Automating the gate

So @nogthree has been doing an amazing job getting the security swipe in system going and he’s mostly done when it comes to doors I hear. :golf: :clap:

The next big hurdle is interlocks on tools. So I might as well throw another thing into the mix.

It would be super useful to automate the gate, so that it becomes part of the swipe in and out system, solves the padlocking problems, stops it being left open or having to call security to close.

So here’s a motor!

I think the only ‘tricky’ part of the implementation is figuring out how to mount the rfid reader for ingress/egress so they can be used by people in cars. I’m thinking we’d need to dynabolt some poles to the concrete in places and get creative with doing some cable runs. Or alternatively, wifi, if we can power them in some other way (battery + solar?)

Thoughts? Anyone keen to implement? Got a better motor? Lets chew on this idea for a bit :slight_smile:

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@Dynamite has suggested in slack that we could run cables by utilising speed bumps.

Need to do some quick maths on the trickle circuit requirements, but if we set up a wireless based rfid reader all we’d need to do is provide 3.3v at the reader via solar.

If we had a ‘press butan then swipe’ arrangement we wouldn’t need to keep much power in the reader box.

Not super helpful but I’m pretty sure there’s some ethernet that’s cut off chilling in the road opposite the gate. If not the speed humps, running the power along the fence in conduit would work just as well. If we go WiFi, that means only one cable. If someone is super keen, could almost run power inside the big tubey bits of the fence.

There were a couple of linear mechanisms in the boneyard that are perfect for opening/closing the gate. It runs off 24v… probably at a few amps or more.
I took one last night , removed the irrelevant bits , tested that it moves in both directions , etc. It’s now stashed in the server room. When at its shortest this one is approx 400 mm between it’s end mounts. When extended it’s 600 mm.
This particular unit has 4000 Newtons force.(a bit over 400kg).
Thanks to some help last night From Crofty and others one of the gates will now swing inward nearly 90deg which is enough to drive through easily.
I thrashed out rough the mechanical mounts needed to mount this linear mech to the gate and it will need some welding but is totally do-able. If someone wants to fab/weld up the metal stuff pls see me or crofty as it’s not complicated but needs to work reliably.
Nog has also suggested that he has an idea of how to make the RFID stuff work out at the gate…
So now we just need this idea to all come together and it’ll be awesome!


If we can use POE (real or just low voltage stuck on the extra pins) then we can run it via just a Cat5 cable, so pretty much its going to be a single cable regardless if its data is wireless or not. Still a good idea to put it in conduit though… keeps the UV from destroying the cable run over time.

The reason I suggested a separate power cable is due to the fact you’re going to have a fun time pushing 3A at 24V over ethernet for that long of a run.

There’s no way you can put enough current thru a long cat5 run to power the gate motor. Much more sensible to run 240v thru a conduit on the fence line out to a proper weatherproof box where all the controls etc can also be located.

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Yeah, you’re gonna have to run power+data to the motor and controller in some sort of conduit, probably just dig it into the ground where the asphalt stops.

As for the swipe facility we’ll see if we can do that wirelessly since it will have to be on the other side of the driveway, so running cables over the driveway will suck.

Honestly my brain was in neutral and I was still thinking of the swipe\electronic lock when I said POE, not the motor, so derp.

On the other hand if you while its not the most sensible idea, if you really wanted to make it work then it would be simple enough to to put a cheap 500mA charger and fairly small but fairly high C rated battery in the control box. this would be fine for running a 24v motor for the short-ish duration of activation, even a few times in a row. Or on a slightly more dodgy suggestion, max POE capacity is ~25w, so if you put a decent sized super cap in the control box chances are the gate would work with running straight from a switch mode step down… but I really hope that idea stays in the “it may be possible” bin rather than being something that gets built.