I have a PING Ultrasonic Sensor, Adafruit Absolute Orientation Sensor, and a Continuous rotation servo. All pins are connected to an Arduino Micro. However because the micro only has one 5V output, I used a rail from a breadboard. I connected the + & - leads from all the devices to the rail and then plugged in two leads connecting 5V and GND from the Micro to the rail. My goal was two send power from the Arduino Micro down the rail to all three devices.

I plugged in the Micro, and instead of seeing green lights on the sensor (powered on), the blue light on the Micro turned off and the servo twitched. I have no idea why. Do I need external power for the 5V?

  • Sounds to me like a short or other over-current situation.
    – Majenko
    Commented Jan 15, 2016 at 15:33

1 Answer 1


This sounds like a lot to have connected to the Micro's 5v pin. Without knowing your exact model of servo, I would still believe you are hitting the current limit. Can you try unplugging the servo and see if the circuit functions without the servo? I would power the servo externally with a 5v supply.

  • do you have any recommendations for the power supply? one that i can connect to a breadbooard.
    – Joe salad
    Commented Jan 15, 2016 at 17:31
  • would a 9v battery work?
    – Joe salad
    Commented Jan 15, 2016 at 17:34
  • Personally, I prefer a wall adapter. Any 5V supply that can handle the rated peak load current (plus some for padding) for your servo. I did a quick search on Amazon and I have something like this [supply][1].I also bought some connectors like [this][2]. [1]: amazon.com/gp/product/… [2]: amazon.com/gp/product/…
    – CamK
    Commented Jan 15, 2016 at 17:44
  • I'm definitely not doing these comment hyperlinks right but I'm not sure why..so just ignore that!
    – CamK
    Commented Jan 15, 2016 at 17:45
  • but how would I connect the battery to the breadboard
    – Joe salad
    Commented Jan 15, 2016 at 22:23

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