NFC Sticker

The NFC Sticker i use has the following specifications:

• format: Ntag213
• capacity: 144 bytes
• procotol: ISO14443A
• frequency: 13,56 MHZ
• size: 11*21

It is small enough to be glued under the middle belly of a waggon, but sticking it onto the boogie should work too. The middle position is favorable in my opinion.

This way you always know where to position the waggon onto the reader independently of the direction.

Link to buy on: Aliexpress

Data structure

This is "text/json" json structure saved in the Ndef format on the sticker:

{
    "cargo_type": "steel",
    "cargo_max": "42",
    "cargo_amount": "0"
}

Use your smartphone

My Google Pixel 3a smartphone was very handy for debugging and understanding the NFC and Ndef tag after installing this app: NFC Tools from wakdev.

Reading

Here how the NFC data looks like in the "NFC Tools" app:

Writing

Writing any data to the sticker is also very easy. Here an example how i created the tags with the json data shown above.

TODO:

• check if it is possible to remove the quotes for the integers in json repr to save bytes. But i think writing without escaping the string was not possible, hmmmm ...