Noob Q : Motion Detection, Lorawan & Battery Power

  • Hi Folks,

    I'm rather new to IoT development and I have a few questions about a new project.

    I'm building a squirrel box for the garden as a project with my 8 year old son. He would love a way of sensing if there is actually anything in the box, so I thought a battery powered motion detector would be ideal. Obviously if it is battery powered then Wifi is out of the question, so we have to go with Lorawan to get the data out.

    So, my questions are :

    1. Can I use the M5Stack Atom DTU LoRaWAN Kit do do this and would it be easy enough for us to figure out how to do it? I have some coding skills, but it is mostly just coping & pasting from the internet!

    2. I have seen that there isn't a motion sensor onboard, but I hope that I can add on using the Grove port. Is this just plug & play?

    3. Are there any other sensors built into this device which may give us other interesting information which we can report? The more info we can report, the more interesting it will be. I have a VPS running Grafana which I was hoping to utilise for graphing the output if this is possible, with a panel showing if there is something in the box.

    4. Can I run this off a battery? Since it is going to be screwed into a box, up a tree, we really need this to run for months or longer on battery power. Would it run from a phone charger USB battery pack and give this kind of usage time?

    Any help or pointers on this would be much appreciated.


  • If you're monitoring motion then that PIR has to be powered full time. I think even a large USB battery might only get you a few days. Solar is a possibility, but now you have to include a battery plus charge circuit ( you can buy the charge circuit preassembled).

    For an experience person this project is of low/moderate complexity. For you it would be a great learning experience and will likely require quite a bit of work.

    Make sure there is a Lora receiver somewhere close by (a few blocks).

    WiFi is pretty lousy but if you have a strong signal where the box is, it saves you from buying a lora device. and would be good sources for things including solar parts.

    You might be able to rig up a trip wire or something to flip a switch, which wakes the unit, it transmits, and then sleeps. You would have to figure out if M5 can sleep and be re-awakened with a switch. I'm new to the platform so I don't know if it can do that. This is probably not the best option but who knows.

  • Hello @iot
    You might want to check for the battery output/voltage before deciding whether to use it or change to a longer lasting battery supply or even a switch. Bear in mind that the weather conditions such as heavy rain should be taken into consideration as there are devices and wires involved because you don't want to shock the device/battery. Another tip is that the material of the box should withstand any weather and temperature. All the best in your project!

    @david-bethesda mentioned Solar parts, which is a good idea too.