I've built a boom barrier gate for my building and now I need to be able to control it remotely.
Naturally, all the electrical components are housed inside the metal cabinet.
According to my design and application, the module has to:
Operate within 10 to 15 meters (30 - 50')
The ability to respond to multiple remotes
Send a pulse to Arduino when a recognized remote is pressed, maybe with a built-in relay?
The ability to add/remove remotes from within the board, or maybe I can make another Arduino board and attach the RF module to it so it's sole responsibility remote handling.
I need the freedom to buy additional remotes and not stick with the 1 or 2 remotes that comes with the unit.
I think it's obvious that I'm not experienced in this area but I also think you got the picture
For the operating frequency: I live in Jordan so the rules are a bit lax but I hear 433Mhz is common band for hobbyists.
Since you are in Jordan, you are in "ITU Region 1" meaning that 433 MHz should be a license free band for you. As a result, there are a number of LPD433 radios commercially available. Many of these use LoRa technology, such as this one, to provide a decent range at a very low power. I should say these radios require an Amateur license in the United States, but not in Jordan (to my knowledge. check with local authorities.) Yes, you will need a micro controller to "encode" the remote controls into a broadcast signal. And, you will need to program the micro controller at the boom barrier to "decode" the control signal. This can be as simple as an ASCII text string.
Now for the remotes, if I go to Alibaba and look for 433mhz remotes, can I safely assume they would work with this Ada's module?
I don't really want you to feed me the answer, if you could direct me to any source where I can better understand how encoding/decoding works that would be great.
aminabudahab:
Thank you Perehama for your response,
Now for the remotes, if I go to Alibaba and look for 433mhz remotes, can I safely assume they would work with this Ada's module?
I don't really want you to feed me the answer, if you could direct me to any source where I can better understand how encoding/decoding works that would be great.
Again, thanks a bunch.
"Work with" is such a vague description. I would safely assume they would not work. It's possible that on some level they might work, but more than likely, they wouldn't even know how to shake hands. I would get 2 Ada's transceiver modules and make my own remote. Radios work best when paired. If I was sourcing from China, I would get a matching remote transmitter and receiver pair. Using transceiver modules allows you to interface them according to a protocol that suits you. For example, no need to receive 250 bytes of data if all you really want is "A1" to know A is on.
I have used an RFM69 radio in a "My Sensors" project, however I believe they would be easy to setup in a simple data communication mode (i.e. two adruino's each with an RFM69.
I was operating ant 915 MHz and could easily reach 50 meters. I would assume 433 Mhz would be even better.
They may at first seem like overkill but with the arduino libraries they should be relatively easy to setup.
You should be be able to find a large number of these radio's on ebay.
Planning to put a transmitter in a thick metal box is, in my view, a very big mistake, you are designing a system for failure.
A thin tin box will cut RF by around at least 20dBm, a thick alluminium box will cut reception by around 30dBm.
A 30dBm cut in signal is very significant, its the same as cutting the range to aound 1/30th of what it would be if the transmitter\receiver was in a plastic\wood box.
aminabudahab:
Not really, multiple cheap 433Mhz kits I tried worked without a problem.
It's a sheet metal cabinet of 2.5mm thickness including paint.
You are not doing yourself any favor by placing the radio inside a metal box. While it may work, due to the magic of radio, it is against all recommendations. If you can place the antenna on top of the metal box, you will see a very significant increase in range and reliability.
The attenuation of the signal has virtually nothing to do with the particular material of a metal box as any metal will shield equally well.
It has everything to do with the construction of the box and in particular, how its cover is fitted, whether it makes electrical contact along every seam and what cables penetrate the enclosure.
In general though it simply makes no sense whatsoever to enclose the antenna of the wireless module. If you wish to enclose it in a metal box, you need to mount the antenna on the (outside of the) box itself and you need to use a module which provides the connection for that. If this presents a security problem, usually managed by mounting the box up a pole, you can enclose it in a PVC pipe.
Clearly you need to ensure weather-proofing. If you look around, you will see how this is done in practice, with installations on traffic signs, traffic lights, electrical switchgear, pumping stations and so on.
Paul__B:
Clearly you need to ensure weather-proofing. If you look around, you will see how this is done in practice, with installations on traffic signs, traffic lights, electrical switchgear, pumping stations and so on.
In some applications where I need environmental protection, I mount the radio in a NEMA 4X poly-carbonate box. This provides the water/dust proof enclosure while passing RF.
Thank you all for your input bringing up additional factors to consider in the design but I honestly -and I don't mean to be ungrateful- my original question is still not answered.
I need an RF receiver for my project where I can add additional (ready made) remotes easily and securely.
aminabudahab:
Thank you all for your input bringing up additional factors to consider in the design but I honestly -and I don't mean to be ungrateful- my original question is still not answered.
I need an RF receiver for my project where I can add additional (ready made) remotes easily and securely.
Again, thanks a lot.
linxtechnologies.com makes handheld 8-button remotes with paired RF receivers. Give them a call for the right make and model for your application.
