Power servo trough Nanos USB?

Hi!

I´m about to order 5 Arduino Nanos.
I will use a 5VDC 2A phonecharger to power the Arduino Nano trought the USB.

Will I be able to power bigger servos via Nano connected to the USB?
With bigger servo I mean this one:

Thanks in advance!

No.
The Nano has a backflow protection diode between USB and the 5volt pin.
You will fry that schottky diode if you try to draw more than 500mA from the Nano's 5volt 4.6volt rail.
Leo..

How can I solve this?
Cutting off the USB socket and put the positive cable into the breadboard so it's feeding the Nanos 5V pin and the Servo?
Then common ground for the negative and servos negative?

You could solder a wire to the point before the diode.
And power the servo from that wire.
There are many different Nano board layouts. Post a link to the one you have ordered.
Ground is not the problem. Connect as normal.
Leo..

Wawa:
You could solder a wire to the point before the diode.
And power the servo from that wire.
There are many different Nano board layouts. Post a link to the one you have ordered.
Ground is not the problem. Connect as normal.
Leo..

Thanks for the answer.
That sounds great!
I brought these: (if you can´t access the link, copy-paste it)

EDIT:
Why not use pin 27 (5V regulated) on the nano and the servo on same rail on the breadboard?
I´m not the greatest to solder.

Don't know that version of the Nano, but the diode seems to be right under the USB socket, marked B2.
It seems that the raw USB supply is available on the diode pin closest to the edge of the board.
I'm always reluctant to power an Arduino and a motor from the same supply.
If you have problems (Arduino restarting etc.), add a 1000uF cap from +servo (diode point) to ground.
Leo..

You can get those "wall-wart" chargers with multiple outlets, use 1 for Arduino, and 1 (or more) for servos.

https://www.amazon.com/Honest-Charger-Adapter-Portable-Battery/dp/B01FJP2MUQ/ref=sr_1_19?s=electronics&ie=UTF8&qid=1476256405&sr=1-19&keywords=usb%2Bpower%2Bsupply&th=1

Thanks for the ideas, but then I will have two cords running to my little box, and I want to have the project as descreet as possible. Also I have a nano. :slight_smile:

Why is it not a good idea to have the power supply on the pin 27 and powering the servo on the same rail on the breadboard? If the input is in a "middle" hole, the nano on one side, and servo in the other?
Not questioning, just curious.

istvanuino:
Why is it not a good idea to have the power supply on the pin 27 and powering the servo on the same rail on the breadboard? If the input is in a "middle" hole, the nano on one side, and servo in the other?
Not questioning, just curious.

No idea what you mean with pin27, so the rest also doesn't make sense.

Just plug the USB lead into that power supply you linked to in post#0.
Connect servo ground to a ground pin of the Nano, control pin to the right output pin, and servo power to that wire I told you to solder on.
Leo..

Wawa:
No idea what you mean with pin27, so the rest also doesn't make sense.

Just plug the USB lead into that power supply you linked to in post#0.
Connect servo ground to a ground pin of the Nano, control pin to the right output pin, and servo power to that wire I told you to solder on.
Leo..

Please take a look at this link.
There you can read:
"Power:
The Arduino Nano can be powered via the Mini-B USB connection, 6-20V unregulated external power supply (pin 30),
or 5V regulated external power supply (pin 27). The power source is automatically selected to the highest voltage source."

I connect the power supply 5VDC to the same rail on the breadboard as the pint 27 on the Nano, then the +5VDC Servo on the same rail on the breadboard.
I try to illustrate what I mean below:
Dots represent the breadboard.

NANO
Pin 24 I-
Pin 25 I-
Pin 26 I-
Pin 27 I-....-Servo +5VDC
Pin 28 I- I
I
I
I
I
5VDC input

Sure, you can supply the Nano with 5volt on the 5volt pin, and power the servo from the same 5volt.

But that means you have to cut a USB lead if you want to use the supply you linked to in post#0.
Leo..

Wawa:
Sure, you can supply the Nano with 5volt on the 5volt pin, and power the servo from the same 5volt.

But that means you have to cut a USB lead if you want to use the supply you linked to in post#0.
Leo..

Yes, I wrote that a few posts before asking about cutting the USB, but then you told me not to feed the Servo and the Nano.

So, my question is, may the Nano behave the same (maybe reset and so on) if I connect as I told you above? :slight_smile:

I think you asked if you could power the Nano through the USB socket (with the USB supply and a USB cable).
And power the servo from the 5volt pin of the Nano.
That is not possible.
Leo..

If you don’t need USB communication, take a USB power cable like the one I linked, cut the barrel connector off, connect the + wire to breadboard + bus, - wire to - bus put a jumper from + bus to Nano 5V pin and a jumper from - bus to Nano GND pin, you can still plug in the USB cable from the computer to communicate but you may get a reset.
Make sure the 5V supply is well regulated.

Or keep the barrel connector and use one of these:
https://www.sparkfun.com/search/results?term=barrel+connector

Untitled.JPG

Wawa:
I think you asked if you could power the Nano through the USB socket (with the USB supply and a USB cable).
And power the servo from the 5volt pin of the Nano.
That is not possible.
Leo…

Yes. My original question was that.
But the thread envolved into how to power the arduino alternativley.
That´s why I`m asking this about using the same rail for both Pin 27 and Servo +5VDC -IF IT´S POSSIBLE?
I have ordered this breadboard to have smaler projectboxes:

outsider:
If you don’t need USB communication, take a USB power cable like the one I linked, cut the barrel connector off, connect the + wire to breadboard + bus, - wire to - bus put a jumper from + bus to Nano 5V pin and a jumper from - bus to Nano GND pin, you can still plug in the USB cable from the computer to communicate but you may get a reset.
Make sure the 5V supply is well regulated.

Or keep the barrel connector and use one of these:
https://www.sparkfun.com/search/results?term=barrel+connector

Untitled.JPG

Thanks for the tips.
But I find that to be alot of “more work” for nothing.
Fewer connections = lesser chance for problem. (I work as a automation electrician on a big maintenance department).
One rail for powering the nano and the Servos +5VDC -IF IT´S POSSIBLE?

istvanuino:
One rail for powering the nano and the Servos +5VDC -IF IT´S POSSIBLE?

This has been answered a few times already.
Tell us what part of the answers you don't understand.

The big question is how you are going to connect that 5volt/2Amp supply with USB socket from post#0.

  1. Plugging in the USB lead that you already have.
    And adding/soldering one short wire to that diode.

  2. Or the hard(er) way, by cutting/modding USB and/or power leads.
    Leo..

Wawa:
This has been answered a few times already.
Tell us what part of the answers you don't understand.

The big question is how you are going to connect that 5volt/2Amp supply with USB socket from post#0.

  1. Plugging in the USB lead that you already have.
    And adding/soldering one short wire to that diode.

  2. Or the hard(er) way, by cutting/modding USB and/or power leads.
    Leo..

Okey, I´ll try to solder the nano.
But If I solder the B2 diode closest to the edge how do I know it will work? I mean it will give currents over 500mA? I don´t fry the Nano?

If you solder the diode, the only danger is frying a trace or two on the board if you draw too much power.
You could leave the diode alone and just add a jumper between the USB pin and the header pin you want to use.

CrossRoads:
If you solder the diode, the only danger is frying a trace or two on the board if you draw too much power.
You could leave the diode alone and just add a jumper between the USB pin and the header pin you want to use.

No Eagle files of that Nano, but it seems that diode is the closest point to the power pin of the USB socket.
It's mounted right underneathe the USB socket.
OP is going to draw ~1Amp max (servo), and use a 5volt/2Amp supply.
I doubt that a track designed for .5Amp is going to vaporize with the ~1Amp of the servo.

But OP, if you want to play safe, use two supplies.
Leo..

About this Amp draw I "googeld" the two servos I will use.

The first one: (I think It will never use more than 500mA, so I will use it from USB power).

The Second one I´m a bit worried about.
According to these charts It draw 1.8 A with one controller, the rest under 500mA. Now what? :slight_smile:
http://www.phidgets.com/products.php?product_id=3212