Hi, I came across this site in search for a solution for a little project and wondered if I should look deeper into Arduino.
Gates will open and cut a photocell beam making a string of LED lights come on, then off again when the gates close and the photocell beam re-connects.
Unless a daylight sensor tells it to not come on.
With the option of over-riding the lights to come on and stay on operated by two seperate wall monted switches.
Always open circuit when daylight sensor is detecting daylight.
Closed circuit when light beam is cut on gates.
Always closed circuit if one of two switches is operated.
Please excuse my lack of knowledge and my poor explanation I'm sure I'd get my head around this if this is a possible controlling method.
The average Arduino board such as a Nano could do what you describe but you might like to consider a board with Bluetooth and/or WiFi connectivity to allow remote control, monitoring and code upload
You don't even need a "beam" of anything to detect gate closure. You can do it all in LDR. The light to the gate will still change, even at night if obscured by the gate. Or if it's a really dark gate in the middle of a farmer's field or something, I'd use a reed switch/sensor module on one side and a little magnet on the other. That's how door sensors in common household alarm systems work.
I think @UKHeliBob means "scope creep", meaning that as @marksson explains in more detail what is required, more and more complexity is revealed that was not considered to begin with.
The reed switch etc wouldn't work as the gates aren't manufactured to a close enough refinement, which is why I was thinking of a photocell being cut off by the gates opening. LDR would well though for night/day light.
Mains 240v supply.
Gosh, thank you all, more answers than I expected, which raises more questions. This isn't my field at all but I get the impression this could be a good solution for this and other projects, love the idea of then being able to use a 'remote'.
Where would you suggest I start with this? Maybe one of the educational packs?