End of last year more by accident I stumbled upon an article presenting a dog tracker. Well, I do not even have a dog. What caught my eye was more the fact that it should work without the usual transmission techniques like WiFi, Bluetooth (which would be even too short ranged) but also noch cellular radio involved, which is usually the case here. So how could such a pet tracker transmit any signal to somewhere? Since I studied communications engineering and am a Radio Amateur for more than 30 years, equipped not just my car with telemetry, I was (and still am) fascinated and thing this might be the next step in the real Internet of Things (IoT). If you want to place sensors everywhere (guess if I already have connected my coffee machine), it is so useful, having a technology that connects to gateways all over Europe (with limits outside of Europe due to regulations for the 868MHz band) that are in range of up to 15km. This means, if just some people in your area are willing to erect a gateway, then you have a connection. Very important here also: Due to the very low battery consumption, these things last over months. So you might have a pet tracker which is small in size, just needs to be recharged every three months and get your dog even a different country (as long it is within reach of a gateway). The ideas of what to do are limitless. The data you send is encrypted, so you don’t need to worry about that. Opening a garage door is as possible as checking your door status in your holiday home (which doesn’t need to be connected to the internet as long as you have a gateway in range).
I fiddled around with so many types of sensor-transmitters, the ones with Bluetooth, Z-Wave, Wifi, plain 433MHz and more. But without the need to have an own gateway and have a use also being on vacation (think of a luggage finder when you are waiting on the belt on the airport for an hour), this is the way to go big. I started off with buying The Node from The Things Network (TTN) as an example piece to get in shape with this stuff. If you dare to use the Arduino environment to program a bit, you are done within minutes to accomplish what you wanna do. I let this “Thing” simply transmit some data from its sensors (battery state, temperature, motion) in intervals. More important for me, which gateways would collect those data and push it forward to the Internet, then letting the TTN forward that immediately to my own server and finally letting this one forward it to my Apple watch, so I could see how (fast) it would work. Well, it does not even need a second, so even time critical data could be transmitted.
What am I going to do with this? Since I just like to be able to transmit some data from A to B, my main intention is already solved. I will quite likely test my “Thing” when going flying in lower altitude (around 1000m/3000ft) and see if my signal get’s caught from a gateway. Since the transmission power is some Milliwatts (mW), I do not expect any interference in the plane (I already have a WiFi connection in the plane anyway). So I will carry my “Thing” with me and see what I can imagine and the realize. There might even be opportunities for Insurances or Legal Services. I’m quite optimistic here.