ZigBee keychain fob, rejoin network?

I’m looking at a solution to opening the door to the apartment building for my son since he’s not big enough to use keys.
I thought of using a keychain fob, and as a test I took one of our IKEA ZigBee remotes outside to see the range but I probably need a repeater.
But when I got inside again the remote did not work and it took a while before it started working again.
Was this a coincidence or do ZigBee devices need time to rejoin the network?

Anyone using a keychain fob in a ZigBee network?

I tried a couple of the Samsung SmartThings Zigbee Arrival Sensors to try and detect the presence of a couple cars, but never had very good success. Not sure that Zigbee battery devices have the kind of wake up and spatial range to be a good solution.

A bit out in left field as an idea for you… but think about a NFC based solution. They have inexpensive NFC wrist bands that he could wear. If you can find a way to get a NFC tag reader somewhere on the outside of the door and then run a flat cable from it back into a ESPHome device driving it…

I don’t like the idea of outside sensors.
I could agree with something mounted outside the window (1st floor) but not at ground level.
I’m quite sure that won’t be appreciated.

I have tried using BT tracking.
It works OK on phones but keychain fobs aren’t strong enough.

I’m hoping I can keep the tech inside.
So RF is an option but I don’t know what receiver to get if I want to use ESP-Home.
Perhaps even IR could work.
Not sure those small keychain IR remotes are strong enough though.

I’m not sure you are going to be successful with the ‘standard’ RF solutions as I don’t think they are spatially aware enough. Example: I believe you don’t want it to trigger when he is inside house.

There a spatially aware RF devices, but I have not found any that I could buy and hack for reasonable price. The ‘gold standard’ devices are the RF keyfobs for cars. The keyfob and the receiver know whether the keyfob is inside or outside the car so you will not lock the keyfob in the car…

I’m still saying look at NFC, ‘low tech’, inexpensive, battery free, relative low worry if he looses it.

Put the NFC reader in the window (have had good luck with NFC reading thru windows and 1/2 inch of solid wood, but doors a bit too thick) .Put a count down timeout on it after he swipes it. If you have a modern iPhone, they have NFC readers built in and apps to read tags, you can buy a cheap NFC tag and test before you build. Home Assistant has some nice NFC support built in, read some of the blog posts about use cases.

Not a keybob form factor for kids for sure, but read this the other day here. The owner of the project did this exactly because the Samsung SmartThings Zigbee Arrival Sensor is not available any more.

Zigbee arrival sensor for car - Share your Projects! - Home Assistant Community (home-assistant.io)

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Back to OP’s subject:
I believe some (or most?) of the smart door locks these days have a feature for BLE detection. Some locks even include a couple of key fobs in the package, for family members who don’t have phone (that does BLE). Would a smart door an option at all?
Just an idea.

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Another idea:
Maybe a 433MHz key fob, along with some 433Mhz bridge to HA?

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I have seen that too.
But this device is always on. I’m hoping and thinking the keychain fobs are powered down and only wakes up when you press the button.
Mainly for battery, but also because I don’t want it to fire all the time. I want it to be “controlled”.
I’m not afraid that it can be pressed when at home and unlocking, that is already covered with wifi detection.
This is just that I don’t want it to open the door too early or when we don’t want it to.

It’s not a lock. It’s the front door to the apartment building leading to the staircase.
But some day I might get a new smart lock here. The Danalock I bought was complete crap.
And I need to replace the internals of the door lock also. This door has some special lock.
It twists 180 degrees, 90 to left and 90 right. It’s spring loaded to maintain 0 degrees at all times.
If I twist left and let go it unlocks the door and key goes back to 0 degrees, and vice versa for right.
That is not compatible with any smart lock that I have found.

That is also a solution (as I mentioned above (RF)), but I don’t know what receiver to get that works well with ESP-Home.
I have read very little about it and some is happy some is not.

Perhaps this was a misunderstanding.
But when I said first floor I meant not ground floor, but one up. So that is 4 meters up.

Your question caught my attention in the first place.
Yes, if you’re away for about an hour, the remote control only switches on when you press the button a second time.
Tested twice.
But you can press again immediately afterwards and then it works.
Key fob 902010/23

I found one of those on Amazon.
It states a range of 10 m, does that sound correct?
I would need to set up a repeater at the end of the apartment and hopefully it will make it.

Does it work OK?

Maybe 20 feet through a brick wall
but then you have to press longer.
Been using it every day for about a month
and ok so far.
But I would take it with a bunch of keys
don’t carry it in your pocket.

20 feet is probably what I need to make it work.
I think we have concrete walls, not sure though.

Probably worth a try.


How do you put it in pairing mode?
I got it today but I can’t pair it, there is no instructions how to do that

There were no instructions included either.
I think the trick was pressing the keys longer.
It actually worked quickly with 2 pieces.

The instructions doesn’t mention pairing.
There is a figure 2 which could explain it, but none of the languages of the instructions refer to figure 2.

Do you mean you pair each button separately?

I still found this in my notes,
I think that’s how I did it too.

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That worked!
Thank you!