I am currently doing my first arduino project and i am having trouble finishing it.

I have a 3s lipo battery connected with an esc (120A) that is connected to a motor (270KV). From the esc i am connecting two jumper cables that goes to GND and pin 9. I do not have a jumper cable on the red wire from the ESC.

This is how it looks:

enter image description here

Below you can see a link to a sketch that I found online. The only difference compared to my schematic is that I have an Arduino Uno.

enter image description here

When I insert the battery and switch the ESC to "on" the ESC starts up correctly and the fan starts to go. But the arduino does not get any power. It is still "OFF".

I also noticed that my motor has 4 cables. 3 "bigger" cables that goes to the ESC's 3 big cables. And then a 4th one hanging loose right now because i do not quite know what to do with it. I also noticed there is a hole in the ESC where I can insert this. The hole has 6 "inputs" however where as the loose wire from the motor has 5. Therefor I am a bit concerned if that should be connected there or not.

So to summarize, the problem is that the Arduino does not turn "ON" with my current schematic. Any help, tips is very appreciated!!


3 Answers 3


your arduino is off because you are not powering it. you need to power the arduino.

The battery in the drawing is used exclusively to power the motor. The arduino needs its own separate power supply.

To power the arduino off of a battery you will need something like this.

you can set the output voltage via a usb connection.

If you have additional questions please start a new thread.

  • $\begingroup$ Could I use the middle 5V cable from the ESC to the 5v input of the arduino and power it that way? Or is that dangerous? I have seen some threads where they say you shouldn't do that, but perhaps that is when you are working an BEC which I am not. $\endgroup$ Nov 1, 2016 at 16:28
  • $\begingroup$ Or is my only option to buy a BEC? (If i want to run it without USB connection of course) $\endgroup$ Nov 1, 2016 at 16:36
  • $\begingroup$ Yes, you can powet your Arduino via middle 5V, but check if it really has 5V before you plug it in. $\endgroup$
    – Szczepan
    Nov 1, 2016 at 17:52
  • $\begingroup$ Okok. I bought it from alibaba and of course they have removed the product so I cannot see the specs. Is there any other way to find out? Or do I need to contact the seller? The only thing i know is that it is a 120A Brushless ESC $\endgroup$ Nov 1, 2016 at 18:04
  • 1
    $\begingroup$ I'd check this with multimeter - measure voltage between red and black wire. If it's 6V you should plug it into Vin pin. Otherwise if voltage is about 5V, connect this to your 5V line. $\endgroup$
    – Szczepan
    Nov 2, 2016 at 1:35

You need the power for Arduino Uno which you could get it from the ESC's red wire and connect it with vin pin.

  • 2
    $\begingroup$ Welcome to Robotics booncharat. Thanks for your answer but we are looking for comprehensive answers that provide some explanation and context. Very short answers cannot do this, so please edit your answer to explain why it is right, ideally with citations. Answers that don't include explanations may be removed. $\endgroup$
    – Ben
    Dec 30, 2019 at 19:04

I want to add to @holmeski and his answer.

The ESC, in order to know what voltage the Arduino is sending, needs to know what the reference HIGH voltage is. Usually, in a 3-wire setup as pictured, there is GROUND, HIGH, and SIGNAL. You need to connect an Arduino 5-volt out line to the red line, as well as connect ground and signal the way you did.

Then, as already mentioned, you still need to power the arduino through either

  1. USB
  2. DC Jack
  3. The Vin pin - this is the most dangerous solution, I do not recommend it for nubes (not to be cocky, but you did say you are new to this).

Essentially, the Arduino is not configured to be powered in your current circuit diagram.


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