enter image description here Here's an image of my circuit diagram. There are 8 9g servos connected to the arduino gpio pins. The servos have an external power supply of 3 volts (may vary depending on the voltage requirement of the 9g) and the arduino is powered through an adaptor. Is this a convenient way of doing it? Have I gone wrong somewhere? I am new to circuit designing so I am confused.

Thank you! :)

  • That diagram is impossible to read. Redraw it so that wires dink mask other wires. Keep wires to horizontal or vertical with 90 degree bends only.
    – Majenko
    Nov 29, 2016 at 9:37
  • @Majenko Apologies. I've edited the post with a breadboard design. I'll re-draw the whole thing in case even this one is difficult. :)
    – user28637
    Nov 29, 2016 at 12:09

1 Answer 1


These servo are driven off of a PWM signal. This means that you need to connect the control line to a pin that is capable of PWM.

For the Uno it is D3, D5, D6, D9, D10 & D11.

Unfortunately there are only 6 PWM capable pins and you need 8.

You could consider bit banging the PWM for the 7th & 8th motor.

Alternatively, if two of the motors are to be driven exactly the same, they could share the PWM control line between them.

If you need to control each motor separately (without bit banging) you may have to upgrade to a Arduino Mega 2560. The Mega has 15 PWM channels.

An Arduino example of controlling the servo motor can be found in the Libraries section of the Arduino website. https://www.arduino.cc/en/Tutorial/Knob

  • Thanks a lot for your insight! :) I want all the motors to work independently therefore I will need another pwm connection. But once I connect all the control lines to the pwm, would this circuit diagram work?
    – user28637
    Nov 29, 2016 at 6:13
  • Providing you do it right, yes.
    – sa_leinad
    Nov 29, 2016 at 7:12
  • Edited my answer to suggest using an Arduino Mega 2560, which has 15 PWM channels. Or you could even use 2 Arduino Unos.
    – sa_leinad
    Nov 29, 2016 at 7:23
  • Yeah, I'll consider using a 2560. I could always do with more channels. haha. Thanks again! :)
    – user28637
    Nov 29, 2016 at 8:18
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