AP_Frsky_Telem: make get_telem_data() static

auto-create the object when it is needed for FPort

libraries/AP_Frsky_Telem/AP_Frsky_Telem.cpp

@@ -39,8 +39,9 @@ extern const AP_HAL::HAL& hal;
 
 AP_Frsky_Telem *AP_Frsky_Telem::singleton;
 
-AP_Frsky_Telem::AP_Frsky_Telem(void) :
-  _statustext_queue(FRSKY_TELEM_PAYLOAD_STATUS_CAPACITY)
+AP_Frsky_Telem::AP_Frsky_Telem(bool _external_data) :
+    _statustext_queue(FRSKY_TELEM_PAYLOAD_STATUS_CAPACITY),
+    use_external_data(_external_data)
 {
     singleton = this;
 }
@@ -97,17 +98,6 @@ bool AP_Frsky_Telem::init()
     } else if ((_port = serial_manager.find_serial(AP_SerialManager::SerialProtocol_FrSky_SPort_Passthrough, 0))) {
         _protocol = AP_SerialManager::SerialProtocol_FrSky_SPort_Passthrough; // FrSky SPort and SPort Passthrough (OpenTX) protocols (X-receivers)
         setup_passthrough();
-    } else if ((_port = serial_manager.find_serial(AP_SerialManager::SerialProtocol_RCIN, 0))) {
-        _protocol = AP_SerialManager::SerialProtocol_RCIN; // FrSky SPort over FPort
-        setup_passthrough();
-    }
-
-    if (_protocol == AP_SerialManager::SerialProtocol_RCIN) {
-        use_external_data = true;
-        setup_passthrough();
-        // we don't setup the thread, as output is driven by the AP_RCProtocol library
-        // calling get_telem_data();
-        return true;
     }
 
     if (_port != nullptr) {
@@ -1101,12 +1091,8 @@ uint32_t AP_Frsky_Telem::sensor_status_flags() const
 /*
   fetch Sport data for an external transport, such as FPort
  */
-bool AP_Frsky_Telem::get_telem_data(uint8_t &frame, uint16_t &appid, uint32_t &data)
+bool AP_Frsky_Telem::_get_telem_data(uint8_t &frame, uint16_t &appid, uint32_t &data)
 {
-    if (!use_external_data) {
-        // not initialised for external data
-        return false;
-    }
     passthrough_wfq_adaptive_scheduler(0);
     if (!external_data.pending) {
         return false;
@@ -1118,6 +1104,22 @@ bool AP_Frsky_Telem::get_telem_data(uint8_t &frame, uint16_t &appid, uint32_t &d
     return true;
 }
 
+/*
+  fetch Sport data for an external transport, such as FPort
+ */
+bool AP_Frsky_Telem::get_telem_data(uint8_t &frame, uint16_t &appid, uint32_t &data)
+{
+    if (!singleton && !hal.util->get_soft_armed()) {
+        // if telem data is requested when we are disarmed and don't
+        // yet have a AP_Frsky_Telem object then try to allocate one
+        new AP_Frsky_Telem(true);
+    }
+    if (!singleton) {
+        return false;
+    }
+    return singleton->_get_telem_data(frame, appid, data);
+}
+
 namespace AP {
     AP_Frsky_Telem *frsky_telem() {
         return AP_Frsky_Telem::get_singleton();

libraries/AP_Frsky_Telem/AP_Frsky_Telem.h

@@ -112,7 +112,7 @@ for FrSky SPort Passthrough
 
 class AP_Frsky_Telem {
 public:
-    AP_Frsky_Telem();
+    AP_Frsky_Telem(bool external_data=false);
 
     ~AP_Frsky_Telem();
 
@@ -137,7 +137,7 @@ public:
     }
 
     // get next telemetry data for external consumers of SPort data
-    bool get_telem_data(uint8_t &frame, uint16_t &appid, uint32_t &data);
+    static bool get_telem_data(uint8_t &frame, uint16_t &appid, uint32_t &data);
 
 private:
     AP_HAL::UARTDriver *_port;                  // UART used to send data to FrSky receiver
@@ -257,6 +257,9 @@ private:
     // setup ready for passthrough operation
     void setup_passthrough(void);
 
+    // get next telemetry data for external consumers of SPort data (internal function)
+    bool _get_telem_data(uint8_t &frame, uint16_t &appid, uint32_t &data);
+    
     static AP_Frsky_Telem *singleton;
 
     // use_external_data is set when this library will