Are there any other alternatives, for example via the USB port?
I would like to control an external device (Motor Slider, Plant Lamp) in a time-lapse script via Arduino. Since that seems to me to be an elegant solution with the HDMI 5V output. If I understood correctly then the 5V voltage can also switch in recording mode.
Does it work even if the camera is in half-pressed shutter?
Could you also generate pulses (3 * 50ms with 50ms break)?
If you want to experiment with this, you can find EnableHDMIPower and DisableHDMIPower in the funcs_by_*.csv for your camera, and call them with call_func_ptr(0xwhatever)