I need to replace my iSmartAlarm smart home alarm system as the vendor has decided to ditch the product. So I’m looking for a wireless system which can easily be integrated with HA (e.g. arming the system when the last person leaves the house, disarming it when the first person arrives at home).
Can anyone recommend a wireless alarm system which works well with HA?
Yale Smart Living - Home Assistant (home-assistant.io)
I use the above with a Yale Smart Home Alarm (not the sync version which might be better)
hope that helps
Thanks for that - the Yale Sync system looks interesting.
Thinking more about it, is there a system anywhere which can send intruder alerts to HA?
There’s a load of videos on YT about making a DIY system with HA if that’s of any interest? some easier than others. 
Hmmm…that sounds interesting. The idea of a completely configurable (and low cost) solution does appeal.
I also just found this, which looks like an excellent starting point using low cost components:
The only scary part was flashing Tasmota on the Sonoff RF Bridge, but I see that you can buy Tasmota-flashed units on eBay so maybe this is worth a try. I like the idea that I can start with about £35 of hardware to test the concept
a good read - thanks. I dont think you need to go to the the hassle of flashing tasmoto though. I believe (I’ll see if I can find the links to confirm) the sonoff USB stick works with both ZHA and zigbee2mqtt without and flashing - see here: SONOFF ZigBee CC2531 USB Dongle Sniffer Board Packet Protocol Analyzer Module UK | eBay
couple that with the sonoff motion/door sensors and that may get you what you need. e.g. SONOFF SNZB-03 ZigBee Smart Motion Sensor Home Detect Alarms& Base Holder UK | eBay
I use a different type of usb stick but use the sonoff motion/door sensors all over the house for various things. HA opens up all sorts of opportunities
Thanks for that. Do you know if that Sonoff USB stick would work with the same range of generic 433MHz devices as the RF bridge? I just remembered that I still have a bunch of motion and door sensors from an old Response alarm system (the control panel died) - all 433MHz - so I was hoping to use those and save myself even more cash.
Also, would the USB stick be a like-for-like replacement for the RF bridge - in terms of being able to receive/learn 433MHz codes and also transmit them?
pretty sure the bridge will have better range (sure the original tasmota flashing vid mentions this) - but if you have devices that can also act as zigbee routers (I think a lot of lightbulbs are routers and I have a couple of the ikea zigbee routers) then that might not be as much of an issue.
your old sensors might work but there may not be the right drivers etc. one can but try. I have bits from 2 broken alarms (cant remember the makes) but some work but others I just can get connected.
FYI im no expert - but i hope this helps
If you havent seen them try this: It Works! Sonoff Zigbee & ZHA Home Assistant Integration +Aqara + Zemismart Tuya - They all work! - YouTube and this the official vid from sonoff - How to set up ZigBee with Home Assistant? - YouTube
FYI - If you do go the USB stick route it is pretty much essential that you also get a USB extension cable - they are prone to interference when too close to other electronics. I have mine at the end of a 1.5m extension mounted up on a shelf far away from anything else electronic. the main issue I had before doing this was getting anything at all to bind.
The Zigbee USB stick does not do 433 Mhz.
Ah OK thanks. It sounds like the Sonoff RF Bridge would give me more options for connecting legacy switches (e.g. my existing Response 433MHz sensors)
I was interested to see in that Youtube video that the HA device reported the battery level of each connected sensor. Am I likely to get that if I use the Sonoff RF Bridge with generic 433MHz devices, or is that a Zigbee feature?
think thats a zigbee feature and if you use ZHA of zigbee2mqtt you should get access to it. based on experience dont try and do what you want to do properly first time/in one go. I got into a mess and messed up my whol;e config. after the reintall from backup I fired up a separate install of HA and tested what i wanted to do with zigbee in that. then i migrated into my live instance.