diff --git a/sw/airborne/boards/apogee/baro_board.c b/sw/airborne/boards/apogee/baro_board.c
index 27aabe4bfe..c337bdf627 100644
--- a/sw/airborne/boards/apogee/baro_board.c
+++ b/sw/airborne/boards/apogee/baro_board.c
@@ -36,8 +36,31 @@
 #include "subsystems/abi.h"
 #include "led.h"
 
+/** Normal frequency with the default settings
+ *
+ * the baro read function should be called at 5 Hz
+ */
+#ifndef BARO_BOARD_APOGEE_FREQ
+#define BARO_BOARD_APOGEE_FREQ 5
+#endif
+
+/** Baro periodic prescaler
+ *
+ * different for fixedwing and rotorcraft...
+ */
+#ifdef BARO_PERIODIC_FREQUENCY
+#define MPL_PRESCALER ((BARO_PERIODIC_FREQUENCY)/BARO_BOARD_APOGEE_FREQ)
+#else
+#ifdef PERIODIC_FREQUENCY
+#define MPL_PRESCALER ((PERIODIC_FREQUENCY)/BARO_BOARD_APOGEE_FREQ)
+#else
+// default: assuming 60Hz for a 5Hz baro update
+#define MPL_PRESCALER 12
+#endif
+#endif
+
 /** Counter to init ads1114 at startup */
-#define BARO_STARTUP_COUNTER 200
+#define BARO_STARTUP_COUNTER (200/(MPL_PRESCALER))
 uint16_t startup_cnt;
 
 struct Mpl3115 apogee_baro;
@@ -67,17 +90,15 @@ void baro_periodic( void ) {
 #endif
     }
     // Read the sensor
-    mpl3115_periodic(&apogee_baro);
+    RunOnceEvery(MPL_PRESCALER, mpl3115_periodic(&apogee_baro));
   }
 }
 
 void apogee_baro_event(void) {
   mpl3115_event(&apogee_baro);
-  if (apogee_baro.data_available) {
-    if (startup_cnt == 0) {
-      float pressure = ((float)apogee_baro.pressure/(1<<2));
-      AbiSendMsgBARO_ABS(BARO_BOARD_SENDER_ID, &pressure);
-    }
+  if (apogee_baro.data_available && startup_cnt == 0) {
+    float pressure = ((float)apogee_baro.pressure/(1<<2));
+    AbiSendMsgBARO_ABS(BARO_BOARD_SENDER_ID, &pressure);
     apogee_baro.data_available = FALSE;
   }
 }
diff --git a/sw/airborne/peripherals/mpl3115.c b/sw/airborne/peripherals/mpl3115.c
index bfac2abad1..1ca95a416c 100644
--- a/sw/airborne/peripherals/mpl3115.c
+++ b/sw/airborne/peripherals/mpl3115.c
@@ -99,7 +99,7 @@ void mpl3115_read(struct Mpl3115 *mpl)
       mpl->req_trans.buf[0] = MPL3115_REG_CTRL_REG1;
       mpl->req_trans.buf[1] = ((MPL3115_OVERSAMPLING<<3) | (mpl->raw_mode<<6) |
                                (mpl->alt_mode<<7) | MPL3115_OST_BIT);
-      i2c_transmit(mpl->i2c_p, &mpl->trans, mpl->trans.slave_addr, 2);
+      i2c_transmit(mpl->i2c_p, &mpl->req_trans, mpl->trans.slave_addr, 2);
     }
   }
 }