Yep, your scenario works and it's completely possible and plausible.

Messages are extremely small and efficient OTA (highly optimized and compressed).

The API is JSON and messages are your own unconstrained JSON object, but they're transmitted as compressed binary. (You can also have a binary payload 'attachment' to a JSON message if you so choose.)

Although everything works fine if the messages are individually in the KB's, that's not the design center because of how we manage memory on our (STM32L4R5) MCU.

Things work most efficiently when the app uses lots of small messages. We buffer them in flash, and power-on the modem at user-settable intervals (or conditions) for upload.

May I please have one clarification:

The 500MB - is that per month - or once for the lifetime of the 10-year cell-"contract" of the card? (if once, how refill once depleted?)

THANK YOU FOR DOING THIS!.

(Also, while at Lockheed, our division was one of the early adopters of Groove. Sadly, we had factions who loved it and wanted to use it and factions who didnt want to change their workflows. -- As the head of IT, I liked it, although it had some quirks... it was too bad we didnt "find our groove" with Groove at the time. But the vision behind it was dope.)

I'm having a hard time finding out the physical dimensions of the cards. Can't see anything in the data sheet about that?

I'd like to know how small a configuration with a Notecard + carrier can be?

For sewing into a kids backpack I think it looks like it will be small enough, but in my mind, putting a tracker inside a shoe would be much better. A backpack is easily forgotten or lost somewhere, but shoes tend to stay with the person. However, to put it in a shoe it'd have to be pretty small.

I think this has what you are looking for, there are a few different cards to choose from but I think they are all in the 35mm square range (https://github.com/blues/note-hardware/tree/master/Notecard)

Long time no chat! Haven’t talked to you since a couple years after Microsoft acquired Groove.

This is really cool, but I don’t see any information on costs if you go over the 500mb of cellular data. Probably missed it, but I did click around a lot trying.

A heads-up: I have been told flash wear can be a problem for such a use case if you always start writing records from the same address after transmitting the buffer. :)

Your raising of your own children is none of my business, but I'm curious: how do you think that being raised while constantly tracked affects the child later on in life?

My personal armchair worry is that it makes them likely to accept a dystopian surveillance society without even considering that it might be problematic.

Sounds like a market: backpack faraday cages and gps spoofing marketed to kids thru animated cartoons on the internet where they find a way to spend their parents money on it.

Why is it desirable to track the kids backpacks? Are they so very untidy that they often get lost?

Where the backpack goes, the kid goes. And the associated battery, case, etc would be easier to put on a backpack than on the kid's clothing.

But what scenario do you want to prevent? I think in case of abduction, the backpack would likely be left behind.

People are unreasonably scared of abductions. The most common use case would most likely be to find a kid that got lost.

Of course, this unreasonable fear of abductions means that a commercial GPS tracker for kids would sell much better if it supported the "abducted kid" use case well, on top of more likely use cases.

Backpacks are a mechanism for transporting your belongings in a convenient bag fashioned with straps such that you may wear it, carry your belongings AND have your hands free.

They would typically be worn by the child, and thus a good indicator of where your snowflake is.

But I want to use this to put on BIKES!

> But I want to use this to put on BIKES!

Are you thinking about theft tracking or some other use case?

Sure. It's a valid case. The problem is that it's probably also easily removable, unless you can hide the gps receiver, the cpu, and the long life battery in the bike itself and the necessary antennas (maybe under a sticker say).

Though I have to say I saw a youtube video recently (sorry to lazy to google it) where someone put an apple tracking device in a bike and was able to locate it after it was stolen.

The best place to put a tracker on a bike is in the fork's steering column, since it's empty and open at one end for antennas. Still, it would take a dedicated device, because it needs to fit in an 1" hole.

I've also thought about building a GPS child tracker, as I haven't found any reasonable/good existing options out there. Tell me if you need any assistance. I am a semi-incompetent full stack developer with IoT experience, reachable at hello at pushdata. io

I know I'm a bit late to the party, but Xplora[1] makes smart watches for children that can be used to call and also has a GPS tracker. They've become very popular here in Norway.

[1] https://shop.myxplora.com/

I used a Samsung SmartThings tracker to track my baby’s stroller.

https://relaygo.com/families/relay ?

Would also be interested.