diff --git a/libraries/AP_HAL_AVR_SITL/AnalogIn.cpp b/libraries/AP_HAL_AVR_SITL/AnalogIn.cpp
index e6eafb5b21..7779154155 100644
--- a/libraries/AP_HAL_AVR_SITL/AnalogIn.cpp
+++ b/libraries/AP_HAL_AVR_SITL/AnalogIn.cpp
@@ -34,6 +34,9 @@ float ADCSource::read_latest() {
         return 1023;
         
     case 0:
+        return _sitlState->sonar_pin_value;
+
+    case 1:
         return _sitlState->airspeed_pin_value;
 
     case 12:
diff --git a/libraries/AP_HAL_AVR_SITL/SITL_State.cpp b/libraries/AP_HAL_AVR_SITL/SITL_State.cpp
index 317f751f5d..b2dc1e6eef 100644
--- a/libraries/AP_HAL_AVR_SITL/SITL_State.cpp
+++ b/libraries/AP_HAL_AVR_SITL/SITL_State.cpp
@@ -58,6 +58,7 @@ struct sockaddr_in SITL_State::_rcout_addr;
 pid_t SITL_State::_parent_pid;
 uint32_t SITL_State::_update_count;
 bool SITL_State::_motors_on;
+uint16_t SITL_State::sonar_pin_value;
 uint16_t SITL_State::airspeed_pin_value;
 uint16_t SITL_State::voltage_pin_value;
 uint16_t SITL_State::current_pin_value;
diff --git a/libraries/AP_HAL_AVR_SITL/SITL_State.h b/libraries/AP_HAL_AVR_SITL/SITL_State.h
index 440805a9bf..9cf2a9a2ae 100644
--- a/libraries/AP_HAL_AVR_SITL/SITL_State.h
+++ b/libraries/AP_HAL_AVR_SITL/SITL_State.h
@@ -42,10 +42,11 @@ public:
     static void loop_hook(void);
     uint16_t base_port(void) const { return _base_port; }
 
-    // simulated airspeed
-    static uint16_t airspeed_pin_value;
-    static uint16_t voltage_pin_value;
-    static uint16_t current_pin_value;
+    // simulated airspeed, sonar and battery monitor
+    static uint16_t sonar_pin_value;    // pin 0
+    static uint16_t airspeed_pin_value; // pin 1
+    static uint16_t voltage_pin_value;  // pin 13
+    static uint16_t current_pin_value;  // pin 12
 
 private:
     void _parse_command_line(int argc, char * const argv[]);
diff --git a/libraries/AP_HAL_AVR_SITL/sitl_ins.cpp b/libraries/AP_HAL_AVR_SITL/sitl_ins.cpp
index 357224dce9..68defa322c 100644
--- a/libraries/AP_HAL_AVR_SITL/sitl_ins.cpp
+++ b/libraries/AP_HAL_AVR_SITL/sitl_ins.cpp
@@ -155,12 +155,8 @@ void SITL_State::_update_ins(float roll, 	float pitch, 	float yaw,		// Relative
 	_ins->set_gyro(Vector3f(p, q, r) + _ins->get_gyro_offsets());
 	_ins->set_accel(Vector3f(xAccel, yAccel, zAccel) + _ins->get_accel_offsets());
 
-	// Airspeed and Sonar share the same analog pin.  Connection type is
-	// manually selected.  Crude..
-	if(_sitl->sonar_connected)
-		airspeed_pin_value = _ground_sonar(altitude);
-	else
-		airspeed_pin_value = _airspeed_sensor(airspeed + (_sitl->aspd_noise * _rand_float()));
+        sonar_pin_value    = _ground_sonar(altitude);
+        airspeed_pin_value = _airspeed_sensor(airspeed + (_sitl->aspd_noise * _rand_float()));
 }
 
 #endif
diff --git a/libraries/SITL/SITL.cpp b/libraries/SITL/SITL.cpp
index 932db50405..79a767ecbe 100644
--- a/libraries/SITL/SITL.cpp
+++ b/libraries/SITL/SITL.cpp
@@ -48,9 +48,8 @@ const AP_Param::GroupInfo SITL::var_info[] PROGMEM = {
     AP_GROUPINFO("ASPD_RND",      20, SITL,  aspd_noise,  0.5),
     AP_GROUPINFO("ACCEL_FAIL",    21, SITL,  accel_fail,  0),
     AP_GROUPINFO("BARO_DRIFT",    22, SITL,  baro_drift,  0),
-    AP_GROUPINFO("SONAR_CON",     23, SITL,  sonar_connected, 0),
-    AP_GROUPINFO("SONAR_GLITCH",  24, SITL,  sonar_glitch, 0),
-    AP_GROUPINFO("SONAR_RND",     25, SITL,  sonar_noise, 0),
+    AP_GROUPINFO("SONAR_GLITCH",  23, SITL,  sonar_glitch, 0),
+    AP_GROUPINFO("SONAR_RND",     24, SITL,  sonar_noise, 0),
     AP_GROUPEND
 };
 
diff --git a/libraries/SITL/SITL.h b/libraries/SITL/SITL.h
index 7dd9178ea6..433000901e 100644
--- a/libraries/SITL/SITL.h
+++ b/libraries/SITL/SITL.h
@@ -55,7 +55,6 @@ public:
 	AP_Float mag_error;   // in degrees
     AP_Float servo_rate;  // servo speed in degrees/second
 
-    AP_Float sonar_connected; // Analogue sonar connected to AnalogPin 0 (else airspeed)
     AP_Float sonar_glitch;// probablility between 0-1 that any given sonar sample will read as max distance
     AP_Float sonar_noise; // in metres