control a continuous rotation servo

Hi,

Is it possible to control a ‘continuous rotation servo’ (parallax) like as a normal servo?
I mean: can this servo stay in different positions?
Normally this servo turns left or right with a specified speed.
A normal servo takes 120 degrees of rotation, so the sensor can’t have a look behind himself.

The project is this:
A heat-sensor turns around and looks at different positions if it is heat or not.
At the heatest position it put a lot of water on it. (like an automatic fire fighter)

Gr.
Johan

You can't tell the continuous servo to go to a particular position, all you can do is turn it both ways with variable speed, and stop it. If you want to stop at a particular position, you'll need some additional hardware such as an encoder, to tell you where the servo has got to.

However, for your project, you might be able to do it. If you can rotate slowly enough to give your heat sensor enough time to get readings with your desired granularity, you could turn continuously looking for readings, perhaps slow even more if you see heat and zero in on it, stop and then release your water.

Thanks for answering. Indeed it's possible to use this servo. I pinned myself too much to the idea of an example of what I read. This is an eyeopener. Thanks.

You could mount two ordinary servos on top of each other to give 360 degree coverage, with slightly fancier software to drive.

(I wish suppliers wouldn’t keep describing these things as “servos” )

There are also servos that can go a full 360 deg. like the this one.

http://www.pololu.com/catalog/product/522

Some call there continuous ones "360 degrees" .

I've gotten the parallax one to move somewhat like a stepper by giving a slight pulse foward (just past neutral) then an even slighter pulse backwards which makes it kind of do a step. By playing around with the pulse timing and doing the loop so many times I was able to pretty much get it to rotate a certain amount. A switch could be used to set zero.

With a little tinkering you can “gear up” the output of a regular servo. Below I used a thread spool on a servo to rotate the shaft in a blind to open/close the blind. Used dental floss wrapped around the spool and the blind shaft. 180 deg servo rotation rotated the shaft ~2.5 times. Servocity has nice gears and such that could be used.