Capacitors - Scopes - Beginner

[tvl]

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[Johncanfield]

What are you using for a voltage source?

[MavMitchell]

Is this noise matching the pulses on the control wire? Is this noise visible all the time, or only while the servo is in motion?

[rstofer]

I wouldn't take the servo power from 5V if I could avoid it.  It would be far better to have a separate 6V supply with the ground sides tied together.

If I couldn't do that, I would connect the servo power all the way back at the PSU and nowhere near the CPU.

You can always add more capacitance but you might also look at adding 0.1 ufd ceramic capacitors right at the CPU pins and another very close to the servo.  These smaller capacitors are more effective at eliminating high frequency noise (which I really don't see anyway).

Basically, it seems you have too much resistance in your power source to the servo.  I'm assuming the voltage is sagging.  You really should show a second channel with the servo signal so we can align the supply voltage signal with the servo PWM.  Trigger on the PWM and show a couple of cycles.

In fact, add the second trace first and the post the results.