Open/Close electric gate using computer

uncapped_shady

uncapped_shady

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What would the cheapest way be of Opening/Closing a Electric gate using one's computer?
Either via serial/parallel or usb? there is said that serial cables can give a small voltage that could trigger a relay, but I am not really sure of how to go about doing this.
One thing that i did think of is the remote receiver on the gate motor, that receives a signal from the remote fob and then in turn generates a voltage that opens or closes the gate.

if anyone has info on how to do this on the cheap I would really appreciate the input.

Cheers
 
Does it have to be a computer opening the gate? do you want to use it for ac? and keep records of the log or something?
 
uncapped_shady said:
What would the cheapest way be of Opening/Closing a Electric gate using one's computer?
Either via serial/parallel or usb? there is said that serial cables can give a small voltage that could trigger a relay, but I am not really sure of how to go about doing this.
One thing that i did think of is the remote receiver on the gate motor, that receives a signal from the remote fob and then in turn generates a voltage that opens or closes the gate.

if anyone has info on how to do this on the cheap I would really appreciate the input.

Cheers
Click to expand...


The receiver either closes a normally-open relay, or opens a normally-closed relay to provide a signal to the gate controller.

You could look at something like
http://denkovi.com/product/44/usb-four-4-relay-output-module-board-for-home-automation.html
 
Tiscanny said:
Does it have to be a computer opening the gate? do you want to use it for ac? and keep records of the log or something?
Click to expand...

The idea of it running through a computer is ideal in the sense that I can then RDP into my pc at home and remotely open the gate over the internet if I have to. I can of course go and purchase a controller board to achieve that, but as I said I would like to do this on the cheap. I already have a computer running Windows XP, so if it were something simple as connecting up a serial cable running to the gate motor triggering a reed relay or something in that fashion, then that would be ideal.

I just do not really know how to go about setting something like that up. If the remote receiver could be piggybacked to receive the signal from the serial cable instead of the remote fob frequency or the like it should work, but how I don't know... :confused:
 
Sinbad said:
The receiver either closes a normally-open relay, or opens a normally-closed relay to provide a signal to the gate controller.

You could look at something like
http://denkovi.com/product/44/usb-four-4-relay-output-module-board-for-home-automation.html
Click to expand...

Thanks for the suggestion Sinbad. That is another thing that i was worried about. Lets say for argument's sake that the serial cable can trigger a reed relay that in turn gives enough juice to the controller to open or close the gate. Now the problem is that I think my gate uses a pulse to trigger open or close and not a open/close (the whole time until triggered again). So if I just use a normally open/normally closed relay, would I risk frying something?
 
It can be done from the paralleled port. You can control a total of 8 devices like that. I once build a board and wrote an app to run my sprinklers from.

You have one problem though and that is the low voltage from the port. What you must do is to use a transistor and a relay. The sprinklers ran on 24 volts so I had a transformer that dropped the 220V to 24V and this ran through the relay which was a 24V relay.

The 24V circuit to close the relay ran through the transistor.

So the low voltage comes from your port to the transistor which closes the gate in the transistor, this turns on the 24V circuit which closes the relay and thus the bigger circuit.

I will see if I still have the diagram here somewhere of the board I made.

All you need then is a simple app that prints to each pin. So if your gate is say connected to pin 1 on the port then you print to pin 1 etc...


EDIT: That was in the days before USB. Now, as suggested above, it will be easier with USB as you have a higher voltage for relays
 
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MKFrost said:
It can be done from the paralleled port. You can control a total of 8 devices like that. I once build a board and wrote an app to run my sprinklers from.

You have one problem though and that is the low voltage from the port. What you must do is to use a transistor and a relay. The sprinklers ran on 24 volts so I had a transformer that dropped the 220V to 24V and this ran through the relay which was a 24V relay.

The relay 24V circuit to close the relay ran through the transistor.

So the low voltage comes from your port to the transistor which closes the gate in the transistor, this turns on the 24V circuit which closes the relay and thus the bigger circuit.

I will see if I still have the diagram here somewhere of the board I made.

All you need then is a simple app that prints to each pin. So if your gate is say connected to pin 1 on the port then you print to pin 1 etc...


EDIT: That was in the days before USB. Now, as suggested above, it will be easier with USB as you have a higher voltage for relays
Click to expand...

Thanks. I would appreciate it, if you could pm me the diagram if you manage to find it somewhere. Cheers buddy
 
Maybe try something like this? http://electronics-diy.com/USB_IO_Board.php

Hook it up to a gate remote control (power the control through usb if possible) and use the outputs of that USB IO Board to drive a transistor which will complete the circuit for the button of the gate control (you solder onto the gate control).

I obviously haven't full thought this through (might need to limit voltages to the control/ add circuitry so the device can't malfunction etc.) but that solution seems simple enough, and not too expensive (I can't see that circuit costing more than R100, assuming you have access to a soldering iron, and don't break anything)
 
uncapped_shady said:
Thanks for the suggestion Sinbad. That is another thing that i was worried about. Lets say for argument's sake that the serial cable can trigger a reed relay that in turn gives enough juice to the controller to open or close the gate. Now the problem is that I think my gate uses a pulse to trigger open or close and not a open/close (the whole time until triggered again). So if I just use a normally open/normally closed relay, would I risk frying something?
Click to expand...

The receiver pulses the relay. You need to emulate this.
 
HeineKo said:
Maybe try something like this? http://electronics-diy.com/USB_IO_Board.php

Hook it up to a gate remote control (power the control through usb if possible) and use the outputs of that USB IO Board to drive a transistor which will complete the circuit for the button of the gate control (you solder onto the gate control).

I obviously haven't full thought this through (might need to limit voltages to the control/ add circuitry so the device can't malfunction etc.) but that solution seems simple enough, and not too expensive (I can't see that circuit costing more than R100, assuming you have access to a soldering iron, and don't break anything)
Click to expand...

Thanks HeineKo, that looks like a very good starting point (and cheap enough).:D
 
Is the main reason you want to use a PC for opening the gate the price of a GSM/Gate controller?
 
Add a cheap 'phone, pack it in a Tupperware box....

http://www.electronics123.co.za/Main.asp?D={2BEAFB5E-1A1F-4562-910F-A2FB1F9DDE57}&PageType=Product&SKU=GB819&CategoryID=1514
 
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