I’m interested in converting my house sensor network into one running on LoRa.
The background to this is the sad demise of the Nottingham company WirelessThings from whom I had purchased a number of house sensors. These were small devices transmitting over 868MHz with a variety of ‘personalities’ including temperature, flood, magnetic, on/off, light and so on. I had them scattered around the home, including a water detector on my back fence where the seasonal flooding from the local river first enters my property.
The head end was a simple USB stick plugged into one of my SBCs running NodeRED. This collected incoming radio signals using a text protocol called ‘LLAP’ and converted them to MQTT, sending them on to a variety of end points such as alerting my mobile phone when floods were coming in. As the devices went into a configurable sleep mode, the button batteries lasted years without replacement. I even had a separate NodeRED flow that handled battery level to alert to replace batteries. They were useful in a number of ways:
- knowledge of battery state
- ability to ‘talk back’ to a sensor
- transmission over relatively large distances
- simple, configurable and multiple sensors using a small form factor enclosure
- different sensors encoded values into a similar-length text string (12 bytes)
All that has finished with the closing of that company, so I have been toying with using a LoRa gateway from someone like Pycom, or purchasing a full LoRa gateway and connecting this to The Things Network and thence back to my servers. Cost is playing a significant part as I can’t really afford three- or four-figure sums for my electronics hobby. The Pycom LoPy running MicroPython looks like a good alternative (even if it cannot act as a true LoRa gateway due to lack of multiple channels) so I may wait for that to stabilise and then work from there.