Heya
I am looking for an inexpensive button solution for my OH installation. The purpose is a door bell - so I don’t need anything fancy. The last thread about this topic concluded with a Hue solution.
I’d like to give the Amazon Dash button a try - but I was not able to find out if I can still activate and use them (Germany) I get mixed messages in the forum.
I would not like to go for Zigbee or Hue (no receiver) BT might be possible (range) and the button needs to be self powered
Self powered may also be with a battery. Enocean is a nice eco system but does not necessarily fall into the category “inexpensive” 
So maybe give a chance to Zigbee2MQTT. About 5$ for CC2531 USB dongle, 8$ for single Xiaomi button. Button reports single, double and long clicks. I’ve got 5 such buttons in a flat and works like charm.
I am not sure if you meant no Zigbee or Hue specifically, or no receiver in general, but if the latter case I am not sure how you plan on receiving the signal?
Assuming you meant the former, another alternative are 433mhz buttons. They are super cheap (some $3-4 only, even in qty. 1, shipped! on AliExpress) but of course you will need a receiver.
There are lots of 433mhz gateway/receiver solutions, one that is recommended a lot around here seems to be RFXCOM however I honestly found that quite overpriced for what it is. So if you are as I suspect a “value conscious” let’s say (aka cheap 
) person as myself, and you don’t mind a little DIY (I do see you tagged this with DIY in fact) another alternative perhaps (and what I use) is Open MQTT Gateway.
Get yourself one of uC that are supported (uC are lots of fun anyways) plus some 433mhz transmitter and receiver pair (make sure “superheterodyne” type!) and then put it together and flash Open MQTT Gateway (OMG). Step by step instructions on this over at OMG docs are pretty easy to follow, IMO.
Of course this presumes MQTT usage/preference also, but many people going this way now (not sure how you feel about it). But all this hardware is only handful of dollars.
As an added bonus, OMG also supports BLE, RF, and other protocols should you decide to add them later. Of course you need radios for those, but they are also readily available and inexpensive.
Another bonus, you can stick these buttons anywhere, without needing to cut into walls nor otherwise mess with mains wiring, etc. Always wanted another switch on the other side of the room? No problem… 3 button scene control? You get the idea…
I will be honest, these 1/2/3 gang 86mm (I think?) square 433mhz wall buttons do feel a little “cheap.” But they do work and are inexpensive. Not the greatest range in the world either (they run on coin cell). But batteries are cheap, readily available, and last a long time. However the OMG can be moved anywhere you have an Ethernet outlet, so in my case I will be moving mine to a more central location in the home, as right now it is in the back corner and sometimes struggles to pick up signals from front door area (which is essentially opposite corner of home for me).
There are also some “round” 433mhz buttons which are a little nicer looking / feeling and probably more appropriate for your doorbell (or whatever else).
On the config side, you basically use OMG to sniff the signals they put out (you can see the values with any MQTT monitor, I just use mosquitto_sub -h <broker IP> -t +/# -v) then set up OpenHAB to do whatever you want based on those. I suppose I should write up a little guide on that. Let me know if anyone is interested and it might motivate me to do so.
according to this post there are users that were able to activate the button in June 2020.
Thank you for your suggestions
@emka
My reason - why I do not want to go for zigBee was initially - just laziness. I have a very mature OH setup which is an ongoing project since 2013 (i.e. I’ve spent a lot of time on it) and it was always a pain to get a new eco system running.
But it might actually be worth it anyway. A lot of stuff is based on zigBee these days… and inexpenisve it is indeed. Which buttons did you have in mind? The Aqara or the Miija ones?
@TRS-80
433Mhz is an interesting idea. I have it running for a few plugs via Pilight and a raspi- let’s see if the range is good enough. I don’t mind a bit of DIY and most of the setup is already done… so I might give it a try. Do you have a link to the buttons?
Your openMqTT suggestion however looks sweet and I am sure the community will appreciate a little from zero to hero guide.
My usecase is simple. Press a button -> trigger a rule.
@Wolfgang_S
Thank you for this link - looks indeed promising. I can get 4 Dash buttons for ~20€ also not too bad
So I have 3 possible solutions to investigate further.
Some weeks ago I also looked for an alternative for my Dashbuttons, because it did not seem to be a long term solution.
I went for an Ikea Tradri wireless Dimmer (kabelloser Dimmer). It’s a nice device with two buttons and long-click-support. It costs only 5,85 EUR in Germany. It uses zigbee and I’m using zigbee2mqtt with a cheap usb-dongle, because the native zigbee-Binding does not yet support it.
The battery consumption is low and it also reports the battery level via zigbee.
Hello
After evaluating the different options I’ve devided to go for Zigbee after all. It might be less pain than initially thought. I’ll keep you posted if I regret this decision 
For now I have to wait till Ali delivers. I’ve decided to do the flashing myself as I wanted a CC2531 with Antenna which I got for about 6€
Good choice
I hope you already ordered additional programmer - it is needed to refalsh CC2531 to Zigbee2MQTT software.
If the CC2531 has been flashed with the zigbee2mqtt firmware once, the firmware can then be changed or updated via USB without a programmer. This works with zigpy-znp (https://github.com/zha-ng/zigpy-znp).
I ordered a preflashed stick and so did not need a programmer.
I recommend the source routing firmware from Koenkk by the way.
I did not… this description led me to believe that the programmer is just convenient - but with a little fiddle you get the firmware onto the stick with a raspi as well.
That’s true DIY spirit! Good choice! 
A bit late to the party I still want to chime in - I also think zigbee is a good choice, with many options to choose from (I have both the Xiaomi and Tradfri buttons). I recommend against dash buttons. While they are cool they are also extremely slow.
Once you have zigbee you will probably soon use the added possibilities and also get some cheap thermometer/hygrometer combos, osram plugs (can work as repeaters/extenders), motion detectors, …
At least that’s what happened to me 
Here is some cheap 433mhz self powered buttons,
Solar one
Cinetic one
Links are affiliated.
The first one is easier to integrate. For the second one I had to specify a special rcswitch protocol.
The serial bootloader is a part of Texas Instrument’s Z-Stack SDK and should be available even if you haven’t flashed one of Zigbee2MQTT’s builds of Z-Stack yet. This obviously won’t work if your stick was shipped to you completely erased, since it will have no bootloader. Think of it like an Arduino.
So here we go.I received the stick and buttons a few days ago. Today I did sat down and started with the flashing.
I did not order the programmer but I connected wires from the Stick to the GPIO pins of my raspi. There was a first fail: I used a Raspi 4 and somehow the Pins from the tutoial and the Raspi4 did not really match. After a while I gave up and used an Raspi2. Here the flashing worked like a charm.
Then I got the zigbee2mqtt running and hooked it up with my mosquitto.
Next I paired two Xiaomi Buttons and worked out how to capture the MQTT Message via in Item.
String Button2 {mqtt="<[mosquitto:zigbee2mqtt/0xxxxxxxxxb146/click:state:default:.*]"}
Then I can use a switch statement to do whatever I like when a single, double or long click comes in.
This took me about 3-4 hours. Where at least half of the time was wasted by geting the flashing done on the raspi4.
The runner up was: getting my item right. The rest was downloading time, reading up, rebooting etc.
Total cost with the stick + antenna and two buttons: ~22€ compared to the Dash buttons - a much better deal.
So thanks to you guys for convincing me
Well done on getting this working! My first time took at least this long too…!!
This is syntax using the MQTT v1 binding - just bear that in mind when looking at examples online, as the v2 binding has been around for some time!