Thank you for bringing this up.
Let’s start analyzing your observations.
When I power up (both on raspberry adapter and GoPiGo battery pack) the servo often takes a small swing. This happens nearly immediately when connecting the power. According to an older thread this is a known issue. I can easily get around this by reseting the servo position with a small script. Just pointing it out for future readers.
This is all normal to happen. Happens with every servo.
A bigger annoyance is the fact that the servo sometimes moves unexpectedly during normal operation of the motors. The behaviour I’m getting sounds similar to the issue reported in this thread. If someone has tips on what to do to improve this situation I would appreciate it.
SoftwareServo library, this means the servo
PWM signals are actually calculated by the
AVR chip that’s on the
SoftwareServo library (which was developed by the
Arduino team) is only using one timer and it was made up so it can control up to
12 servos on any output pin - that’s huge.
But when you win, you also lose something.
So because of this
SoftwareServo library, the timings are not perfect - they do have some jitter.
You can see the
jitter in the following gif I’ve made with the oscilloscope - the vertical line shouldn’t have moved to left and right, but stay in one position - hence the
jitter we’re talking about.
The final conclusion is that, there’s nothing wrong with the
servo, nor the
It’s just the way it works.
Hope I’ve made myself clear. Please tell me if there’s anything else left unclear.