Hi Gabe & Costas -
Costas - the GPS antenna is right under the deck, so I don’t think an external GPS antenna would help much. Waiting a minute or two after startup to get GPS lock is important - I’ve not had issues there, with the GPS routinely getting 25-30 satellites locked within 120 seconds. If you are in an area with a lot of radio interference, or heavy cloud cover, GPS signal quality may be reduced.
Gabe, sorry you had some run-away boat issues! The parameter you should checkout that is related to behavior on signal-loss is RC-Failsafe.
FS_THR_ENABLE to “1” to enable this failsafe
FS_ACTION is “1”, the vehicle will RTL to home, if “2” the vehicle will Hold, if “3” or “4” the vehicle will attempt to use SmartRTL but if this mode cannot be engaged the vehicle will RTL or Hold respectively.
I’m glad you recovered the boat without issue!
No calibration of the GPS is necessary. The calibration of the boats motion sensors is required, but this would not affect the position of the vessel on the map, only the behavior of the artificial horizon and compass. I’ve not seen the jump-around issue happen before - any idea how many satellites were locked on when this occurred? This is visible at the top center of QGroundControl, and if clicked, displays the HDOP - or horizontal degree of precision.
When using the vessel with 4G communications, I have the failsafe disabled as it is common to have the occasional communication blip. Sending an E-Stop with no connection to the vehicle is inherently not possible!
The ~200m range for 2.4ghz WiFi omnidirectional antennas is expected. You can improve this by raising the BaseStation antenna height, but you definitely don’t want to “point” the omni-directional antenna at the boat. It is radiating perpendicular to its long axis, so pointing it at the boat minimizes the radio power in the direction of the tip. Overall, the higher the BaseStation the better! Connecting to it with the control computer via WiFi can make using it at extreme heights more convenient.
When it comes to our documentation, we are definitely working to mature and improve things! Thanks so much for the feedback. I would think that for radio range tests, Auto mode is much more suitable than Manual. You would disable the failsafe, and setup a mission that may drive out of range, but will end within range. You then execute the mission, and observe at what distances you lose and re-gain communication. Directional antennas can greatly increase the range, but increasing the height of the antenna on the boat with an extension can also lead to improved performance.
Please keep sharing your experiences!