Voltage problems with my servos when the gps is plugged

I am not very good at calculating the voltage and current needs.

I built a circuit that basically has some sensors and servos connected to it and I control those using my Arduino. My servos are not working properly, they are moving like crazy. I had this problem before and it was because of insufficient power supply. So I measured the voltage on my servos, it is going way down to 4V but my servos need 4.8V or higher. And when servos are moving abnormally, my led is dimming constantly.

I was troubleshooting and I found out that when I plug the gps out of the circuit. Everything is working very normal. And it is not necesseraly power cables that I have to plug out. When I plug out the rx or tx signal cables, circuit worked normal.

This is my circuit: (I forgot to draw but ardunio and battery has a common ground)

I am using:

sg90 micro servo (2 of them) : http://www.ee.ic.ac.uk/pcheung/teaching/DE1_EE/stores/sg90_datasheet.pdf

Ardunio Mega :

12(+- 1) V Li-po battery as power supply

GPS neo 7m:

https://www.waveshare.com/wiki/UART_GPS_NEO-7M-C

As 5V regulator, I am using the one built in the ESC:

The UBEC in it, it means regulator I guess, is 5v 2A.

Note: I can use the Arduino's built-in 12 V power input as well if it will solve anything.

I am a electronics noob but my estimation would be that I should get a regulator that can supply more than 2A.(??).

Thank you for your input

Hi,
Have you got the gnd of your controller connected to the gnd of the 5V regulator?

A hand drawn circuit with pin labels will be better,

Tom... :slight_smile:

Yes.

As I said, the circuit works flawlessly when the GPS is unplugged.

Note that I tried to use a 5V 3A Regulator. The problem still exists.

I am positive that it is not a software-related problem. The hardware is also good. I tested each independent from the circuit. It should be about the voltage or current or something

Hi,
Can you please post a picture of your project so we can see your component layout?

A hand drawn circuit with pin labels will be better with all connections.

Does your LED have a current limit resistor?

Have you checked ALL your gnd connections?

What 5V 3A regulator?

Thanks.. Tom.. :slight_smile:

It should be about the voltage or current or something

The something is the total lack of any power supply decoupling on any of the servos, even if the power supply is up to it, which sounds unlikely. The power supply is on the limit as a servo can draw an amp or more when it starts to move. Interference from one servo can easily cause miss triggering on the other.

Note: I can use the Arduino's built-in 12 V power input as well if it will solve anything.

No it will make matters worse.