Attach servo and control with RC7

I am trying to control a servo with the channel Rc7 of my transmitter.
I tried to follow the guide: copter.ardupilot.com/wiki/camera-mount/ just to enable to send the right signal to my servo but nothing good so far…

On the APM1 I was attaching the servo directly to the output and put RC6_FUNCTION = 1, but it seems that the frequency has changed and it wont work anymore.

I am using an external battery to power the servo;, so it wont be powered from the APM,

@max246,
Do you have a common ground between the servo output of the APM and the servo itself? If not, that might be your problem.
Regards,
TCIII Admin

Yes I have it, but I read that I should attach to the pin A10 or A11 because the frequency is lower and better to control a servo.

Could someone give me some steps how to attach it and control via remote controller so I can double check my steps?

Problem solved, I was connecting the servo to the SPI port, I didn-t check the alignment from the box with labels and pins ( I guess you should just add another label for the NC slot.

I got a nice 3.7 booster to 5v and made a connector for my servo.