Arduino Forum

Topics => Robotics => Topic started by: DrBwts on Dec 08, 2018, 05:59 pm

Title: Intermittent jittering servo
Post by: DrBwts on Dec 08, 2018, 05:59 pm
I'm controlling a Hitech servo from a 10k slider via a Nano. For a while the motion tracks the slider position even when moved quickly.

Then, for no reason I can find, it will stop following smoothly & only move in jittery steps & then move as expected again!

YouTube vid of the behaviour (https://youtu.be/qBQzK6pM0r8)

Anyone seen this kinda thing before?
Title: Re: Intermittent jittering servo
Post by: slipstick on Dec 08, 2018, 06:20 pm
I can see almost nothing in that vid, certainly not what any slider is doing.

But jittering/uneven movement problems are often caused by powering the servo via the Arduino 5V pin or a weak battery or by connecting it via a breadboard or similar high resistance connections. Or sometimes by bad code.

So some details of the servo, power, circuit diagram and the code you're using might help.

Steve
Title: Re: Intermittent jittering servo
Post by: DrBwts on Dec 08, 2018, 07:45 pm
Yeah just rewatched it, sorry about the lighting in the vid.

The circuit is the same as on the examples page for the servo pot example built on a bread board.

The servos power doesnt come from the Nano but does share the same power supply.

The servo is a Hitec HS-625MG
Title: Re: Intermittent jittering servo
Post by: jremington on Dec 08, 2018, 11:33 pm
The power supply must be able to provide at least 2.5 Amperes (the stall current), or the servo will misbehave.
Title: Re: Intermittent jittering servo
Post by: DrBwts on Dec 09, 2018, 11:30 am
Just changed the power supply & now its all working thankyou for your help.