Snapmaker U1 RFID Programming
The tags required are NTAG215 and NTAG216
NTAG213 will not work due to the storage size limitation.
This app uses the OpenSpool format which was added in the SnapmakerU1-Extended-Firmware you must install this firmware to write your own RFID tags.
The extended firmware adds many features and fixes which you can read about HERE
https://www.youtube.com/watch?v=71oCmjIfqTc
The android app is available on google play
The tag format is a simple NDEF application/json record which is in the OpenSpool format.
{
"id":"0",
"protocol":"openspool",
"version":"1.0",
"brand":"Snapmaker",
"type":"PLA",
"subtype":"Matte",
"alpha":"FF",
"color_hex":"0000FF",
"min_temp":190,
"max_temp":220,
"bed_min_temp":50,
"bed_max_temp":60,
"diameter":175,
"weight":1000
}
The following document explains the format of the official snapmaker tags.
U1 Tag Protocol
Currently we can read and write to the MIFARE Classic 1K tags with the derived keys the printer expects but we cant validate the filament data with a RSA signature due to the private key snapmaker uses.
We can bypass this signature check which requires firmware modification.