Powering Pro Mini 5V and a servo with the same external power source

[Zimbu]

Sorry. Yet another one of these questions!

I have read at least 40 different threads and understand I need to use an external power source to power my servo, BUT in my case, I also need to power the Arduino Pro Mini 5V from the same external source.

In a recent thread on a different topic, someone pointed out that I was doing this incorrectly.

Also in another different thread, jremington said "motors introduce noise into shared power supplies and can cause erratic behavior or even damage the Arduino." So now that is a concern of mine as well.

So now I am hoping someone can help me understand how to do it properly. Here's my current wiring:

FYI, my servo needs 5V and between 500-900mA current. Today I measured it at initial power up, and it appears it needs even higher for a very short period, so I am thinking that I will upgrade to a 2 amp AC/DC adaptor instead of the 1 amp adaptor shown in the wiring diagram above.

I appreciate any guidance you can offer!

[jremington]

If this has any hope of working, the power supply MUST be able to supply the stall current of the servo without a significant voltage drop. That might be several amperes.

Given the appropriate power supply, you can still expect problems due to electrical noise. Professional electronic engineers learn to design circuitry to avoid them, using a technique called "power supply decoupling.

Since these are advanced techniques, we advise beginners to use separate power supplies.

[Zimbu]

Well, that's disappointing...

At least thanks for using the words "power decoupling" in your response. I was able to find many different threads here will detailed answers when I searched with those keywords.