servo question

[Japper]

Does anyone know of a link to a good tutorial on how to program the hitec HS-322hd servos that came in the 2009 KOP?

I have a side project that I would like to use these on and could not find any useful infomration on Hitec's web site...

thanks

[miniman]

The 2009 WPI libary comes with a set of commands just for servos in labview and I believe there is a class for controlling servos in C/C++. We used the code for labview to control the servos on the robot with great success, for out "hooks of doom"
If you are looking for a way to control them with out the FRC code; the KOP servos take a signal voltage between 0 and 5 volts, the voltage represents the position of the servo, 0 being full in the first direction, 5 being full in the second direction. (Remember the jumper pin if using the digital sidecar. )

[Dad1279]

Originally Posted by miniman

The 2009 WPI libary comes with a set of commands just for servos in labview and I believe there is a class for controlling servos in C/C++. We used the code for labview to control the servos on the robot with great success, for out "hooks of doom"
If you are looking for a way to control them with out the FRC code; the KOP servos take a signal voltage between 0 and 5 volts, the voltage represents the position of the servo, 0 being full in the first direction, 5 being full in the second direction. (Remember the jumper pin if using the digital sidecar. )

They do not work with an analog input(0-5 volts). They expect a digital pulse. PWM = Pulse Width Modulation. I believe 1.5 ms is neutral

The jumper pin on the sidecar provides a constant operating voltage to power the servo.

[MCahoon]

Check http://www.hitecrcd.com/servos/show?name=HS-322HD

Click the "View our servo manual" item. Opens a PDF with pulse voltage and timing specs.

[writchie]

RC servos are normally powered by nicad packs, nominally 7.2 Volts. Most don't work very well at 5V (unless they are 4.8V versions) which is why the sidecar powers them with a fixed 6V supply (the low point for a 6 cell pack).

The PWM signal is a 5Volt pulse. The pulse is nominally between 1.0 and 2.0 ms with 1.5ms representing the center position. The 1.0 and 2.0 ms pulse widths correspond to clockwise and counterclockwise travel limits.

The pulses are usually repeated at 30 - 100 hz. The off time is not critical as long as it is shorter than about 30ms.

If you intend to control your own servos or PWM devices you will get better results with an active buffer to drive the servo cable high and low through a series resistance . Look at the schematics for the sidecar to see how its done well.

[MCahoon]

On re-reading your question: You are interested in a programming tutorial for the servos. What type controller aand what language?

[Japper]

Originally Posted by MCahoon

On re-reading your question: You are interested in a programming tutorial for the servos. What type controller aand what language?

Actually I am planning on using an Arduino to control the servos using it's C complier... I was just looking for information on the Hitec servos and didn't find anything useful on their web site...

Also, I was able to find some information on programming servos in general with the arduino on the arduino forum since posting this to Cheif Delphi...

thanks for the reply!