AP_Baro: added dummy driver

useful for board bringup

libraries/AP_Baro/AP_Baro.cpp

@@ -42,6 +42,7 @@
 #include "AP_Baro_FBM320.h"
 #include "AP_Baro_DPS280.h"
 #include "AP_Baro_BMP388.h"
+#include "AP_Baro_Dummy.h"
 #if HAL_WITH_UAVCAN
 #include "AP_Baro_UAVCAN.h"
 #endif

libraries/AP_Baro/AP_Baro_Dummy.cpp

@@ -0,0 +1,13 @@
+#include "AP_Baro_Dummy.h"
+
+AP_Baro_Dummy::AP_Baro_Dummy(AP_Baro &baro) :
+    AP_Baro_Backend(baro)
+{
+    _instance = _frontend.register_sensor();
+}
+
+// Read the sensor
+void AP_Baro_Dummy::update(void)
+{
+    _copy_to_frontend(0, 91300, 21);
+}

libraries/AP_Baro/AP_Baro_Dummy.h

@@ -0,0 +1,20 @@
+/*
+  dummy backend barometer. Used during board bringup. Selected using
+  BARO line in hwdef.dat
+ */
+#pragma once
+
+#include "AP_Baro_Backend.h"
+
+class AP_Baro_Dummy : public AP_Baro_Backend
+{
+public:
+    AP_Baro_Dummy(AP_Baro &baro);
+    void update(void) override;
+    static AP_Baro_Backend *probe(AP_Baro &baro) {
+        return new AP_Baro_Dummy(baro);
+    }
+
+private:
+    uint8_t _instance;
+};