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How many volts do two hitec 5055mg servos need, and how do I hook the External battery to an arduino uno? Answered


generally RC servo;s use 5 to 6 volts - The spec sheet for the servo should tell you.

The black/brown wire goes to a common ground with the Ardunio, the red wire to the 5 vold supply - battery or whatever, the white lead (signal) to the Arduino pin.

The supply for the Servo should be seperate from the Arduino supply.

Hi, thanks for your answer but I actually wanted to ask, how to you hook up the external battery to the uno

Hi, this is circuit diagram of how to hook up a servo.

Untitled 123.jpg

can i NOT connect the servo's battery "Ground" wire

to the arduino ground pin?

i have a similar circuit but ...

- 2 servos driven by 6V (a power regulated 9V battery)

- 3 trimpots (10k) & switches

(switches with 10k pulldown resistor each)

once i connect the servo's 6V power ground

to arduino's "gnd" pin i get uncontrollable results

with my potentiometers & switches;

if i disconnect the servo's 6V power ground

from arduino "gnd" pin

the potentiometers & switches work as required ...


You need to have the servo's battery ground wire connected to the arduino ground pin or it will not work, would you be able to send a picture or diagram of how you have wired and i will check it.

hi jack ...

thanks for your reply!

pls. find a sketch of my circuit attached -

i worked on (& corrected) the code meanwhile & it seem to work;

but please have a look - i look forward to any support provided!


Connec the battery to the input jack on the UNO board, that then feeds the 5V regulator on the board DO NOT connect it to the "5v" pins on the shield connectors.