Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: acar25 on August 26, 2010, 12:05:35 PM

Title: I need some input
Post by: acar25 on August 26, 2010, 12:05:35 PM
I have had an idea of making a robotic arm. A one-jointed arm, that joint being the elbow.

I need to control a servo with a potentiometer. when the potentiometer is turn farthest left (or lowest value) the arm is contracted. When the potentiometer is at the farthest right (or highest value) the arm is extended.

Any advice?
Title: Re: I need some input
Post by: futmacl on August 26, 2010, 12:09:48 PM
Any advice?

On what, specifically? Finding a servo? Building your own servo? Interfacing it to something (if so, to what)?

EDIT: Oh, didn't catch your point - driving a servo based on potentiometer reading, versus just controlling a servo that contains a potentiometer.
Title: Re: I need some input
Post by: Soeren on August 26, 2010, 12:57:53 PM
Hi,

I need to control a servo with a potentiometer. when the potentiometer is turn farthest left (or lowest value) the arm is contracted. When the potentiometer is at the farthest right (or highest value) the arm is extended.

Any advice?
Discard the electronics in the servo (except the H-bridge). Then use a dual comparator chip (eg. LM339) to make a window comparator that compares the two potentiometers (the one in the servo and the external one) and control the bridge from the outputs.
Title: Re: I need some input
Post by: Razor Concepts on August 26, 2010, 07:09:49 PM
Or buy a servo driver for $5