Hi
Glad to be on this forum I am a absolutely new  to RC world
I really need you guys to help me out. i am in process of acquiring a DJI phantom4 drone for my professional use. Since i an also an angler and go surf fishing i need to develop a bait release mechanism to be fitted on it  to use the drone for sending my bait into the sea. Since i can not connect any thing to Phantom 4 control board i would need to make a payload switch which operate by a separate transmitter switch i just need to send a open a and close signal say a up to 500 meter  to a switch which is some thing like this

I have seen this accomplished with just a ring attached to the line and steel rod attached to the Quad.

Hi thanks for the revert
I have already seen this and few more on youtube and believe me 100 things can go wrong in doing this, manual release is not going to work for me. That's the reason i want to build this switch and have decided to do it my self there are also some other options of buying a ready made mechanism for Phantom 4 but they are too bloody costly. Most of all I want to do it my self  . i know this much that i would need a transmitter and a receiver also a power source but of what kind is the question . I just want to operate that servo arm.