AP_Airspeed: Sanity check DLVR raw data before accumulating it

This is intended to help with really bad RF interference flipping bits on the I2C bus which can lead to some intresting results

libraries/AP_Airspeed/AP_Airspeed_DLVR.cpp

@@ -104,7 +104,7 @@ void AP_Airspeed_DLVR::timer()
 
     if ((data >> STATUS_SHIFT)) {
         // anything other then 00 in the status bits is an error
-        Debug("DLVR: Bad status read %d", data >> STATUS_SHIFT);
+        Debug("DLVR: Bad status read %u", (unsigned int)(data >> STATUS_SHIFT));
         return;
     }
 
@@ -112,15 +112,31 @@ void AP_Airspeed_DLVR::timer()
     uint32_t temp_raw = (data >> TEMPERATURE_SHIFT) & TEMPERATURE_MASK;
 
     float press_h2o = 1.25f * 2.0f * range_inH2O * ((pres_raw - DLVR_OFFSET) / DLVR_SCALE);
+
+    if ((press_h2o > range_inH2O) || (press_h2o < -range_inH2O)) {
+        Debug("DLVR: Out of range pressure %f", press_h2o);
+        return;
+    }
+
     float temp = temp_raw * (200.0f / 2047.0f) - 50.0f;
 
     WITH_SEMAPHORE(sem);
 
+    const uint32_t now = AP_HAL::millis();
+
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wfloat-equal" // suppress -Wfloat-equal as we are only worried about the case where we had never read
+    if ((temperature != 0) && (fabsf(temperature - temp) > 10) && ((now - last_sample_time_ms) < 2000)) {
+        Debug("DLVR: Temperature swing %f", temp);
+        return;
+    }
+#pragma GCC diagnostic pop
+
     pressure_sum += INCH_OF_H2O_TO_PASCAL * press_h2o;
     temperature_sum += temp;
     press_count++;
     temp_count++;
-    last_sample_time_ms = AP_HAL::millis();
+    last_sample_time_ms = now;
 }
 
 // return the current differential_pressure in Pascal