Hello,
im working on my senior project and we want to connect an arduino to a servo motor. first we need this servo to be able to detect angle(using it in tires)..
Thanks a lot 
AWF
To detect the angle, do you mean a feedback signal ?
The Servo motor library can be used with any Arduino board as far as I know.
But the servo motors need a seperate power supply. The 5V pin of the Arduino can not power a servo motor.
What kind of servo motor are you talking about ? Small servo motors, like the one used in RC cars ? or big industrial servo motors ?
AWF7:
we need this servo to be able to detect angle(using it in tires)..
Can you expand on this? If you're talking about small hobby servos, they have an internal position feedback controller and simply go to whatever position you command. If that's what you're dealing with, detecting the angle externally doesn't make a lot of sense since it will simply be what you have commanded. Perhaps you have something else in mind, in which case you need to explain what.
actually i mean that if the command did not take place..
it means if there was a command that tells to rotate and then the command corrupted i want to be sure if the command was done or not..
I am searching for a servo that does that( that does make sure that the tire rotated 15 degree as the command wanted)
i want the servo to be for a prototype car(not a big motor and also not the very small motor)
Thanks
i used the servo library:
and here you can find a servo-example:
it should work fine without any problems. so it worked for me! 
good luck!
A servo can be modified so that the servo pot wiper voltage can be measured if desired, which would be an indicator of its current physical position.
AWF7:
actually i mean that if the command did not take place..
it means if there was a command that tells to rotate and then the command corrupted i want to be sure if the command was done or not..
Well now, we are still not sure at what level you want this verification to occur.
If you are referring to whether the Arduino itself correctly sends the control signal to the servo, then that is a "fox guarding the chickens" scenario - if the code in the Arduino is not executing, then everything is lost; you may as well "pack up and go home" - it either works or it does not.
If you mean you want to determine whether the servo has moved to the correct position for what it has been commanded, than that is actually quite simple - you just use some sort of sensor to monitor the current it is drawing. If it has not moved to the correct position, it will be powering its motor fully in an effort to do so and there will be significant current drawn, the current will be much reduced when it has found its required position.
Thanks a lot
But i heard that a motor have this option in it( test if the tires rotated) so i asked if anyone knows anything about this motor
Is there suvh thing? Or should i use an ecoder? Or a sensor?
Thank youu
AWF7:
actually i mean that if the command did not take place..
it means if there was a command that tells to rotate and then the command corrupted i want to be sure if the command was done or not..I am searching for a servo that does that( that does make sure that the tire rotated 15 degree as the command wanted)
i want the servo to be for a prototype car(not a big motor and also not the very small motor)
If you're using a servo as a drive motor, I suspect what you're using is actually a 'continuous rotation' servo which has the position feedback mechanism broken so that in effect it just works as a variable speed motor. In this case you can tell what speed the servo has been requested to move at, but you can't infer what speed it has actually moved at and so you can't know the exact angle that it has moved by. In order to know that you would need to add an extra sensor such as a rotary encoder. Since you (presumably) know the direction that the wheel is intended to be moving, this could be as simple as a single toothed wheel and pickup or a striped tape and optical sensor and needn't be a full quadrature encoder.