Robin2:
Tobbera:
When I steer my boat upwind I use the tell tales in the Jib to keep a constant angle to the wind. To feed this info into the Arudino, my idea is to place the wind vane about a meter in front of the Jib, and a meter above the water, to get clear wind.I am familiar with those tell tales - I had forgotten about them and I agree they are very useful, even essential. Unfortunately all they tell you is how well the wind is flowing over the sail. At that point the airflow is significantly affected by the sail and it is anything but "clear wind". If your wind detector is in clear wind in front of the sail it will be just as fickle as at the top of the mast.
Another thing to bear in mind is that the tell-tales are useless if the airflow over the sail stalls - they can't tell you where to steer the boat to get back into the wind. The wind vane could provide that information but probably can't deal with the fine control.
...R
When tacking upwind, tell tales is basically the only input you have when steering the boat. You set the sails, and steer as high as you can by looking at the tell tales. The tell tales shows the flow around the sail, which essentially is the wind direction. The only reason the tell tales indicates lift or heading, is because of change in apparent wind direction, which I hope I can sense with my wind vane in front of the sail. (Yes, the telltales can indicate "wrongly" because of severe boat movement etc, but that's as well actually apparent wind direction that changes.)
Placing the wind vane in front of the tell tales will hopefully give enough input to the autopilot to keep the tell tales "flying". At lest better than I as human can. By placing the wind vane lower down in front of the boat, it will replicate what I see on the tell tales, and not be affected as much by side to side movement as you have in the top of the mast (which can oscillate 2 meters from side to side and upset the vane.)