SRV_Channels: added SRV_Channels::enable_by_mask()

libraries/SRV_Channel/SRV_Channel.h

@@ -321,6 +321,9 @@ public:
     // assign and enable auxiliary channels
     static void enable_aux_servos(void);
 
+    // enable channels by mask
+    static void enable_by_mask(uint16_t mask);
+    
     // return the current function for a channel
     static SRV_Channel::Aux_servo_function_t channel_function(uint8_t channel);
 

libraries/SRV_Channel/SRV_Channel_aux.cpp

@@ -161,6 +161,16 @@ void SRV_Channels::enable_aux_servos()
     }
 }
 
+/// enable output channels using a channel mask
+void SRV_Channels::enable_by_mask(uint16_t mask)
+{
+    for (uint8_t i = 0; i < 16; i++) {
+        if (mask & (1U<<i)) {
+            hal.rcout->enable_ch(i);
+        }
+    }
+}
+
 /*
   set radio_out for all channels matching the given function type
  */