AP_RangeFinder: move update function to serial base class

libraries/AP_RangeFinder/AP_RangeFinder_BLPing.h

@@ -27,7 +27,7 @@ private:
     void send_message(uint16_t msgid, const uint8_t *payload, uint16_t payload_len);
 
     // read a distance from the sensor
-    bool get_reading(uint16_t &reading_cm);
+    bool get_reading(uint16_t &reading_cm) override;
 
     // process one byte received on serial port
     // returns true if a distance message has been successfully parsed

libraries/AP_RangeFinder/AP_RangeFinder_Benewake.h

@@ -26,7 +26,7 @@ private:
 
     // get a reading
     // distance returned in reading_cm
-    bool get_reading(uint16_t &reading_cm);
+    bool get_reading(uint16_t &reading_cm) override;
 
     uint8_t linebuf[10];
     uint8_t linebuf_len;

libraries/AP_RangeFinder/AP_RangeFinder_Lanbao.h

@@ -26,7 +26,7 @@ protected:
 
 private:
     // get a reading
-    bool get_reading(uint16_t &reading_cm);
+    bool get_reading(uint16_t &reading_cm) override;
 
     uint8_t buf[6];
     uint8_t buf_len = 0;

libraries/AP_RangeFinder/AP_RangeFinder_LeddarOne.h

@@ -55,7 +55,7 @@ protected:
 
 private:
     // get a reading
-    bool get_reading(uint16_t &reading_cm);
+    bool get_reading(uint16_t &reading_cm) override;
 
     // CRC16
     bool CRC16(uint8_t *aBuffer, uint8_t aLength, bool aCheck);

libraries/AP_RangeFinder/AP_RangeFinder_LightWareSerial.h

@@ -21,7 +21,7 @@ protected:
 
 private:
     // get a reading
-    bool get_reading(uint16_t &reading_cm);
+    bool get_reading(uint16_t &reading_cm) override;
 
     char linebuf[10];
     uint8_t linebuf_len = 0;

libraries/AP_RangeFinder/AP_RangeFinder_MaxsonarSerialLV.h

@@ -21,7 +21,7 @@ protected:
 
 private:
     // get a reading
-    bool get_reading(uint16_t &reading_cm);
+    bool get_reading(uint16_t &reading_cm) override;
 
     char linebuf[10];
     uint8_t linebuf_len = 0;

libraries/AP_RangeFinder/AP_RangeFinder_NMEA.h

@@ -44,7 +44,7 @@ private:
     };
 
     // get a reading
-    bool get_reading(uint16_t &reading_cm);
+    bool get_reading(uint16_t &reading_cm) override;
 
     // add a single character to the buffer and attempt to decode
     // returns true if a complete sentence was successfully decoded

libraries/AP_RangeFinder/AP_RangeFinder_Wasp.h

@@ -47,7 +47,7 @@ private:
 
     wasp_configuration_stage configuration_state = WASP_CFG_PROTOCOL;
 
-    bool get_reading(uint16_t &reading_cm);
+    bool get_reading(uint16_t &reading_cm) override;
 
     void parse_response(void);
 

libraries/AP_RangeFinder/AP_RangeFinder_uLanding.h

@@ -32,7 +32,7 @@ private:
     bool detect_version(void);
 
     // get a reading
-    bool get_reading(uint16_t &reading_cm);
+    bool get_reading(uint16_t &reading_cm) override;
 
     uint8_t  _linebuf[6];
     uint8_t  _linebuf_len;

libraries/AP_RangeFinder/RangeFinder_Backend_Serial.cpp

@@ -51,3 +51,18 @@ bool AP_RangeFinder_Backend_Serial::detect(uint8_t serial_instance)
 {
     return AP::serialmanager().find_serial(AP_SerialManager::SerialProtocol_Rangefinder, serial_instance) != nullptr;
 }
+
+
+/*
+   update the state of the sensor
+*/
+void AP_RangeFinder_Backend_Serial::update(void)
+{
+    if (get_reading(state.distance_cm)) {
+        // update range_valid state based on distance measured
+        state.last_reading_ms = AP_HAL::millis();
+        update_status();
+    } else if (AP_HAL::millis() - state.last_reading_ms > 200) {
+        set_status(RangeFinder::Status::NoData);
+    }
+}

libraries/AP_RangeFinder/RangeFinder_Backend_Serial.h

@@ -23,4 +23,11 @@ protected:
     virtual uint16_t tx_bufsize() const { return 0; }
 
     AP_HAL::UARTDriver *uart = nullptr;
+
+    // update state; not all backends call this!
+    virtual void update(void) override;
+
+    // it is essential that anyone relying on the base-class update to
+    // implement this:
+    virtual bool get_reading(uint16_t &reading_cm) { return 0; }
 };