Rudder Feedback Servo

The rudder current draw information is sent back to the hand held transmitter and the pictured servo responds accordingly.

If you look closely at this picture you see that the servo glued to the stick mechanism had a small spring at attached at the end of the servo arm.

That is a tension spring used to center the stick. The servo can loosen or tighten the spring. As higher current draw numbers are received the servo pulls harder on the spring. With lower number the spring is loosened.

Ardino Ammeter

I'm on a little tangent from the original arduskipper project.

Senario: When you are sailing a real sailboat and you are the skipper you have a hand on the tiller. With that feel you can tell how much resistance the rudder producing as the boat moves through the water. To keep the boat on course sometimes you feel a considerable resistance as you push the tiller to one side.

As a radio control sailor you don't feel any of that. There is no feedback system to tell you if your just dragging your rudder sideways though the water until you see that your boat is slowing down.

So, what you see in the picture is a resistor in parallel with the servo power lines. The arduino analog input is measuring the voltage across the resistor. So basically its an ammeter measuring the servo current draw.

The relative current number is sent back to the hand held transmitter.