Analog Servo Confusion. Will This Servo Work?

Hello, I just received in the mail a digital servo and an analog servo of the same size. I got an MG995 and this servo: https://www.amazon.ca/gp/product/B00MPW2N6K/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

After plugging it in and doing the knob code test, the digital mg995 works, but the analog one just makes a tapping noise every second. Using google, I have found sources that say analog works just like digital servos in terms of connection and code (servo library). Such as this post: http://forum.arduino.cc/index.php?topic=21149.0 But I have also found sources (including someone that I know in real life) That said I cannot use the servo because it is analog and I will break it if I try to use it with the arduino.

Who is really correct and how do I get this servo to budge? Is it a power issue? I thought analog servos were supposed to consume less power. I really am lost so may someone please tell me if this particular servo is usable with an arduino before I go about during further testing and getting power supplies. I don't want to risk damaging this motor. Thanks!

Both those servos are standard hobby servos, and they work the same way. There is some confusion as to exactly what "digital" means in this case, but just use the Arduino servo library to control them.

If one of the servos runs up against an end stop, it may not be correctly centered at neutral, or defective.

The knob example shows the servo being powered from the Arduino, which you shouldn't do anyway, since it can't provide enough current.

So should I follow this guy's advice regarding power?

And I will be uploading a video shortly showcasing the issue at hand when not using a proper power source.

Always use a separate power supply for motors and servos. For servos, budget at least one ampere of current per active servo.

Forum members are extremely familiar with the problems of not using a proper motor/servo power supply. We get posts every day from beginners who make that mistake, usually from following a tutorial on Instructables or posted by some other confused beginner.

So would a cable plugged into a 5v 2A brick work if i strip the wire? and here is a hastly done video of the issue: Arduino servo confusion - YouTube

I gave up on the video 40s in, didn't know what any of the wires and caps and resistors were for.

But yes I guess that power supply will be good: make sure to join the -ve of the power /servo to the Arduino.

So would a cable plugged into a 5v 2A brick work if i strip the wire?

That should power two servos. Connect the Arduino ground and the negative lead of the brick together.

So um guys, it wasnt a power issue. I realized that if i turned slowly, at acertain value a to value b, it moves, but anything else it does not read. What does “Required Pulse: 500us-2500us” exactly mean?

Servos operate according to a pulse width scheme. 1500 us pulses correspond typically to the neutral position (0 degrees), 1000 us pulses move the arm about 90 degrees away, etc. Servo control - Wikipedia

I have no idea what you mean by the rest of the post.

Erm My dad just explained it to me. It was along the lines of "Since you are using a pulse method to control the analog servo which uses an analog (smooth) kind of power, it does not work properly. When you go slow, the pulses get wider and sort of replicate the analog power it is supposed to receive, but when you go fast, the frequency or something gets too high for the analog servo to pick up and react." He then said If i really want to use this motor, i would have to get two capacitors and looking at his drawing, it looks like two capacitors surrounding ground which he explained was so that it can spin both ways.

Is this right?

It was never a power issue at all. It was the fact that it was analog. It still turns but only if I turn the knob slowly. Why did so many sources say that analog servos worked pretty much flawlessly just like digital ones? Am I missing something? He also mentioned that 100uf was the way to go for the capacitors. I found this page: https://arduino-info.wikispaces.com/Analog-Output
Is this of any use?

TheStig3136:
Erm My dad just explained it to me. It was along the lines of "Since you are using a pulse method to control the analog servo which uses an analog (smooth) kind of power, it does not work properly. When you go slow, the pulses get wider and sort of replicate the analog power it is supposed to receive, but when you go fast, the frequency or something gets too high for the analog servo to pick up and react." He then said If i really want to use this motor, i would have to get two capacitors and looking at his drawing, it looks like two capacitors surrounding ground which he explained was so that it can spin both ways.

Is this right?

No it's total cr@p.

An analog servo expects a pulse, 1500ms being the nominal middle and 1000 or 2000 being nominally 0 and 180 degrees. The servo library takes care of those pulses given a degree value from you, and the sketch converts your pot value to degrees.

It's my understanding that to the outside world, analog and digital servos are identical: it's inside where it's digital. An analog servo has a potentiometer inside which it uses to measure where it is so it knows if it got where you told it; a digital one presumably does that digitally. But they both need 1000-2000ms pulses to control them.

TheStig3136:
Why did so many sources say that analog servos worked pretty much flawlessly just like digital ones?

I've never used anything but analog servos and they all work as advertised, flawlessly.

And if you continue to power your servo, expecting let's say an Amp or so, from the Arduino, you're going to let the magic smoke out.

Well obviously they aren't identical as I am having issues with it. Everyone just plays the blame game on the power supply and calls it a day. Yet, through my testing, improved power doesn't mean anything. Would you like me to make a new recording of my findings? Sure, you can call that theory wrong, but that really means nothing if the issue is still present.

TheStig3136:
Everyone just plays the blame game on the power supply and calls it a day.

Did you connect the ground of the Arduino to the battery/servo -ve?

TheStig3136:
Well obviously they aren't identical as I am having issues with it.

No they're not identical, since they differ electronically inside. But operationally they're the same: you give it a pulse between nominally 1000 and 2000 ms and voila, it goes somewhere between 0 and 180 degrees, or in the case of a continuous servo, spins in one or other direction at whatever speed.

Yes I did, and I can do it again if you like but it's 5 am right now and I'm only awake because of allergies. Can no one explain why my analog servo only responds to a slow rotation of the knob and not a quick flick? An extremely slow turn of the knob doesn't do much either. And why does my digital servo work when it presumably uses more power due to it being digital and having more cycles or whatever.

TheStig3136:
being digital and having more cycles or whatever.

What does that even mean?

If there is more power consumed by a digital servo due to its electronics as opposed to reading the pot internally, I'd think it would be in the range of a few mA if that. Nothing in the grand scheme of a servo drawing 1000mA or so.

Please post a circuit diagram.

I can only repeat that I've never used anything but analog servos, never even seen or touched a digital one, and they all operate correctly using the servo library with the sweep or knob codes, or home grown code for whatever purpose. (Once they have proper power, that is.) I have loads of oscilliscope evidence that the pulses are from 1000 to 2000, and what's more, repeated by the servo library every 20ms (if my memory serves?) to get a servo to hold position.

TheStig3136:
Yes I did, and I can do it again if you like but it's 5 am right now and I'm only awake because of allergies. Can no one explain why my analog servo only responds to a slow rotation of the knob and not a quick flick? An extremely slow turn of the knob doesn't do much either. And why does my digital servo work when it presumably uses more power due to it being digital and having more cycles or whatever.

Have you looked at the specifications of both servos, particularly the angular speed rating? They
are obviously different between the two servos. Many servos are rated at about 6 rad/s, but higher
performance ones can be two or three times faster (and require more power to operate).