ArduCopter: BATT_PIN parameter added to allow you to select which pin is used for voltage and current measurements

To save a parameter, the current sensor pin is assumed to always be 1 higher than the voltage pin.

ArduCopter/Parameters.h

@@ -114,8 +114,9 @@ public:
         k_param_ch7_option,
         k_param_auto_slew_rate,
         k_param_sonar_type,
-        k_param_super_simple = 155,
-        k_param_axis_enabled = 157,
+        k_param_super_simple,
+        k_param_battery_pin,
+        k_param_axis_enabled,
         k_param_copter_leds_mode,
         k_param_ahrs, // AHRS group
 
@@ -236,6 +237,7 @@ public:
     AP_Int8         optflow_enabled;
     AP_Float        low_voltage;
     AP_Int8         super_simple;
+    AP_Int8         battery_pin;
     AP_Int16        rtl_approach_alt;
     AP_Int8         tilt_comp;
     AP_Int8         axis_enabled;

ArduCopter/Parameters.pde

@@ -98,6 +98,13 @@ const AP_Param::Info var_info[] PROGMEM = {
     // @User: Standard
     GSCALAR(super_simple,   "SUPER_SIMPLE",     SUPER_SIMPLE),
 
+    // @Param: BATT_PIN
+    // @DisplayName: Battery Voltage sending pin
+    // @Description: Setting this to 0 ~ 11 will enable battery voltage sending on pins A0 ~ A11.  Current will be measured on this pin + 1
+    // @Values: 99:Disabled, 0:A0, 1:A1, 10:A10
+    // @User: Standard
+    GSCALAR(battery_pin,    "BATT_PIN",         BATTERY_PIN_1),
+
     // @Param: APPROACH_ALT
     // @DisplayName: RTL Approach Altitude
     // @Description: This is the altitude the vehicle will move to as the final stage of Returning to Launch.  Set to zero to land.

ArduCopter/config.h

@@ -140,8 +140,7 @@
  # define USB_MUX_PIN      -1
  # define CLI_SLIDER_ENABLED DISABLED
  # define OPTFLOW_CS_PIN   34
- # define BATTERY_PIN_1      0
- # define CURRENT_PIN_1      1
+ # define BATTERY_PIN_1      0      // Battery voltage on A0, Current on A1
 #elif CONFIG_APM_HARDWARE == APM_HARDWARE_APM2
  # define A_LED_PIN        27
  # define B_LED_PIN        26
@@ -153,8 +152,7 @@
  # define CLI_SLIDER_ENABLED DISABLED
  # define USB_MUX_PIN      23
  # define OPTFLOW_CS_PIN   A3
- # define BATTERY_PIN_1      1
- # define CURRENT_PIN_1      2
+ # define BATTERY_PIN_1      1      // Battery voltage on A1, Current on A2
 #endif
 
 ////////////////////////////////////////////////////////////////////////////////

ArduCopter/sensors.pde

@@ -77,11 +77,11 @@ static void read_battery(void)
     }
 
     if(g.battery_monitoring == 3 || g.battery_monitoring == 4) {
-        static AP_AnalogSource_Arduino bat_pin(BATTERY_PIN_1);
+        static AP_AnalogSource_Arduino bat_pin(g.battery_pin);
         battery_voltage1 = BATTERY_VOLTAGE(bat_pin.read_average());
     }
     if(g.battery_monitoring == 4) {
-        static AP_AnalogSource_Arduino current_pin(CURRENT_PIN_1);
+        static AP_AnalogSource_Arduino current_pin(g.battery_pin+1);    // current is always read from one pin higher than battery voltage
         current_amps1    = CURRENT_AMPS(current_pin.read_average());
         current_total1   += current_amps1 * 0.02778;            // called at 100ms on average, .0002778 is 1/3600 (conversion to hours)
     }