Zigbee Key Fob for Hotel Room Circuit Control: Alternatives to RFID Cards?

Hi,

I need to install a device used in hotels, switching off certain circuits when the user leaves the house. Hotels use hotel switches in the form of cards, RFID cards, magnetic cards. The user has them clipped in together with the room keys. Upon entering the room, he inserts the card into the slot. Circuits (AC, TV etc.) are switched on. When leaving to lock the room, the user removes the card from the slot, disconnecting the circuits.

As I have Zigbee, it would be more convenient to use a key fob that would be polled periodically by the network . Advantages , small size (with keys) and no need to place in the slot. WiFi solutions are power hungry. BLE would be ok but I have no way to integrate .

Maybe a colleague has an idea or has linked some inexpensive solution.
The idea is to cut the circuit when the user leaves the room. I know I could do detection using a door sensor + PIR, but maybe there are some low energy key fobs that would take care of the issue. In the 21st century, I don't want to put a large card under the keys. Especially as there is zigbee 3.0 (tuya) at home. The advantage of a physical rally is the reliability and wired connection. There are UHF RFID solutions. The usb programmer I have, but the readers are expensive. RFID on the lower bands require proximity, and I would like to eliminate this (it appears in the room brelko, the sytem detects it by itself, without user action)

I would be grateful for suggestions of sensible, viable solutions / products.

Regards .

At what time after leaving the room should "certain circuits" be switched off ?
How big is the room ?

austin007 wrote:

off certain circuits when the user leaves the house.

Immediately, because this is how cards and keys work, I myself am curious about such a solution, because for the time being I am going to make a switch on the key from the front door, the only sensible and convenient solution at this time

yanes wrote:

Immediately

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No radio solution will work immediately. The presence of a key fob can be detected quite quickly. Its absence can be detected at the earliest after 15-30 sec.

That's enough, seconds don't play a major role here. Now what do you propose?

You did not answer the question of how big the room is.

The size of the room doesn't matter at all, you can see that you don't understand what the author of the post is referring to.

austin007 wrote:

Hi,
As I have Zigbee it would be more convenient to use a key fob that would be polled periodically over the network . Advantages , small size (with keys) and no need to place in the slot. WiFi solutions are power hungry. BLE would be ok but I have no way to integrate.

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My guess is that it is all about detecting the presence of the key fob/user in the room.

TvWidget wrote:

At what time after leaving the room should "certain circuits" be switched off ?
How big is the room ?

.

Usually such devices have an adjustable delay or a fixed approx. 30-60 sec - hold after card removal. Once inserted, the circuit is immediately closed. The room is approx. 3mx3m but this is rather only relevant for PIR/US/MW detection.
The switch-on time does not play a major role here - up to, say, 30s is ok. Lighting circuits will not be switched on, but if the delay were shorter (a few sec), the functionality could be used to automatically switch on the lighting (when needed).

As far as radio solutions are concerned, in my opinion with such a small room a BLE key fob would be most convenient. With a broadcast period of 1 sec, the chances of it not being detected for 30 sec are negligible. Of course, there could always be strong radio interference lasting those 30 sec. The question is whether the very occasional detection of absence will be threatening.
However, the radio solution will be hardly selective. In practice, the user will already be uprooted when approaching the door from the outside. I don't know whether this will not be disruptive.
Then there is the security aspect. There are solutions using user authentication that are very difficult to bypass. You have not written whether this is relevant in this case.

TvWidget wrote:

As far as radio solutions are concerned, in my opinion with such a small room a BLE pendant would be most convenient. With a broadcast period of 1 second, the chances of it not being detected for 30 seconds are negligible. Of course, there could always be strong radio interference lasting those 30 sec. The question is whether the very occasional detection of absence will be threatening.
However, the radio solution will be hardly selective. In practice, the user will already be uprooted when he approaches the door from the outside. I don't know if this will not be a nuisance.

Detection through the door should not be a problem. I don't associate such BLE key fobs that don't require user interaction. Something always has to be pressed there I think. And then there's the receiver. Do you have an idea for a BLE receiver ?
As for the unreliability of detection , it loses some functionality, but it's not an alarm system so it's not critical. It's not an alarm system, so it's not critical.

BLE devices, as a rule, periodically send information about their existence. Nothing needs to be pressed. If security considerations are not important then any beacon can be used. The cheapest ones admittedly have a rather low transmitter power. With a 3x3m room, however, this should not be a problem.
I don't know what exactly you expect from the receiver and how you want to connect it to these "certain circuits" ?
You wrote in the section " ESP8266 and ESP32 and IoT". Acct ESP32 can receive BLE broadcast frames.

Keys usually hang by the door and you can confidently limit the detection area to a radius of 1m from the receiver. ESP32 has BT in the structure so you could indeed write under it. However, I have not yet worked out BT support in ESP32. Security considerations are less important, but I would still prefer to only recognise registered devices (e.g. MAC_adr) I have something like the ITag Tracker key locator. He has a button to share, it is aesthetically pleasing and not large. The question is whether it would be suitable.

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austin007 wrote:

Security considerations are less important, but I would still prefer to recognise only registered devices (e.g. MAC_adr)

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Most tags have a fixed unique MAC address. The standard also allows dynamic addresses. These are used, for example, in the Android system. It is all about user privacy considerations.
It is relatively easy to impersonate a device transmitting a fixed frame. It is similar to RFID with a fixed ID. As I have already written in more demanding systems, connection mode and authentication using encryption, passwords etc. are used.
A classic beacon is constantly broadcasting. These 'anti-lost' devices probably work like that too. However, there is no certainty. Sometimes a different functionality is used. A connection is established with the tag and maintained. When the connection is broken, an alarm is sounded. The connection does require broadcasting. However, this can only be done by pressing a button.

Thanks . From what I have read there is iBeacon technology, but more expensive because it is for Mac. There is an alternative , opensourc but I have not found cheap , convenient devices . I have read and found some solutions on github to support the antlost- tag I have. It works as a server. Two-way transmission. I just don't know if such a tag by itself will connect to a listening ESP32 (after authentication). So far it's a rekonensans, but the chances of implementation are there. I have no experience with BT/BLE and it's not that trivial. Fortunately there are some repositories on GH.

As a rule, devices with a BLE interface such as a sensor, key fob, etc., periodically (e.g. every 1 second) sound themselves, i.e. send a broadcast frame. Turning on BT scanning searches for all devices that are in the vicinity. In the case of the ESP32, an event will occur after each frame is received. In its handling, you can retrieve the contents of the frame (a sequence of bytes). Among other things, there will be the unique MAC address of the sender.
Only specialised beacons allow authentication. Simple ones transmit a fixed frame and that's it.
Hardware-wise, an iBeacon is a simple beacon. The content of the transmitted frame is only what Apple came up with. In the case of the ESP32, it doesn't matter.

One question. How many people are to use the room. And how often are they supposed to change. Because if it is to be 1-2-5 regular people then maybe by BT authentication on the phone. You pair the ESP device with the phone. Phone comes into range-connection occurs(lights come on, door opens)-ESP loses range (cuts off light, closes door) BT activation on phone is 3-5 finger movements. The downside is a sudden lack of power on the phone. The only other option is a bicon with BT transmission encryption.

Edit.
If you have access to wifi then you will embrace this with sonoff mini, RPI3/4 and HA switches

Szaryczlowiek83 wrote:

Because if it is to be 1-2-5 regular people then maybe by BT authentication on the phone

BT yes, but not on the phone. This is supposed to be a device not assigned to the teleofn etc and dependent on it. Hardware solution. Ew RFID tag UHF 13, 56Mhz. I usually insert keys in the door lock from the inside. According to the info, such RFID has a range of approx. 30 cm. A receiver in the wall near the handle would do the job. However, such a BT beacon which broadcasts every 1 sec would be a good solution. Especially as I have one. Just a matter of a receiver on the ESP32, which has natively BT

You have the ESP 32-wroom tiles. With wifi and BT only it costs a bit🙂