AP_OSD: added OSD_TYPE2 param to enable dual OSDs backend support

Co-authored-by:HWurzburg(hurzburg@yahoo.com)

up to 2 OSD instances can run at the same time sharing a single OSD thread

)

libraries/AP_OSD/AP_OSD.cpp

@@ -232,6 +232,15 @@ const AP_Param::GroupInfo AP_OSD::var_info[] = {
     AP_SUBGROUPINFO2(screen[2], "3_", 29, AP_OSD, AP_OSD_Screen),
     AP_SUBGROUPINFO2(screen[3], "4_", 30, AP_OSD, AP_OSD_Screen),
 #endif
+
+    // @Param: _TYPE2
+    // @DisplayName: OSD type 2
+    // @Description: OSD type 2. TXONLY makes the OSD parameter selection available to other modules even if there is no native OSD support on the board, for instance CRSF.
+    // @Values: 0:None,1:MAX7456,2:SITL,3:MSP,4:TXONLY,5:MSP_DISPLAYPORT
+    // @User: Standard
+    // @RebootRequired: True
+    AP_GROUPINFO("_TYPE2", 32, AP_OSD, osd_type2, 0),
+
     AP_GROUPEND
 };
 
@@ -263,7 +272,29 @@ AP_OSD::AP_OSD()
 
 void AP_OSD::init()
 {
-    switch (osd_types(osd_type.get())) {
+    const AP_OSD::osd_types types[OSD_MAX_INSTANCES] = {
+        osd_types(osd_type.get()),
+        osd_types(osd_type2.get())
+    };
+    for (uint8_t instance = 0; instance < OSD_MAX_INSTANCES; instance++) {
+        if (init_backend(types[instance], instance)) {
+            _backend_count++;
+        }
+    }
+    if (_backend_count > 0) {
+        hal.scheduler->thread_create(FUNCTOR_BIND_MEMBER(&AP_OSD::osd_thread, void), "OSD", 1280, AP_HAL::Scheduler::PRIORITY_IO, 1);
+    }
+}
+
+bool AP_OSD::init_backend(const AP_OSD::osd_types type, const uint8_t instance)
+{
+    // check if we can run this backend instance in parallel with backend instance 0
+    if (instance > 0) {
+        if (_backends[0] && !_backends[0]->is_compatible_with_backend_type(type)) {
+            return false;
+        }
+    }
+    switch (type) {
     case OSD_NONE:
     case OSD_TXONLY:
     default:
@@ -276,9 +307,9 @@ void AP_OSD::init()
             break;
         }
 #if HAL_WITH_OSD_BITMAP
-        backend = AP_OSD_MAX7456::probe(*this, std::move(spi_dev));
+        _backends[instance] = AP_OSD_MAX7456::probe(*this, std::move(spi_dev));
 #endif
-        if (backend == nullptr) {
+        if (_backends[instance] == nullptr) {
             break;
         }
         DEV_PRINTF("Started MAX7456 OSD\n");
@@ -288,8 +319,8 @@ void AP_OSD::init()
 
 #ifdef WITH_SITL_OSD
     case OSD_SITL: {
-        backend = AP_OSD_SITL::probe(*this);
+        _backends[instance] = AP_OSD_SITL::probe(*this);
-        if (backend == nullptr) {
+        if (_backends[instance] == nullptr) {
             break;
         }
         DEV_PRINTF("Started SITL OSD\n");
@@ -297,8 +328,8 @@ void AP_OSD::init()
     }
 #endif
     case OSD_MSP: {
-        backend = AP_OSD_MSP::probe(*this);
+        _backends[instance] = AP_OSD_MSP::probe(*this);
-        if (backend == nullptr) {
+        if (_backends[instance] == nullptr) {
             break;
         }
         DEV_PRINTF("Started MSP OSD\n");
@@ -306,8 +337,8 @@ void AP_OSD::init()
     }
 #if HAL_WITH_MSP_DISPLAYPORT
     case OSD_MSP_DISPLAYPORT: {
-        backend = AP_OSD_MSP_DisplayPort::probe(*this);
+        _backends[instance] = AP_OSD_MSP_DisplayPort::probe(*this);
-        if (backend == nullptr) {
+        if (_backends[instance] == nullptr) {
             break;
         }
         DEV_PRINTF("Started MSP DisplayPort OSD\n");
@@ -316,12 +347,12 @@ void AP_OSD::init()
 #endif
     }
 #if OSD_ENABLED
-    if (backend != nullptr) {
+    if (_backends[instance] != nullptr) {
         // populate the fonts lookup table
-        backend->init_symbol_set(AP_OSD_AbstractScreen::symbols_lookup_table, AP_OSD_NUM_SYMBOLS);
+        _backends[instance]->init_symbol_set(AP_OSD_AbstractScreen::symbols_lookup_table, AP_OSD_NUM_SYMBOLS);
-        // create thread as higher priority than IO for all backends
+        return true;
-        hal.scheduler->thread_create(FUNCTOR_BIND_MEMBER(&AP_OSD::osd_thread, void), "OSD", 1280, AP_HAL::Scheduler::PRIORITY_IO, 1);
     }
+    return false;
 #endif
 }
 
@@ -329,30 +360,36 @@ void AP_OSD::init()
 void AP_OSD::osd_thread()
 {
     // initialize thread specific code once
-    backend->osd_thread_run_once();
+    for (uint8_t instance = 0; instance < _backend_count; instance++) {
+        _backends[instance]->osd_thread_run_once();
+    }
+
 
     while (true) {
         hal.scheduler->delay(100);
+        if (!_disable) {
+            update_stats();
+            update_current_screen();
+        }
         update_osd();
     }
 }
 
 void AP_OSD::update_osd()
 {
-    backend->clear();
+    for (uint8_t instance = 0; instance < _backend_count; instance++) {
+        _backends[instance]->clear();
 
         if (!_disable) {
-        update_stats();
+            get_screen(current_screen).set_backend(_backends[instance]);
-        update_current_screen();
-
-        get_screen(current_screen).set_backend(backend);
             // skip drawing for MSP OSD backends to save some resources
-        if (osd_types(osd_type.get()) != OSD_MSP) {
+            if (_backends[instance]->get_backend_type() != OSD_MSP) {
                 get_screen(current_screen).draw();
             }
         }
 
-    backend->flush();
+        _backends[instance]->flush();
+    }
 }
 
 //update maximums and totals
@@ -545,6 +582,28 @@ void AP_OSD::set_nav_info(NavInfo &navinfo)
     // do this without a lock for now
     nav_info = navinfo;
 }
+
+// pre_arm_check - returns true if all pre-takeoff checks have completed successfully
+bool AP_OSD::pre_arm_check(char *failure_msg, const uint8_t failure_msg_len) const
+{
+#if OSD_PARAM_ENABLED
+    // currently in the OSD menu, do not allow arming
+    if (!is_readonly_screen()) {
+        hal.util->snprintf(failure_msg, failure_msg_len, "In OSD menu");
+        return false;
+    }
+#endif  
+
+    //check if second backend was requested by user but not instantiated
+    if (osd_type.get() != OSD_NONE && _backend_count == 1 && osd_type2.get() != OSD_NONE) {
+        hal.util->snprintf(failure_msg, failure_msg_len, "OSD_TYPE2 not compatible with first OSD");
+        return false; 
+    }
+
+    // if we got this far everything must be ok
+    return true;
+}
+
 #endif // OSD_ENABLED
 
 // handle OSD parameter configuration

libraries/AP_OSD/AP_OSD.h

@@ -49,6 +49,7 @@ class AP_MSP;
 #define PARAM_TOKEN_INDEX(token) PARAM_INDEX(AP_Param::get_persistent_key(token.key), token.idx, token.group_element)
 
 #define AP_OSD_NUM_SYMBOLS 91
+#define OSD_MAX_INSTANCES 2
 /*
   class to hold one setting
  */
@@ -506,6 +507,9 @@ public:
         OSD_TXONLY=4,
         OSD_MSP_DISPLAYPORT=5
     };
+
+    bool init_backend(const osd_types type, const uint8_t instance);
+
     enum switch_method {
         TOGGLE=0,
         PWM_RANGE=1,
@@ -513,6 +517,7 @@ public:
     };
 
     AP_Int8 osd_type;
+    AP_Int8 osd_type2; // additional backend active in parallel
     AP_Int8 font_num;
     AP_Int32 options;
 
@@ -649,7 +654,8 @@ private:
 
     StatsInfo _stats;
 #endif
-    AP_OSD_Backend *backend;
+    AP_OSD_Backend *_backends[OSD_MAX_INSTANCES];
+    uint8_t _backend_count;
 
     static AP_OSD *_singleton;
     // multi-thread access support

libraries/AP_OSD/AP_OSD_Backend.h

@@ -55,6 +55,8 @@ public:
 
     // copy the backend specific symbol set to the OSD lookup table
     virtual void init_symbol_set(uint8_t *symbols, const uint8_t size);
+    virtual bool is_compatible_with_backend_type(AP_OSD::osd_types type) const = 0;
+    virtual AP_OSD::osd_types get_backend_type() const = 0;
 
     // called by the OSD thread once
     virtual void osd_thread_run_once() { return; }

libraries/AP_OSD/AP_OSD_MAX7456.h

@@ -41,6 +41,24 @@ public:
     // return a correction factor used to display angles correctly
     float get_aspect_ratio_correction() const override;
 
+    bool is_compatible_with_backend_type(AP_OSD::osd_types type) const override {
+        switch(type) {
+        case AP_OSD::osd_types::OSD_MAX7456:
+        case AP_OSD::osd_types::OSD_SITL:
+            return false;
+        case AP_OSD::osd_types::OSD_NONE:
+        case AP_OSD::osd_types::OSD_TXONLY:
+        case AP_OSD::osd_types::OSD_MSP:
+        case AP_OSD::osd_types::OSD_MSP_DISPLAYPORT:
+            return true;
+        }
+        return false;
+    }
+
+    AP_OSD::osd_types get_backend_type() const override {
+        return AP_OSD::osd_types::OSD_MAX7456;
+    }
+
 private:
 
     //constructor

libraries/AP_OSD/AP_OSD_MSP.h

@@ -19,6 +19,23 @@ public:
     //clear framebuffer
     void clear() override {};
 
+    bool is_compatible_with_backend_type(AP_OSD::osd_types type) const override {
+        switch(type) {
+        case AP_OSD::osd_types::OSD_MSP:
+        case AP_OSD::osd_types::OSD_MSP_DISPLAYPORT:
+            return false;
+        case AP_OSD::osd_types::OSD_NONE:
+        case AP_OSD::osd_types::OSD_TXONLY:
+        case AP_OSD::osd_types::OSD_MAX7456:
+        case AP_OSD::osd_types::OSD_SITL:
+            return true;
+        }
+        return false;
+    }
+
+    AP_OSD::osd_types get_backend_type() const override {
+        return AP_OSD::osd_types::OSD_MSP;
+    }
 private:
     void setup_defaults(void);
 };

libraries/AP_OSD/AP_OSD_MSP_DisplayPort.h

@@ -31,6 +31,23 @@ public:
     // return a correction factor used to display angles correctly
     float get_aspect_ratio_correction() const override;
     
+    bool is_compatible_with_backend_type(AP_OSD::osd_types type) const override {
+        switch(type) {
+        case AP_OSD::osd_types::OSD_MSP:
+        case AP_OSD::osd_types::OSD_MSP_DISPLAYPORT:
+            return false;
+        case AP_OSD::osd_types::OSD_NONE:
+        case AP_OSD::osd_types::OSD_TXONLY:
+        case AP_OSD::osd_types::OSD_MAX7456:
+        case AP_OSD::osd_types::OSD_SITL:
+            return true;
+        }
+        return false;
+    }
+
+    AP_OSD::osd_types get_backend_type() const override {
+        return AP_OSD::osd_types::OSD_MSP_DISPLAYPORT;
+    }
 protected:
     uint8_t format_string_for_osd(char* dst, uint8_t size, bool decimal_packed, const char *fmt, va_list ap) override;
 

libraries/AP_OSD/AP_OSD_ParamScreen.cpp

@@ -595,19 +595,6 @@ void AP_OSD_ParamScreen::draw(void)
 }
 #endif
 
-// pre_arm_check - returns true if all pre-takeoff checks have completed successfully
-bool AP_OSD::pre_arm_check(char *failure_msg, const uint8_t failure_msg_len) const
-{
-    // currently in the OSD menu, do not allow arming
-    if (!is_readonly_screen()) {
-        hal.util->snprintf(failure_msg, failure_msg_len, "In OSD menu");
-        return false;
-    }
-
-    // if we got this far everything must be ok
-    return true;
-}
-
 #endif // OSD_ENABLED
 
 // save all of the parameters

libraries/AP_OSD/AP_OSD_SITL.h

@@ -34,7 +34,7 @@ public:
     //draw given text to framebuffer
     void write(uint8_t x, uint8_t y, const char* text) override;
 
-    //initilize display port and underlying hardware
+    //initialize display port and underlying hardware
     bool init() override;
 
     //flush framebuffer to screen
@@ -43,6 +43,23 @@ public:
     //clear framebuffer
     void clear() override;
 
+    bool is_compatible_with_backend_type(AP_OSD::osd_types type) const override {
+        switch(type) {
+        case AP_OSD::osd_types::OSD_MAX7456:
+        case AP_OSD::osd_types::OSD_SITL:
+            return false;
+        case AP_OSD::osd_types::OSD_NONE:
+        case AP_OSD::osd_types::OSD_TXONLY:
+        case AP_OSD::osd_types::OSD_MSP:
+        case AP_OSD::osd_types::OSD_MSP_DISPLAYPORT:
+            return true;
+        }
+        return false;
+    }
+
+    AP_OSD::osd_types get_backend_type() const override {
+        return AP_OSD::osd_types::OSD_SITL;
+    }
 private:
     //constructor
     AP_OSD_SITL(AP_OSD &osd);