Digital Servos?

[m5burndt]

High all, new to the forum so if you're reading this, thank you.

Our team like many others is looking at using the axis camera to determine the robots position in relation to the goals on the field. For this to work, on of the measurements needed is the precise position of the two servos on the camera gimbal while they point the camera directly at the target. Our programmers will use that data to triangulate the robot's position on the field.

I have been an RC hobbyist for about 8 years now and I know that digital servos hold their position much more firmly and precisely than analog servos, this leads me to believe that it could be to our advantage to use a digital servo in this case. I know that in the RC world, both types can be used with a normal reciever as digital servo's just use a different interface to make 300 adjustments/sec vs. 30adjustments/sec with analog. But i'm not sure that that is true of the digital sidecar. Theoretically, the PWM signal should be the same in both cases

My question is, Has anyone used a Digital servo with the digital sidecar? Are their any problems that you have experienced?

I have been digging in the rules and it seems that the only restrictions on servos are that they are a COTS item and they have a power rating of <4W @6vdc

Any input is appreciated

[RyanN]

From my experience with a Hitec HS-5055MG with a PIC Microcontroller for my senior design project, I can say that they do operate the same for the most part.

With ours, if we get to the outer limits of what a standard servo would take for an input, the digital one will just cut out. We pulled our hair out trying to find our programming bug, when in fact, our code worked perfectly, and it was the servo giving us a fit.

To summarize this, the pulse width for the extremes of this particular digital servo would cause the servo to stop rotating, going into an error state of some sort.

The manual or documentation should show the pulse width limits and the pulse width slot for your particular servo.

[m5burndt]

Interesting, so the digital servo operated fine until it got to the signal extremes? From what i looked up though, that model # servo is on the low end of the digital servo market. We are using 2x Futaba S9257 EP for the Camera (helicioter tail servo, very high precision/speed)

I plugged this servo and an old analog servo into the same channel on a spare RC receiver and they both worked fine.

I guess well just have to try and see, hopefully the programmers will get to it tomorrow.

Thanks

[ajlapp]

I have used them with no issues.

I particularly liked the ability to program the end stops and other internal features.