I don’t really understand the problem. Can you explain a little more.
The Android app sends the drop data to the dropController which then turns the valves on and off and triggers the camera and flash. It does not trigger the camera. This is done by the dropController.
The camera triggers are on D10 and D11. D10 is the shutter and D11 is the focus. For testing, you can place LEDs (plus resistor) on these pins. This will give you a visual indication the triggers are firing.
I have a dropController “simulator” that I use for developing the code. This is just an Arduino and some LEDs but it clearly shows when things are being triggered.