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Adding extra switching relays with new QGC


Hi there, working with a standard BR2 rov at the moment but also interested in using the BR2 platform for a different project where we don’t need thruster control but would want to control several relay switches. I noticed the latest release mentions extra relay controls. Can anyone explain in simple terms how this works and how to implement it? How many relays could the system run assuming no motor controls?


(Jacob) #2

It’s technically possible, but would require your own custom software.

ArduSub provides for only 3 relay outputs at the moment. An easier route might be to add an arduino with your own small program for the relays.


Ok thanks Jacob.
So its possible folks, anyone out there got any advise on how to actually do this is practice though for an Arduino numpty like myself… :slight_smile:
I’ve been building ROVs and UW camera systems for years just not using this Arduino tech and I can’t believe that others haven’t wanted extra switching channels on their ROVs for manipulators, lasers, lights etc etc…???

(Jacob) #4

lasers = pwm
lights = pwm
manipulator = pwm

We use pwm to control most things :slight_smile:

Can you explain more about what you are trying to accomplish? What are your goals and requirements?

Arduino is targeted at beginners, my advice would be to get one and start doing some tutorials.

(Etienne Demers) #5


Do you have more details on what you are trying to achieve?

I am presently building a Survey pod with the following characteristics:

  • 8 relays for I/O
  • Leak sensor
  • 12Vdc or 5Vdc out
  • 7 network channels
  • 8x 500mm tails
  • 6x plugs
  • Control software

This will not be going through QGround control but via the ethernet connection on the fathom-X board. (You will need my network upgrade to be able to connect it)

I am waiting on some parts to finalize the brackets and make sure it all fits in a 3 inch enclosure.

With this you will be able to turn cameras on/off, lasers, sonars and control whatever uses ethernet.

I will also add RS232 support on some channels if there is enough room for it.

Is this something you would be interested in?



Hi Etienne,
Thanks for your reply.
We have an old drop cam unit which uses relays to control a 4K camera shooting video and a separate stills camera. we also have relay controlled LED lights and Scaling lasers.
I was interested in the possibility of using the BR2 system to give us an additional HD camera with tilt as well as the compass, depth and lighting functions. We don’t need the speed controller functions for motors as we don’t have any so I was hoping there might be a way to use those channels or another system to control the relays required. Ideally I need 8 relays.

(Etienne Demers) #7

Hello Gavin,

My pod will definitely be a good option for you.

Estimated price for the whole thing about 500USD. But you will need my BR2 network upgrade for 200USD in order to install it.

Let me know if this is something you are interested it.



Hi Etienne,

So if I can still use the Camera and telemetry data this sounds interesting.
What sort of time scale are you looking at to get this finished and tested?
I wouldn’t need any of the brackets or enclosures as we would build it into a custom enclosure.
What would the topside control consist of?


(Etienne Demers) #9

Hi Gavin,

If you will install it in the same enclosure as the fathomX board then you do not need my network upgrade but you will loose 3 of 8 ethernet connections. I can also get rid of the price for the enclosure, brackets, etc.

You will just need to run my software to control the relays. This can be installed on any computer provided its connected to the same network as the BlueROV2. If you have a touchscreen, you will be able to ‘‘push the buttons’’.

I could add USB joystick interface but this will take more time.

Alternatively we could make an independent ethernet joystick interface but that would require additional time to prepare.

If you want to make a hand drawn sKetch of what you want I can price it for you.

Time frame is going to depend on what you want but I should have it ready within a month.



Thanks Etienne.
yes I can certainly mount everything in the same enclosure. Physical engineering of housings is easy for me, not so good at the electronics side of things!
So ideally what I want to end up with is the USB camera, tilt control, depth sensor, compass, light switching and voltage monitoring from the BR system plus 6 to 8 relays I can use to switch functions on the existing camera system.
All this should work through the existing Fathom X twisted pair control. It would be ideal if these relays could be operated by physical buttons like the the BR controller but if thats problematical I should be able to work with screen buttons.
I don’t need any of the 6 thrusters or their related speed controllers as this system has no motors.
If its easier to continue this by email you can mail me on gavinnewman@mac.com
Cheers, G

(Etienne Demers) #11

Simple enough. I’ll send you a quote on your email.