Project 5 - servo chatter

Hardware The Arduino Starter Kit
1

I'm using the parts from the kit and the servo library provided with Arduino software version 1.8.1 for Mac.

With a few exceptions, nearly every angle seems to produce chatter. Zero degrees is silent. At 179 degrees, the servo oscillates several degrees forward and back.

I then wrote a sketch to walk through the angles, forward and back, with various steps and time delays and still have chatter on nearly every angle. The servo provided with the basic kit is a 'Tower Pro Micro Servo 9g (SG90)". Is the issue with the servo or the servo library? A quick search of the net found mostly decent reviews for the servo. Maybe I got a bad servo in my kit?

2

I think the problem is related to relatively 'dirty' power from the Arduino. I added two more 100uF capacitors in front of the servo leads and the chatter reduced greatly. Nice to have a solution. Nicer still if the Projects Book addressed the issue. I plan to try battery power.

Interesting to me is that stepping by 10 using writeMicroseconds, there are many angles that are dead still (as in quiet) and many that still have some chatter. Maybe the best you can expect from a cheap servo?