Sonar - changed default pin to A0

ArduCopter/config.h

@@ -176,7 +176,7 @@
 # endif
 #elif CONFIG_SONAR_SOURCE == SONAR_SOURCE_ANALOG_PIN
 # ifndef CONFIG_SONAR_SOURCE_ANALOG_PIN
-#  define CONFIG_SONAR_SOURCE_ANALOG_PIN A1
+#  define CONFIG_SONAR_SOURCE_ANALOG_PIN A0
 # endif
 #else
 # warning Invalid value for CONFIG_SONAR_SOURCE, disabling sonar

libraries/AP_RangeFinder/examples/AP_RangeFinder_test/AP_RangeFinder_test.pde

@@ -30,7 +30,7 @@ ModeFilter mode_filter;
     AP_ADC_ADS7844 adc;
     AP_AnalogSource_ADC adc_source(&adc, AP_RANGEFINDER_PITOT_TYPE_ADC_CHANNEL, 0.25);    // use Pitot tube
 #else
-    AP_AnalogSource_Arduino adc_source(A1);   // use AN1 analog pin (APM1: on oilpan at back right near the CLI switch.  APM2: on left)
+    AP_AnalogSource_Arduino adc_source(A0);   // use AN0 analog pin for APM2 on left
 #endif
 
 // create the range finder object