My mailbox is in a block of other mailboxes that is fairly far from my home (say, 500m) and out of wifi range without an especially large antenna. I was thinking of making a small battery-powered widget to tell me when the mail arrived and adding it to my Home Assistant (https://www.home-assistant.io/) installation.

Another use may be something like a device that warns if a locked, remote, storage area is accessed. In fact, almost any alarm system that lacks a cellular backup could add one pretty cheaply with this.

Here's an idea about how to start with the mailbox sensor: https://www.twilio.com/blog/iot-mailbox-sensor-m2m-to-sms-fu.... This one sends an SMS when triggered, but you could certainly add it into Home Assistant too.

LoRa WAN and such tech can be very useful for this.

Thanks! I hadn't seen this!

Now that I know this exists, I'm going to use it as a bag tracker to tell me where my baggage went when I travel. I'll probably just get one and use it as my car tracker to tell me when to move for street parking. Or maybe I can just inactive it.

How will you deal with charging? As far as I know connectivity has been a solved problem for over a decade now (on a small scale you could always just get a consumer SIM and use that), but power consumption is a problem. This is why Tile trackers for example use BLE tags and nearby phones instead of just embedding a SIM in their trackers.

The baggage only needs an infrequent duty cycle, right? Like once an hour should do the trick. I don't think I have to attach a large enough battery that I need to not put it in luggage. If it doesn't work out it doesn't.

For the car I have a ciggy socket.

https://www.eatabit.io is built on it. We were one of their first beta clients. We used every M2M carrier previously and Twilio is easily superior in cost & reliability. The cellular data space has alot of problems especially with roaming: cell phones transparently switch between networks but data SIMs have a very limited set of networks they can operate on. If Twilio can get VZW access on these SIMs they will have a very strong product. As it stands, coverage is limited.

I’m interested to hear how the multi-IMSI setup performs globally and how the devices handle the SIM profile switches.