Not enough power to control the ESC?

Other Hardware Motors, Mechanics, Power and CNC
1

Hi,

I am using an Arduino Mega to send PWM signals to an ESC (Electrical Speed Controller) which controls a brushless motor. Programming-wise, I am using the Servo library. It works perfectly when the Arduino is connected to my laptop via USB cable. However, a problem emerges when I try to use a battery to power the Arduino. The ESC keeps beeping which indicates that it is not receiving signal from the input pin, as if I did not connect to that pin at all. My battery is a cubical 9V one.

The same problem also appears when my laptop is not plugged in to AC power source when connecting via USB cable. The motor and ESC are powered by a huge battery or a DC power source in the lab which outputs up to 7A. I also tried to use the power output from the ESC itself. The ESC has 5V output when it is powered by other larger power source. The problem still exists.

I am wondering what kind of power source can solve this problem. Since everything can only work when the Arduino is connected to my laptop with AC plugged in. Or it is something else other than the power problem?

Thank you in advance.

2

It works when you have the laptop plugged into the wall and your lab power source because both are sharing a ground. When one side is a battery (either the laptop on battery or the ESC powered by battery) then there is no connection between the grounds.

Connect the grounds. All will be well.