) | ppzuavimu_hmc5843.buf[1]);
+    y = (int16_t) ((ppzuavimu_hmc5843.buf[2] << 8) | ppzuavimu_hmc5843.buf[3]);
+    z = (int16_t) ((ppzuavimu_hmc5843.buf[4] << 8) | ppzuavimu_hmc5843.buf[5]);
+
+#ifdef ASPIRIN_IMU
+    VECT3_ASSIGN(imu.mag_unscaled, x, y, z);
+#else // PPZIMU
+    VECT3_ASSIGN(imu.mag_unscaled, x, y, z);
+#endif
+
     mag_valid = TRUE;
     ppzuavimu_hmc5843.status = I2CTransDone;
   }