Doubt in servo connection

Hi,

I’m a newbie in rover ardupilot. I have a doubt relation servo connection. In rover documentation informs that is necessary to provide a 5V BEC power to pixhawk in order to use servos (Figure below).

I bought the following ESC with BEC (xt-xinte 30A BEC 5V/3A) :

Can I use this ESC for this purpose? If yes, regarding the connection with pixhawk, I have three cables (blue cables) to connect but as we can see in figure above only two are required ( I think they are power cable). Which ones should I use?

Felipe,

That ESC has a built in BEC so you won’t need the external 5V BEC shown in the picture. I guess you’re using that ESC to control the rover/boat’s motor… or are you only using it as a BEC?

If you’re only using it as a BEC then you can just plug it into any unused output on the back of the pixhawk. The black wire should be at the top, the red in the middle and white on the bottom (at least if you’re using a Pixhawk1 or similar). If you’re using the ESC to move the motor then it should be plugged into MAIN OUT 3.

By the way, it’s a bit dangerous to power the Pixhawk only from the rear servo rail. It’s best to use a power module which provides separate power to the pixhawk through it’s POWER port. The issue is that servos can sometimes cause a fluctuation in the voltage and if power is only provided through the real servo rail, that fluctuation will flow into the CPU and sometimes that can cause a “brownout” and the board may stop responding.

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@rmackay9 Thanks for your response. I bought this ESC for my drone but I liked to use in my rover. My objective is using this ESC only it as a BEC because of the pixhawk requirement to move steering servo. I’m using pixhawk 1. Bellow, I draw a schematic for connection. Did I understand correctly? (Sorry for my terrible drawing :frowning: )

Regarding rear motor thanks for your explanation but I’m using this ESC (link bellow) to power the motor. I tested using the “Test motor” option available um Mission Planner and it works correctly.

Thanks.

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Felipe,

It looks to me like the Brushed ESC Speed controller also has a BEC built into it. I think this means you don’t need the brushless ESC.

The drawing looks pretty good. The brushless ESC’s red and black wires would need to be connected to the battery of course.

Just to be clear, the point of this BEC is to provide 5V power to the rear servo rail of the pixhawk.

The servo has six wires? I wonder what those are for… anyway…

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@rmackay9 Thanks for your reply. I thought it would need power because in the rover’s documentation it states the pixhawk has no power to move a servo, in my case the steering servo.

http://ardupilot.org/rover/docs/common-servo.html

So in my case, I only need to connect the steering servo cable (three cables) in MAIN OUT number 1. Pixhawk will move the servo correctly.

"The servo has six wires? I wonder what those are for… anyway…"
I made this question for me too. But in rover has two limit switch and one buzzer in servo shaft, maybe these extra cables are used for this purpose.

Thanks.

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