A closer look at the Got-It Bluetooth tags

Jan 8, 2020
Categories: Hardware
Tags: bluetooth

Intro

When I first heard of the Got-it Bluetooth tags, I just had to order a preview set.

Those are active Bluetooth Low Energy beacons, embedded into a thin and flexible sticker, including battery. The proposed use case is asset tracking in commercial settings.

  • They are 28mm x 76mm x 0.75mm
  • Battery life is supposed to be one year
  • Waterproof, flexible
  • A preview set containing 10 stickers costs 99$, they plan to get the price down to $1/sticker
  • Some pictures provided by Got-It here

How I received my labels:

You can read all the details in the Hacker news launch thread and on their website , all the infos in this post are from those two sources.

I have successfully tested the tags. Each tag contains an unique ID, which can be registered to an account using their app (which currently only exists for iOS).

The way asset tracking is supposed to work: even though the tags are short range, as more people have the app installed their phones will provide good coverage of an area, and report the locations of all tags to the server. The tags themselves don't have GPS or location capability.

App screenshot:

Electronics

The tags seem to consist of three basic layers when torn apart, from top to bottom:

  1. Cyan film with electronic print on its back side (laminated polypropylene and PET)
  2. Ultra-thin Lithium primary battery
  3. A black foamy adhesive sticker (polyurethane foam)

There are two different electronics circuits on the labels: a NFC tag on the left side – for reading out the serial number with the app – and a BLE circuit. The BLE circuit consists of a microcontroller, an oscillator crystal and some SMD resistors/caps. On the picture below, you can also see the Bluetooth antenna (square wave shaped). I am not sure what the comb-like print structures are for. The serial number at the top right of the print reads Reelables v0.3E, and the BLE microchip has NS2810 CAAAA0 1919A0 written on it.

Back side of the blue film, showing the print:

BLE circuit closeup:

Battery

Battery on the black foam adhesive, white stuff is some paper that got stuck to it:

Battery voltage:

NFC

The NFC chip is a NXP NTAG213F. Reading it out with a RFID scanner app on my phone gives:

-- NDEF ------------------------------

# NFC data set information:
NDEF message containing 1 record
Current message size: 52 bytes
Maximum message size: 142 bytes
NFC data set access: Read & Write
Can be made Read-Only

# Record #1: URI record:
Type Name Format: NFC Forum well-known type
Short Record
type: "U"
protocol field: [none]
URI field: https://app.got-it.link/label/?hw=2&id=00010147
Payload length: 48 bytes
Payload data:

[00] 00 68 74 74 70 73 3A 2F 2F 61 70 70 2E 67 6F 74 |.https://app.got|
[10] 2D 69 74 2E 6C 69 6E 6B 2F 6C 61 62 65 6C 2F 3F |-it.link/label/?|
[20] 68 77 3D 32 26 69 64 3D 30 30 30 31 30 31 34 37 |hw=2&id=00010147|

So each tag just contains an URL with its serial number.

Conclusion

I think it is fascinating that they managed to put an active bluetooth beacon into such a form factor, with a (claimed) year of battery life. The current version is still a bit clumsy, because the three layers are not very homogenous and tend to disconnect when you try to bend the sticker too much.

In 5 or 10 years we'll probably have those with long range, low power radio communication (LoRa or 5G), GPS and power harvesting (which I find a little creepy).

Even the current version reminds me a lot of the “invisible target tracking tags” from the Blake and Mortimer cartoon “The Time Trap”: there, such tags are used to track enemies, and target weapons at them.

Radio beacons in "The Adventures of Blake and Mortiner: The Time Trap"


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