Rudder Servo

[JCampana]

You are absolutely correct. Adding just a rudder allows you to give your glider the ability to steer, but without input you are still steering blind. A compass/magnetometer is one way to feed direction to your glider to get it to go in a straight line. For example, we have used Adafruit BNO055 9DOF IMU in one of our gliders.
Another way to feed direction information to you glider could be to use light sensors and make your glider follow a bright light or a certain color of light.
You could also use a sound sensor to listen for simple commands, directing your glider to turn either right, left, or straight. Some students we have worked with have used the SparkFun Sound Detector to do something similar.

[mpustie]

How does the rudder know in what angle to move without a compass? Let's say that the glider is to traverse a pool due north in the quickest time. Using a magnetic compass which would sense how much the glider was deviating from the north direction in degrees and then compensate by moving the rudder appropriately makes sense to me. Isn't some sort of electronic sensor required here? What am I missing? Thanks in advance for any insight!

[Chris_nunes]

I am glad it was helpful, and its not a dumb question!
When placing the rudder.write(val) command into the seaGlide code, be careful to make sure it is called during the rise, dive, and pause functions otherwise it will be ignored while the void loop() is executing the other functions. I suggest making your own function like "void steer()" and call it in all of the functions where the Arduino spends most of its time (mostly while loops).
The servo does tend to twitch right now due to some timer conflicts with the IRlibrary, but it should still respond. A good way to debug this is to Serial.println(theValue) that you are writing to the servo and make sure the code is doing what you expect. Some times something as simple as 1/2 can equal zero in micro controller language due to the overly specific nature of fixed point math.(eg. 1/2=0 and 1.0/2.0=0.5)

Sorry for the slow response, I hope it helps!

[Will Lamborn]

This was so helpful! thank you so much.

Have a probably dumb question but here I go. I have tested the rudder servo with a servo sweep and it works, then I tested the basic seaglide code and it works. My problem is when I try to place the rudder servo code into the seaglide code, the rudder servo won't run until the plunger waits to change directions. Even then, the rudder servo kind of just fidgets in place instead of actually turning. I don't know how to fix this.

please help

[Chris_nunes]

if you attach a tail servo, you probably want to connect it to your rudder.
This part can help attach your existing rudder to the servo horn.

[Chris_nunes]

Want your glider to navigate to victory? hopefully this will help. Attached are the early instructions for how to use a rudder servo on your glider.
PLEASE ASK QUESTIONS!!
If this document is not perfectly clear to you, that is fine, post a question and let us all grow our knowledge together.
Remember that these are advanced modules and not the well tested solutions in the rest of the kit so there will probably be bugs and surprises. PLEASE SHARE THEM!!