Can camera's servo code works for another servo?

software

#1

Hi

We are using an extra servo in OpenROV and we tried after doing the connection to plug it into camera servo’s pins in the controller board, just to check if it wil rotate but it didn’t …

was this wrong ?

This is the servo we are using


#2

@asmoo_191,
How deep are you planning to dive? This servo is only spec’ed to 1 meter. It might not survive a 33 meter dive.
Regards,
TCIII AVD


#3

I’m not going to dive so deep


#4

The servo should work just fine if you plug it into the connector for the camera tilt (D11). I’d reconnect the camera tilt, check that to make sure it’s operating, then switch back to your test servo. Also, if you’re going to play around with servos, I’d highly recommend having a servo tester around, something like this. That way you can tell if there are issues with the servos themselves, before tearing into your ROV hardware.

-W


#5

We used a multimeter to check if the power is reaching the servo and it showed 5 volts when no signal is sent , and 3 volts when we press on the keyboard to send a signal …


#6

You should test the servo with an external power supply and a servo tester, to see what’s up with it.

The power for the servo comes from the 3 BECs, one of each of the 3 Afro12 ESCs. The BEC on each ESC is spec’d to source 0.5A at 5V, so you should be able to get 1.5A of current to the servo. The servo you picked has a stall current of 1.8A at 6V, so it should be somewhat lower at 5V (see the spec sheet for the servo). In summary, the controller board should be able to provide enough current to drive your servo, even at stall.

Question: What are you using to power your controller board? Is it running off of batteries, or a benchtop power supply? If you’re running off of a benchtop supply, make sure it can provide enough power.

Anyway, hopefully this provides you with some ideas as to how to debug what’s going on.

-W


#7

"The servo you picked has a stall current of 1.8A at 6V, so it should be somewhat lower at 5V (see the spec sheet for the servo). "

So we can control how much voltage can reach the servo through the code, am I wright ?
If yes is there any useful threads for that?

“Question: What are you using to power your controller board? Is it running off of batteries, or a benchtop power supply? If you’re running off of a benchtop supply, make sure it can provide enough power.”

Batteries , openRov batteries


#8

No. The servo is powered with 5V all the time.

The servo position is controlled by a PWM signal from the ATmega processor, whose high time varies between 1 msec and 2 msec. If you’re unclear on this, you should search around the internet for some basic tutorials on RC servos.

-W