AC_Sprayer: correct HOWTO, minor cleanups (NFC)

libraries/AC_Sprayer/AC_Sprayer.cpp

@@ -63,10 +63,6 @@ AC_Sprayer::AC_Sprayer(const AP_InertialNav* inav) :
         _spinner_pwm.set_and_save(AC_SPRAYER_DEFAULT_SPINNER_PWM);
     }
 
-    // initialise flags
-    _flags.spraying = false;
-    _flags.testing = false;
-
     // To-Do: ensure that the pump and spinner servo channels are enabled
 }
 
@@ -96,9 +92,6 @@ void AC_Sprayer::enable(bool true_false)
 void
 AC_Sprayer::update()
 {
-    uint32_t now;
-    float ground_speed;
-
     // exit immediately if we are disabled (perhaps set pwm values back to defaults)
     if (!_enabled) {
         return;
@@ -111,10 +104,10 @@ AC_Sprayer::update()
 
     // get horizontal velocity
     const Vector3f &velocity = _inav->get_velocity();
-    ground_speed = norm(velocity.x,velocity.y);
+    float ground_speed = norm(velocity.x,velocity.y);
 
     // get the current time
-    now = AP_HAL::millis();
+    const uint32_t now = AP_HAL::millis();
 
     // check our speed vs the minimum
     if (ground_speed >= _speed_min) {
@@ -134,7 +127,7 @@ AC_Sprayer::update()
         // reset the speed under timer
         _speed_under_min_time = 0;
     }else{
-        // we are under the min speed.  If we are spraying
+        // we are under the min speed.
         if (_flags.spraying) {
             // set the timer if this is the first time we've dropped below the min speed
             if (_speed_under_min_time == 0) {

libraries/AC_Sprayer/AC_Sprayer.h

@@ -3,16 +3,14 @@
 
 /**
     The crop spraying functionality can be enabled in ArduCopter by doing the following:
-        1. add this line to APM_Config.h
-            #define SPRAYER ENABLED
-        2. set CH7_OPT or CH8_OPT parameter to 15 to allow turning the sprayer on/off from one of these channels
-        3. set RC10_FUNCTION to 22 to enable the servo output controlling the pump speed on RC10
-        4. set RC11_FUNCTION to 23 to enable the spervo output controlling the spinner on RC11
-        5. ensure the RC10_MIN, RC10_MAX, RC11_MIN, RC11_MAX accurately hold the min and maximum servo values you could possibly output to the pump and spinner
-        6. set the SPRAY_SPINNER to the pwm value the spinner should spin at when on
-        7. set the SPRAY_PUMP_RATE to the value the pump should servo should move to when the vehicle is travelling 1m/s expressed as a percentage (i.e. 0 ~ 100) of the full servo range.  I.e. 0 = the pump will not operate, 100 = maximum speed at 1m/s.  50 = 1/2 speed at 1m/s, full speed at 2m/s
-        8. set the SPRAY_PUMP_MIN to the minimum value that the pump servo should move to while engaged expressed as a percentage (i.e. 0 ~ 100) of the full servo range
-        9. set the SPRAY_SPEED_MIN to the minimum speed (in cm/s) the vehicle should be moving at before the pump and sprayer are turned on.  0 will mean the pump and spinner will always be on when the system is enabled with ch7/ch8 switch
+        - set CH7_OPT or CH8_OPT parameter to 15 to allow turning the sprayer on/off from one of these channels
+        - set RC10_FUNCTION to 22 to enable the servo output controlling the pump speed on servo-out 10
+        - set RC11_FUNCTION to 23 to enable the servo output controlling the spinner on servo-out 11
+        - ensure the RC10_MIN, RC10_MAX, RC11_MIN, RC11_MAX accurately hold the min and maximum servo values you could possibly output to the pump and spinner
+        - set the SPRAY_SPINNER to the pwm value the spinner should spin at when on
+        - set the SPRAY_PUMP_RATE to the value the pump servo should move to when the vehicle is travelling 1m/s expressed as a percentage (i.e. 0 ~ 100) of the full servo range.  I.e. 0 = the pump will not operate, 100 = maximum speed at 1m/s.  50 = 1/2 speed at 1m/s, full speed at 2m/s
+        - set the SPRAY_PUMP_MIN to the minimum value that the pump servo should move to while engaged expressed as a percentage (i.e. 0 ~ 100) of the full servo range
+        - set the SPRAY_SPEED_MIN to the minimum speed (in cm/s) the vehicle should be moving at before the pump and sprayer are turned on.  0 will mean the pump and spinner will always be on when the system is enabled with ch7/ch8 switch
 **/
 #pragma once