diff --git a/sw/airborne/anemotaxis.c b/sw/airborne/anemotaxis.c
index aed9b00146..816cf17b18 100644
--- a/sw/airborne/anemotaxis.c
+++ b/sw/airborne/anemotaxis.c
@@ -5,8 +5,7 @@
 #include "nav.h"
 #include "flight_plan.h"
 #include "ap_downlink.h"
-
-uint8_t chemo_sensor;
+#include "chemo_detect.h"
 
 enum status { UTURN, CROSSWIND };
 static enum status status;
diff --git a/sw/airborne/anemotaxis.h b/sw/airborne/anemotaxis.h
index c6d7f2e7a2..16e571b252 100644
--- a/sw/airborne/anemotaxis.h
+++ b/sw/airborne/anemotaxis.h
@@ -3,7 +3,6 @@
 
 #include "std.h"
 
-extern uint8_t chemo_sensor;
 extern bool_t nav_anemotaxis_downwind(uint8_t c, float radius);
 extern bool_t nav_anemotaxis_init(uint8_t c);
 extern bool_t nav_anemotaxis(uint8_t c, uint8_t c1, uint8_t c2, uint8_t plume);
diff --git a/sw/airborne/chemo_detect.c b/sw/airborne/chemo_detect.c
index eb1b4aa457..32cb7e776b 100644
--- a/sw/airborne/chemo_detect.c
+++ b/sw/airborne/chemo_detect.c
@@ -4,7 +4,7 @@
 #define DETECT_PERIOD 8 /* *4Hz */
 #define THRESHOLD 150
 
-uint8_t chemo_sensor;
+uint16_t chemo_sensor;
 
 void chemo_init( void ) {
   chemo_sensor = 0;
@@ -16,8 +16,10 @@ void chemo_periodic( void ) {
 
   /* Detection on the first sensor */
   int dval = enose_val[0] - vals[0][idx];
-  if (dval < -THRESHOLD)
-    chemo_sensor = Min(-dval, 0xff);
+  if (dval < -THRESHOLD) {
+    chemo_sensor = -dval;
+  } else
+    chemo_sensor = 0;
 
   int i;
   for(i = 0; i < ENOSE_NB_SENSOR; i++)
diff --git a/sw/airborne/chemo_detect.h b/sw/airborne/chemo_detect.h
index cc6a2daeab..b0a5e1062c 100644
--- a/sw/airborne/chemo_detect.h
+++ b/sw/airborne/chemo_detect.h
@@ -3,8 +3,8 @@
 
 #include "std.h"
 
-extern uint8_t chemo_sensor;
-#define MAX_CHEMO 255
+extern uint16_t chemo_sensor;
+#define MAX_CHEMO 400
 
 void chemo_init( void );
 void chemo_periodic( void );
diff --git a/sw/airborne/chemotaxis.c b/sw/airborne/chemotaxis.c
index 1fb3609f3f..e2865ab1b9 100644
--- a/sw/airborne/chemotaxis.c
+++ b/sw/airborne/chemotaxis.c
@@ -5,14 +5,12 @@
 #include "nav.h"
 #include "flight_plan.h"
 #include "ap_downlink.h"
-
-uint8_t chemo_sensor;
+#include "chemo_detect.h"
 
 #define MAX_RADIUS 250
 #define ALPHA 0.5
 
 static uint8_t last_plume_value;
-#define MAX_CHEMO 255
 
 static float radius;
 static int8_t sign;
@@ -23,7 +21,6 @@ bool_t nav_chemotaxis_init( uint8_t c, uint8_t plume ) {
   sign = 1;
   waypoints[plume].x = waypoints[c].x;
   waypoints[plume].y = waypoints[c].y;
-  chemo_sensor = 0;
   return FALSE;
 }
 
diff --git a/sw/airborne/enose.c b/sw/airborne/enose.c
index c78984dfef..4f8d833172 100644
--- a/sw/airborne/enose.c
+++ b/sw/airborne/enose.c
@@ -68,9 +68,15 @@ void enose_periodic( void ) {
       enose_i2c_done = FALSE;
     }
     else if (enose_status == ENOSE_MEASURING_RD) {
-      enose_val[0] = (i2c_buf[0]<<8) | i2c_buf[1];
-      enose_val[1] = (i2c_buf[2]<<8) | i2c_buf[3];
-      enose_val[2] = (i2c_buf[4]<<8) | i2c_buf[5];
+      uint16_t val = (i2c_buf[0]<<8) | i2c_buf[1];
+      if (val < 5000) 
+	enose_val[0] = val;
+      val = (i2c_buf[2]<<8) | i2c_buf[3];
+      if (val < 5000) 
+	enose_val[1] = val;
+      val = (i2c_buf[4]<<8) | i2c_buf[5];
+      if (val < 5000) 
+	enose_val[2] = val;
       enose_status = ENOSE_IDLE;
     }
   }