Modifying printer to scanner - Gcode mystery.

Greetings fellow 3D'ersI am going to modify my neptune 2D to act as a 3D scanner. I will be using the information found on the website below to make the majority of the parts required.https://www.printables.com/model/232...est-editiThere will be a couple of mods that need doing but that should be no problem. I have downloaded the photo app that makes the phone take a pic at the sound of a beep, BUT here's the rub, I cant get the printer to beep every time it increments to make the camera activate.The control of the bed increments is done by a simple Gcode, I have edited the code to contain the M300 [P] [S] commands at the apropriate time but nothing happens. The printer will beep at the end of a standard print as normal so I know the beeper works.So the question is - Does anyone know how to get the beep to work? there is nothing on the control screen that affects it but might there be something in the firmware preventing the m300 command? I think not but then I'm not an expert on coding.I think this is a great little project for a really cheap 3D scanner but I can't believe it's gonna be scuppered by a beep! Can someone tell me how to fix this please!