Copter: Moving to RSSI library for reading various kinds of RSSI, with the possibility of adding more.

* Retains ability to read from Analog Pin
* Adds ability to read RSSI from PWM channel value as is done in OpenLRSng, EazyUHF, and various other LRS.
* Handles any type of RSSI that provides RSSI values inverted - i.e. when the low value is the best signal and the high value is the worst signal.
* Has different key names from all existing RSSI parameters to provide for a clean break and easier distinguishing.
* Existing parameters are marked as obsolete

ArduCopter/Copter.cpp

@@ -102,7 +102,6 @@ Copter::Copter(void) :
 #if CAMERA == ENABLED
     camera(&relay),
 #endif
-    rssi_analog_source(NULL),
 #if MOUNT == ENABLED
     camera_mount(ahrs, current_loc),
 #endif

ArduCopter/Copter.h

@@ -75,6 +75,7 @@
 #include <AP_Motors/AP_Motors.h>          // AP Motors library
 #include <AP_RangeFinder/AP_RangeFinder.h>     // Range finder library
 #include <AP_OpticalFlow/AP_OpticalFlow.h>     // Optical Flow library
+#include <AP_RSSI/AP_RSSI.h>                   // RSSI Library
 #include <Filter/Filter.h>             // Filter library
 #include <AP_Buffer/AP_Buffer.h>          // APM FIFO Buffer
 #include <AP_Relay/AP_Relay.h>           // APM relay
@@ -451,9 +452,6 @@ private:
     AP_Camera camera;
 #endif
 
-    // a pin for reading the receiver RSSI voltage.
-    AP_HAL::AnalogSource* rssi_analog_source;
-
     // Camera/Antenna mount tracking and stabilisation stuff
 #if MOUNT == ENABLED
     // current_loc uses the baro/gps soloution for altitude rather than gps only.
@@ -470,6 +468,9 @@ private:
     AP_Rally rally;
 #endif
 
+    // RSSI 
+    AP_RSSI rssi;      
+
     // Crop Sprayer
 #if SPRAYER == ENABLED
     AC_Sprayer sprayer;

ArduCopter/Parameters.cpp

@@ -205,21 +205,6 @@ const AP_Param::Info Copter::var_info[] PROGMEM = {
     // @User: Standard
     GSCALAR(rtl_climb_min,  "RTL_CLIMB_MIN",    RTL_CLIMB_MIN_DEFAULT),
 
-    // @Param: RSSI_PIN
-    // @DisplayName: Receiver RSSI sensing pin
-    // @Description: This selects an analog pin for the receiver RSSI voltage. It assumes the voltage is RSSI_RANGE for max rssi, 0V for minimum
-    // @Values: -1:Disabled, 0:APM2 A0, 1:APM2 A1, 2:APM2 A2, 13:APM2 A13, 103:Pixhawk SBUS
-    // @User: Standard
-    GSCALAR(rssi_pin,            "RSSI_PIN",         -1),
-
-    // @Param: RSSI_RANGE
-    // @DisplayName: Receiver RSSI voltage range
-    // @Description: Receiver RSSI voltage range
-    // @Units: Volt
-    // @Values: 3.3:3.3V, 5:5V
-    // @User: Standard
-    GSCALAR(rssi_range,          "RSSI_RANGE",         5.0f),
-
     // @Param: WP_YAW_BEHAVIOR
     // @DisplayName: Yaw behaviour during missions
     // @Description: Determines how the autopilot controls the yaw during missions and RTL
@@ -1033,6 +1018,10 @@ const AP_Param::Info Copter::var_info[] PROGMEM = {
     // @Path: ../libraries/AP_Mission/AP_Mission.cpp
     GOBJECT(mission, "MIS_",       AP_Mission),
 
+    // @Group: RSSI_
+    // @Path: ../libraries/AP_RSSI/AP_RSSI.cpp
+    GOBJECT(rssi, "RSSI_",  AP_RSSI),      
+    
 #if CONFIG_SONAR == ENABLED
     // @Group: RNGFND
     // @Path: ../libraries/AP_RangeFinder/RangeFinder.cpp

ArduCopter/Parameters.h

@@ -90,7 +90,7 @@ public:
                                                 // change
         k_param_toy_yaw_rate,                   // deprecated - remove
         k_param_crosstrack_min_distance,	// deprecated - remove with next eeprom number change
-        k_param_rssi_pin,
+        k_param_rssi_pin,                   // unused, replaced by rssi_ library parameters
         k_param_throttle_accel_enabled,     // deprecated - remove
         k_param_wp_yaw_behavior,
         k_param_acro_trainer,
@@ -105,7 +105,7 @@ public:
         k_param_battery,
         k_param_fs_batt_mah,
         k_param_angle_rate_max,         // remove
-        k_param_rssi_range,
+        k_param_rssi_range,             // unused, replaced by rssi_ library parameters
         k_param_rc_feel_rp,
         k_param_NavEKF,                 // Extended Kalman Filter Inertial Navigation Group
         k_param_mission,                // mission library
@@ -167,6 +167,9 @@ public:
         //
         k_param_motors = 90,
 
+        // 97: RSSI
+        k_param_rssi = 97,
+                
         //
         // 100: Inertial Nav
         //
@@ -375,8 +378,6 @@ public:
     AP_Int16        rtl_alt_final;
     AP_Int16        rtl_climb_min;              // rtl minimum climb in cm
 
-    AP_Int8         rssi_pin;
-    AP_Float        rssi_range;                 // allows to set max voltage for rssi pin such as 5.0, 3.3 etc. 
     AP_Int8         wp_yaw_behavior;            // controls how the autopilot controls yaw during missions
     AP_Int8         rc_feel_rp;                 // controls vehicle response to user input with 0 being extremely soft and 100 begin extremely crisp
 

ArduCopter/make.inc

@@ -38,6 +38,7 @@ LIBRARIES += RC_Channel
 LIBRARIES += AP_Motors
 LIBRARIES += AP_RangeFinder
 LIBRARIES += AP_OpticalFlow
+LIBRARIES += AP_RSSI
 LIBRARIES += Filter
 LIBRARIES += AP_Buffer
 LIBRARIES += AP_Relay

ArduCopter/sensors.cpp

@@ -171,14 +171,7 @@ void Copter::read_battery(void)
 // RC_CHANNELS_SCALED message
 void Copter::read_receiver_rssi(void)
 {
-    // avoid divide by zero
-    if (g.rssi_range <= 0) {
-        receiver_rssi = 0;
-    }else{
-        rssi_analog_source->set_pin(g.rssi_pin);
-        float ret = rssi_analog_source->voltage_average() * 255 / g.rssi_range;
-        receiver_rssi = constrain_int16(ret, 0, 255);
-    }
+    receiver_rssi = rssi.read_receiver_rssi_uint8();
 }
 
 #if EPM_ENABLED == ENABLED

ArduCopter/system.cpp

@@ -122,9 +122,10 @@ void Copter::init_ardupilot()
 
     // initialise battery monitor
     battery.init();
-    
-    rssi_analog_source      = hal.analogin->channel(g.rssi_pin);
 
+    // Init RSSI
+    rssi.init();
+    
     barometer.init();
 
     // Register the mavlink service callback. This will run