I recently wrote about the Sonoff RF-Bridge – a great device for transferring RF signals from various gadgets to WIFI – well, first things first, I put Tasmota on the RF-Bridge so now, using the free Tasmota Device Manager on it, I can receive information from devices and that gets turned into MQTT by the RF-Bridge.
But which devices? Well, as well as getting to test Itead Sonoff RF products, I somehow I ended up with with two rather nice 433Mhz wireless smoke detectors from Banggood. No brand name that I can see, but they look nice and appear to work perfectly (Itead?). Each puts out a unique code when tested (i.e. the central button held for a second until the green light on the detector illuminates).
These devices run on a standard 9v battery – the manufacturer claims one year battery life from a decent alkaline with audible alarm if the battery voltage dips below 6.8v.
So, the smoke detectors come with a twistable base and by removing that base (no screws) you can change the battery. There is only the briefest green flash in normal operation. When testing or in the case of smoke/fire, there is a full-on green light, the usual audio alarm and telemetry data including a unique code for that device is sent back to RF-Bridge – as far as I can see however, no regular telemetry is sent during normal operation of the smoke alarm.
If there is no-one in the building it would be nice to know that the smoke alarm is actually working – but there it is. The RF-Bridge of course does send regular telemetry but that does not include status for the smoke alarms.
I also received an eWelink 433Mhz Wireless Water Leakage Sensor and a Sonoff DW1 433Mhz Door Window Sensor from Banggood – unlike the smoke alarms each of which use a 9v battery, these other sensors use inexpensive ” 23A” 12v miniature batteries – both come complete with adhesive pads and instructions. I bought 5 batteries for under £3 from Amazon on order – the sensors work a treat – but again I question the wisdom of detecting only a door opening – it might be nice to know when the door closes as well – I’ve ordered another sensor type which whould take a couple of weeks or so to arrive..
The WATER SENSOR turned out to be essential – we just had some flooding and it became essential to know water levels before opening outside doors. The sensor has already saved one carpet soaking and will now be left in operation permanently.