SRV_Channel: added a SERVO_32_ENABLE parameter

save on param count for most users

libraries/SRV_Channel/SRV_Channel.h

@@ -641,6 +641,9 @@ private:
     AP_Int8 dshot_rate;
     AP_Int8 dshot_esc_type;
     AP_Int32 gpio_mask;
+#if NUM_SERVO_CHANNELS >= 17
+    AP_Int8 enable_32_channels;
+#endif
 
     // return true if passthrough is disabled
     static bool passthrough_disabled(void) {

libraries/SRV_Channel/SRV_Channel_aux.cpp

@@ -76,7 +76,13 @@ void SRV_Channel::output_ch(void)
  */
 void SRV_Channels::output_ch_all(void)
 {
-    for (uint8_t i = 0; i < NUM_SERVO_CHANNELS; i++) {
+    uint8_t max_chan = NUM_SERVO_CHANNELS;
+#if NUM_SERVO_CHANNELS >= 17
+    if (_singleton != nullptr && _singleton->enable_32_channels.get() <= 0) {
+        max_chan = 16;
+    }
+#endif
+    for (uint8_t i = 0; i < max_chan; i++) {
         channels[i].output_ch();
     }
 }

libraries/SRV_Channel/SRV_Channels.cpp

@@ -242,7 +242,16 @@ const AP_Param::GroupInfo SRV_Channels::var_info[] = {
     // @User: Advanced
     // @RebootRequired: True
     AP_GROUPINFO("_GPIO_MASK",  26, SRV_Channels, gpio_mask, 0),
-    
+
+#if (NUM_SERVO_CHANNELS >= 17)
+    // @Param: _32_ENABLE
+    // @DisplayName: Enable outputs 17 to 31
+    // @Description: This allows for up to 32 outputs, enabling parameters for outputs above 16
+    // @User: Advanced
+    // @Values: 0:Disabled,1:Enabled
+    AP_GROUPINFO_FLAGS("_32_ENABLE", 43, SRV_Channels, enable_32_channels, 0, AP_PARAM_FLAG_ENABLE),
+#endif
+
 #if (NUM_SERVO_CHANNELS >= 17)
     // @Group: 17_
     // @Path: SRV_Channel.cpp