Electric gate controller

Hi, I have an electric gate (swing x 2) and I would love to replace the controller with an arduino setup. The current one is a Serai CR/31 (http://www.merrimack.ie/automation/files/pdf/CR31manual.pdf).

Does anyone know of an open-design one that may exist?

thanks!

(deleted)

I would love to replace the controller with an arduino setup.

Why? What do you want it to do that it doesn't do now?

Hmmm... Does your WiFi signal reach the gate, even if onlly weakly?

Wow,

I looked at that picture, and you'd think this belongs in the NASA moon launch headquarters.

If all you want to do is open and close a gate, you can probably get 100 m. line-of-sight with a number of different transceivers. The lower the frequency, the better because low frequencies attenuate more slowly with distance.

Just use an arduino tied to a transceiver at the gate (Nano + RFM22B from Hope is good combination), and build a little portable hand unit with Arduino, RFM22B and batteries.

Adding a standard available relay board or shield to an Arduino will provide an easy and safe way to control the gate motors form your code.

spycatcher2k:
Why not just design and make it, or buy an off the shelf replacement? I you want someone to supply the code & circuit for a specific direct replacement then you may be in for a long wait.

Eh? I intend to but I was not for reinventing the wheel if someone had already done this.
I could buy an off the shelf replacement but I want to have one I understand and can learn from making it. I also would like to hook it into my my current MySensors network (I already have a reed switch on the gate to log/alert on open/close).

Basing off someone elses work would be a huge leg up and also give me an understanding of all that is needed. I have bought a GSM receiver and I can reuse my existing key fobs and access control pad. I just wanted to look at replacing the controller main board and was interested in logic around the motors and when to stop them etc.

This was in no way meant to be a lazy request for someone to do the work for me. I want to do the work but I’m newish to electronics so I will take every chance to learn. I sincerely thought that was the purpose of these forums. Apologies.

yfaykya: I want to do the work but I'm newish to electronics so I will take every chance to learn. I sincerely thought that was the purpose of these forums. Apologies.

No, we apologise. We get so many newbies here on a daily basis who can't be bothered to learn, want and expect that a quick ready-made solution to their particular problem must somehow already be available and seem to believe this forum is a free service for writing code or just doing Google searches for them. It drives us all nuts.

A case in point:

sherinajumal: I am new to arduino learning about arduino is so cool :) I wanto make an alcohol controlled engine stopper could anyone give me circuit diagram and program for it ? Thank you

There is 2 types of arduino newbes, the ones that want to learn and keep going in their lifes
with arduino and electronics designing and making projects every month/year and the 2nd
type that join forum just for a single project and asking for help for their problems, resolving it
and that’s all for them.

D.60

to reverse engineer what that controller does, you should make a table for each DIP switch and detail what each one does and then ignore those functions you do not plan on using. attendant mode may not be soemthing you think you need, but they have included for a reason.

often you will find that such devices can be used on multiple applicaions and with multiple types of motors. does your motor require only a single pulse, and then goes through it's routine ? or do you close a relay and keep it closed until you reach the end stop, then do you hold or time out or reverse ?

whenever you have something as common as an iPhone, there are thousands of people trying to crack that. when you have something like a gate controller, you might be the 2nd or third.

best to search this list for your key words google gate controller arduino but also gate controller microcontroller gate controller pi or raspberry......

Thanks all. Using the dip switches as a guide is a good idea. Not sure how the motors work (pretty sure they are AC though). I had to change a big starter cap for one of them recently. Notebook and pen time :-)

Use relay

Hi all,

So I drew out all the inputs etc of my current controller and I have a good handle on it. The only thing I am unsure of is the driving of the AC motors. I would need to start slow I assume and also I want to somehow detect obstacles (for safety reasons - I have young kids).

Thanks!

yfaykya: So I drew out all the inputs etc of my current controller and I have a good handle on it. The only thing I am unsure of is the driving of the AC motors. I would need to start slow I assume and also I want to somehow detect obstacles (for safety reasons - I have young kids).

You forgot to attach your drawing!

Do the gates have obstacle detection now?

When you say "start slow" do you mean because you are a beginner, or do you want the gate's motors to start slowly?

You forgot to attach your drawing!

Do the gates have obstacle detection now?

When you say "start slow" do you mean because you are a beginner, or do you want the gate's motors to start slowly?

I will attach in my AM! By obstacle detection what currently happens is that if the gates hit something they pause and I think reverse - need to recheck that (there is a voltage selection between 180 - 240v - my understanding is this sets the resistance the gates need to stop). If they don't reverse I guess that could be used to detect when they are closed. Otherwise I need to suss that out too.

By slow start I mean the latter. I had read somewhere that the motor should start and end slowly.

I think I should try and measure the voltages on the motors and try and graph it. Don't have a multimeter that can do that nor an oscilloscope though. Maybe I could jerry rig something up with an arduino...

Don't risk electrocuting yourself. The Arduino can't withstand AC mains voltages. Your multimeter might register the difference. Or maybe not. If the motor does indeed start slowly, this won't be achieved using lower voltages, no matter what your multimeter shows. It will almost certainly be done using Pulse Width Modulation. You will need a scope to really see and understand what's going on.

Hi.. yfaykya

the fact that you had to change a big capacitor on your motor makes me think it's a standard squirrel-cage type.. These have 2 coils - one connected directly to the mains, one via the capacitor.

You can reverse them by inverting one of the coils with eg a relay, but you can't vary the speed very much by changing the drive voltage. You'd need to change the drive frequency for that - much more difficult.

regards

Allan.

The motors have 3 wires Common, Open, Close (and earth) with the cap across Open & Close. I assume that is for smoothing the voltage The Cap is a motor run cap.

Pic : Dropbox - 1 photo

The arduino is a MySensors node connected to a reed switch on the gates.

This is the motor :Dropbox - 1 photo

The voltage settings I mentioned earlier for detecting obstacles is from 220-125.

I did some quick tests just now and it seems the stop limits might be determined by time. I held one gate for a couple seconds and when I let it go it did not complete its full open. It was also pretty hard to hold it! Not sure I like how safe that is!

The motor is almost certainly a squirrel cage and is wired as per the attached schematic.

The capacitor is essential for the motor to run.

regards

Allan

scage.pdf (15.1 KB)

allanhurst: The motor is almost certainly a squirrel cage and is wired as per the attached schematic.

The capacitor is essential for the motor to run.

regards

Allan

Thanks Allan, Do you know how these motors usually define their "limits" with regards opening and closing? Is a constant voltage ok?

The capacitor it there to make the motor run in the desire direction.
It is there to cause a phase delay on the coil it is across.
If it were not there, the rotor would just vibrate unless spun
in the desired direction first.
It has nothing to do with filtering.
These motors can not be speed controlled they run at a rate defined
by the frequency and spacing of the internal parts.
They are not quite synchronous because they allow some slip with load.
Varying the voltage will have little effect on the RPM. If too low a
voltage, they will just stop and buzz.
They only have the two functions, forward and reverse.
Dwight