What kind of sensor would be best for an entry gate

What kind of sensor would be best for an entry gate. To the fact that the car tries to go under the gate while it’s closing. Thank you

Best would be magnetic loop - but it's large and need to be buried. But maybe you need more than one... an interrupter with IR could keep the gate open until the vehicle is safely passed.

I don't understand exactly what you're trying to do, but maybe you can build or buy something like [u]this[/u].

...If you buy one like that from a home improvement center you might not get all of the specs because it's designed for a particular system and the typical buyer just has to wire it in without knowing the voltage & current, etc.

I wish I knew what it was called, it might be IR. But for some reason I keep thinking TV remote with ir. But it beam of light essentially admitted on one side it's a reflector on the other side comes back to the first side and is detected.

birddseedd:
I wish I knew what it was called, it might be IR. But for some reason I keep thinking TV remote with ir. But it beam of light essentially admitted on one side it's a reflector on the other side comes back to the first side and is detected.

Not useful when covered with rain water, ice or snow.

Paul

magnetic loop still works :slight_smile:

Most of the ones I have seen are photo eyes close to one side of the gate - when the PE's are blocked the gate stays open - for the gate to close requires to gate to have been open for a specific amount of time AND for the PE to have been cleared for a specific amount of time

What would be the difference between a photo eyes sensor and an IR brake light sensor?

I don't know what a "brake light sensor" is - - but the industrial PE's I worked with used light that was not visible so they did not have problems with ambient light -

The sensor is not intended to open the gate (or barrier), it is intended to prevent the gate closing when a car is under it. Is that right ?
A photo electric beam break sensor system is typical for such an application.

there are a few ways to do this... best IMHO is the magnetic loop... nothing to ever get stuck/blocked/less chance of breaking.

When I lived in California, there were many photoelectric sensor - it doesn't snow and hardly ever rained.

I live in Chicago now and it's already started snowing. 3ft snow drifts are common. In Any case here are some examples:

the question was what's the best sensor for gate... I still believe the mag loops are best.

You will have to adjust if you want it to pick up motorcycles.

the center loop is for safety... you can add and electric eye to the posts if you want more safety... also check with your local regulations.

Where can i get a magnetic loop for a mn arduino

google it… you can build your own.

wolframore:
google it... you can build your own.

Maybe something like this to create a signal that changes:

http://www.engr.usask.ca/classes/EP/424/lab/EP414LabManual/node5.html

Maybe something like this to read the signal:

https://tushev.org/articles/arduino/9/measuring-frequency-with-arduino

You may have better Google Fu.

A magnetometer chip like the HMC5883L can easily detect passing vehicles several meters away, by measuring the distortion in the Earth's magnetic field caused by ferrous objects.

I use one for a gate alarm, to detect cars entering our driveway (about 300 meters from the house).

Much easier than burying a wire loop, and building the associated circuitry!

Thank you, but that seems like some pretty high-tech stuff. I would never guess the magnetism would ever be that sensitive

that seems like some pretty high-tech stuff.

Not at all. Just an electronic compass that you can buy for a couple of $. Here is a beginner tutorial.

Your own old fashioned needle type North-pointing compass (a technology that is about 2,000 years old), won't work well or at all in a vehicle for exactly the same reason.

I recommend a photo eye on the gate area so it doesn’t come crashing down on a non magnetic object

Like a snowdrift?

Maybe that's an important safety feature: when the snow gets deep enough, the gate stays open so that when it's embedded in snow and ice you can still get through.

What’s the false trigger possibility on a magnameter is the gate iron?