Looking for a sensor

[777upender]

Hello Friends,

I am working on a project with raspberry pi which have an integrated camera.
Currently, i am looking for a Sensor which could trigger the Camera from a distance of 100m (i would probably use RS 485 communication from Sensor to Camera)

Please let me know what types of Sensors can i opt for this project

Looking forward for inputs

Thanking you

[bensimmo]

A switch, like a light gate, or a pressure pad, PIR? Just need power to keep the circuit viable over a 200m run to the gpio pins for the trigger.


What have you thought of and why RS485?

[777upender]

Yes because of the distance 100m i would like to use RS485 Communication
Let me know if i can use any other communication protocol