Odd Maestro / Servo behavior

Hi everyone,

I bought a few weeks ago a Micro Maestro 6-Channel USB Servo Controller and an Hitec 645MG servo (for a project I’ll talk about in a few into the Project Category).

The Maestro is connected to a Raspberry Pi3b but receives its power voltage through an individual external adapter (5.8V / 2,4A).

In my project, my servo has 2 positions. One is vertical, one is horizontal. I created these 2 positions using the Provided Control Center.

When I power off my whole installation, the servo is usually stopped while the horn is at horizontal position. Then I usually unplug my adapter from current.

But when I replug the adapter and then power ON my installation, there is a slight move of the servo position, just between horizontal and vertical : this is not wanted at all. It behaves like “being suddenly plugged to the current” makes it receive some unwanted moving signal (?).

If I keep the adapter plugged into the current, even with everything not used, than I can power ON everything and the servo doesn’t move.

Anyone would have an idea as where to start my investigation to stop this strange behavior ?

Thanks in advance :slight_smile:


Hello, Rod.

Does it still happen if you remove the servo from your system and power it separately from the Maestro (or at least while the Maestro is not sending signals to the servo)? From your description, it sounds like the servo is twitching when it is first connected to power, which is fairly common for servos.

If you start sending signals as soon as power is connected, you should be able to minimize the time that the servo is at an undesired position.


Thank you Brandon, this makes sense effectively.

I will do more tests during next weekend and post the results !