[modules] airspeed_ets: add 3rd party mode support

Add option to use the raw value. This is needed when the sensor is in third-party mode.

closes paparazzi#1099

conf/modules/airspeed_ets.xml

@@ -8,8 +8,9 @@
       Has only been tested with V3 of the sensor hardware.
 
       Notes:
-      Connect directly to TWOG/Tiny I2C port. Multiple sensors can be chained together.
-      Sensor should be in the proprietary mode (default) and not in 3rd party mode.
+      Connect directly to TWOG/Tiny/Lisa I2C port. Multiple sensors can be chained together.
+      Sensor may be in the proprietary mode (default) or in 3rd-party mode. In 3rd-party mode you must define AIRSPEED_ETS_3RD_PARTY_MODE.
+      A eLogger is needed to set sensor to 3rd-party mode, which is supposed to be more reliable than the default mode.
 
       Sensor module wire assignments:
       - Red wire: 5V
@@ -18,11 +19,12 @@
       - Brown wire: SCL
     </description>
     <define name="AIRSPEED_ETS_I2C_DEV" value="i2cX" description="set i2c peripheral (default: i2c0)"/>
-    <define name="AIRSPEED_ETS_OFFSET" value="offset" description="sensor reading offset (default: 0)"/>
-    <define name="AIRSPEED_ETS_SCALE" value="scale" description="sensor scale factor (default: 1.8)"/>
+    <define name="AIRSPEED_ETS_OFFSET" value="offset" description="sensor reading offset for sensor in proprietary mode (default: 0)"/>
+    <define name="AIRSPEED_ETS_SCALE" value="scale" description="sensor scale factor for sensor in proprietary mode  (default: 1.8)"/>
     <define name="AIRSPEED_ETS_START_DELAY" value="delay" description="set initial start delay in seconds"/>
     <define name="AIRSPEED_ETS_SYNC_SEND" description="flag to transmit the data as it is acquired"/>
     <define name="USE_AIRSPEED_ETS" value="TRUE|FALSE" description="set airspeed in state interface"/>
+    <define name="AIRSPEED_ETS_3RD_PARTY_MODE"  description="read raw value for sensor in third-party mode"/>
   </doc>
 
   <header>

sw/airborne/modules/sensors/airspeed_ets.c

@@ -30,6 +30,7 @@
  * Notes:
  * Connect directly to TWOG/Tiny I2C port. Multiple sensors can be chained together.
  * Sensor should be in the proprietary mode (default) and not in 3rd party mode.
+ * Define AIRSPEED_ETS_3RD_PARTY_MODE to run it in 3rd party mode.
  *
  * Sensor module wire assignments:
  * Red wire: 5V
@@ -156,6 +157,7 @@ void airspeed_ets_read_event(void)
 
   // Continue only if a new airspeed value was received
   if (airspeed_ets_valid) {
+#if !AIRSPEED_ETS_3RD_PARTY_MODE
     // Calculate offset average if not done already
     if (!airspeed_ets_offset_init) {
       --airspeed_ets_cnt;
@@ -190,6 +192,11 @@ void airspeed_ets_read_event(void)
     else {
       airspeed_tmp = 0.0;
     }
+//use raw value for sensor set to third-party mode
+#else
+    airspeed_tmp = airspeed_ets_raw;
+#endif    //AIRSPEED_ETS_3RD_PARTY_MODE
+
     // Airspeed should always be positive
     if (airspeed_tmp < 0.0) {
       airspeed_tmp = 0.0;