Camera triggering - not very straightforward

I am trying to set up a camera trigging system using my 2.5 APM to trigger a modified USB-cable pretty much how it is described in a separate tutorial (*). Now, the tutorial is no longer current and I am left with half the story.

In this process I have found that I am missing a way of “triggering” signals on the signals row (A0-A11) on the APM for testing purposes. Is there a way to trigger signals from Mission Planner (1.2.80) to emulate a signal in flight? Am I missing something here?

The guideline which takes me furthest for this purpose (**) suggests using the RC transmitter to do the testing. The truth is I am not really interested in setting up my system for taking pictures using the transmitter - it seems like it is in itself a rather complex undertaking. I would rather test this before taking the copter up in the air.

Any suggestions on how to do this?

*) … -tutorial/
**) … -tutorial/

Not sure I understand your issue as the links you mention indicate perfectly working instructions. Maybe you do not get a signal on A10 or A9 when you trigger the camera?
To do so make sure in mission planner that you went in the config/camera setting, chose the Ax channel, setup the right PWM value when triggered, servo mode. Then make sure in the standard PID screen to select Ch7 as “camera trigger”

I use a arduino nano board running a small script reading in a pwm signal from ardupilot and then closing the focus pin then closing the shutter pin. If you are familiar with arduino I can send you the file if you like… I don’t think just hooking up a modified usb cable will do it… I can send you a programmed board ready to use too if you get really stuck…

Oh, I forgot to add, if you can trigger the camera via the tx on ch 7 then the do_digicam control function through mission planner works fine.
My trigger system (previous post) can also be set up to just trigger every X seconds if required…

to which pin of APM2.5 have u assigned the camera shutter servo (DO_DIGICAM_CONTROL).

i have solved the issue. the camera_shutter pin is not A8 (also called RC8 in wiki). The camera shutter pin is RC8 which is pin 8 on OUT of APM. assign RC8 in camera configuration for camera_shutter and connect the servo used for shutter to RC OUT 8 pin of APM (on the rear side). select camera_shutter to servo from Standard Parameter list. it then works fine. ofcourse you can chk the servo by assigning CH7 of Tx to camera trigger. now the shutter would work on using the command DO_DIGICAM_CONTROL in mission planner.