Aux port relay - need to command open and closed - no voltage applied

I’m configuring a shutter on a Sony camera - using the Sony Multi-Port connection.

I started by duplicating the configuration I had on another copter with a Naked GoPro.

There I followed the doc instructions - assigning channel-7 to camera relay, and setting relay_pin to “55” for the pins at AUX-6 on the carrier board.

This sends about 3 volts on the AUX-6 signal pin, for the specified number of milliseconds. This operates the Naked GoPro shutter perfectly.

This however failed to trigger the Sony shutter.

I discovered that to trigger the shutter, I simply need to momentarily close the circuit between the trigger and ground.

This means I need the carrier board AUX-6 to function as a “switch” only - open and closed - the default being open, closed when I “press the button” by activating channel-7.

I have no idea if this is possible. So far, I’ve seen nothing in the docs that speak to this.

Could someone please offer me some guidance? Many thanks!

Addendum - I suppose I could wire up a low voltage relay to do this - but if it can be done by the Cube and Carrier Board - it would save me the trouble.

You need to configure that particular output as relay instead of PWM

By default, AUX-5 and AUX-6 are both “relays” - but they don’t appear to act as “switches.” From what I’m learning, I need to have the output of AUX-6 command a real relay, to function as a switch.

It’s probably all this old gizmo had on it:
Sony Camera Trigger
Here is another one:
Camera trigger

Those pins are TTL level relay trigger pins. Unless your autopilot hardware specifically includes relays on board, that’s all they are (any given “relay” pin will provide ground or 3.3/5v depending on the logic level of your board - a binary 0 or 1). The intent is to use them to trigger a relay. If you need relay functionality, add a relay (or MOSFET or transistor).