ISO 14443 single (4 byte) and double (7 byte) sized Tag IDs

MFRC522-trigger.py

@@ -47,6 +47,10 @@ def execute_action(event: NfcEvent, tag_id: str):
         ACTION_MAP[action["type"]](action)
 
 
+def tag_id_from_bytes(uid):
+    return ':'.join(x.to_bytes(1, 'big').hex() for x in uid).upper()
+
+
 # welcome message
 logging.info("Welcome to MFRC522-trigger!")
 
@@ -58,11 +62,15 @@ def execute_action(event: NfcEvent, tag_id: str):
 # create a reader
 reader = pirc522.RFID()
 
+current_nuid = ''
+
 current_tag = ''
 last_tag = ''
 count = 0
 polling = False
 
+last_was_7_byte_id = False
+
 # This loop keeps checking for chips. If one is near it will get the UID and authenticate
 while True:
     try:
@@ -74,38 +82,80 @@ def execute_action(event: NfcEvent, tag_id: str):
         logging.debug("Reader loop %d", count)
 
         # scan for cards
-        if not polling:
+        if not polling or last_was_7_byte_id:
             (error, tag_type) = reader.request()
 
             # on error continue and retry
             if error:
-                # logging.info("error request")
+                logging.debug("error request")
+                if current_tag != '':
+                    execute_action(NfcEvent.REMOVE, current_tag)
+                    current_tag = ''
+                current_nuid = ''
+
                 polling = False
                 continue
 
+        # reset after request
+        last_was_7_byte_id = False
+
         # get the UID of the card
         (error, uid) = reader.anticoll()
 
         # on error continue and retry
         if error:
-            # logging.info("error anticoll")
-            execute_action(NfcEvent.REMOVE, current_tag)
-            current_tag = ''
+            logging.debug("error anticoll")
+            if current_tag != '':
+                execute_action(NfcEvent.REMOVE, current_tag)
+                current_tag = ''
+            current_nuid = ''
             polling = False
             continue
 
-        # transform UID into string representation
-        tag_id = ''.join((str(x) for x in uid))
+        nuid = tag_id_from_bytes(uid)
+
+        got_uid = True
+        tag_id = ''
+
+        # Do we have an incomplete UID?!
+        if uid[0] != 0x88:
+            got_uid = False
+            tag_id = tag_id_from_bytes(uid[0:4])
+
+        if got_uid and (current_nuid != nuid):
+            # Activate the tag with the incomplete UID
+            error = reader.select_tag(uid)
+            if error:
+                logging.debug("error select_tag")
+                polling = False
+                continue
+
+            # Get the remaining bytes
+            error, uid2 = reader.anticoll2()
+            if error:
+                logging.debug("error anticoll2")
+                polling = False
+                continue
+
+            reader.halt()
+            last_was_7_byte_id = True
+
+            # Build the final UID without checksums
+            tag_id = tag_id_from_bytes(uid[1:-1] + uid2[:-1])
+
+        logging.debug("Tag ID: " + tag_id)
 
         polling = True
 
         # when we're still reading the same tag
-        if current_tag == tag_id:
+        if current_nuid == nuid:
             # don't busy wait while there's a rfid tag near the reader
+            logging.debug("Sleep!")
             time.sleep(0.1)
             continue
 
         current_tag = tag_id
+        current_nuid = nuid
 
         # execute an action for the reading tag
         execute_action(NfcEvent.REDETECT if current_tag == last_tag else NfcEvent.DETECT, tag_id)

README.md

@@ -173,7 +173,7 @@ my_raspi_host : ok=11 changed=11 unreachable=0 failed=0 skipped=2 rescued=0 igno
   "title": "The root schema",
   "additionalProperties": false,
   "patternProperties": {
-    "^[0-9]+$": {
+    "^[0-9A-F:]+$": {
       "type": "object",
       "title": "Schema holding name and actions for a tag",
       "required": ["name", "ondetect"],
@@ -199,8 +199,8 @@ my_raspi_host : ok=11 changed=11 unreachable=0 failed=0 skipped=2 rescued=0 igno
 
 ```json
 {
-  "1234567890123": {
-    "name": "A very nice tag, triggering 2 actions: playing a playlist and setting the volume.",
+  "01:23:AB:CD": {
+    "name": "A very nice 4-byte NUID tag, triggering 2 actions: playing a playlist and setting the volume.",
     "ondetect": [
       {
         "type": "curl",
@@ -212,8 +212,8 @@ my_raspi_host : ok=11 changed=11 unreachable=0 failed=0 skipped=2 rescued=0 igno
       }
     ]
   },
-  "9876543210987": {
-    "name": "An even nicer tag",
+  "01:23:45:67:89:0A:BC": {
+    "name": "An even nicer 7-byte UID tag",
     "ondetect": [
       {
         "type": "curl",
@@ -233,7 +233,7 @@ my_raspi_host : ok=11 changed=11 unreachable=0 failed=0 skipped=2 rescued=0 igno
       }
     ]
   },
-  "5432109876543": {
+  "AA:BB:CC:DD:EE:FF:01": {
     "name": "This tag is also nice",
     "ondetect": [
       {
@@ -243,8 +243,34 @@ my_raspi_host : ok=11 changed=11 unreachable=0 failed=0 skipped=2 rescued=0 igno
     ]
   }
 }
+
 ```
 
+# Version 2 Breaking Changes
+
+Version 2.x of this software respects single (4 bytes) and double (7 bytes) sized UIDs as defined by ISO standard 14443-3.
+Version 1.x was always assuming single sized UIDs and simply concatenated decimal string representations of each byte 
+(e.g. `1364182229223`). Version 2.x assumes hexadecimal representation of each byte separated by a colon
+(e.g. 4-byte `01:23:AB:CD`, e.g. 7-byte `01:23:45:67:89:0A:BC`).
+
+This incompatability makes config files from version 1.x unusable with version 2.x. For easier config migration a tool
+called `id-convert.py` is provided.
+
+## Config Tag ID Migration Steps
+
+* start `id-convert.py` and rescan all your tags, a file `ids.csv` is written containing a list of old style and new style tag ids
+  ```
+  $ ./id-convert.py | tee ids.csv
+  ```
+* backup your current config
+  ```
+  $ cp config.json config.json.bak
+  ```
+* replace old tag ids with new tag ids in your config file `config.json`
+  ```
+  $ for i in $(cat ids.csv); old=$(echo $i | cut -d '_' -f 1) && new=$(echo $i | cut -d '_' -f 2) && echo "${old} ${new}" && sed -i "s/${old}/${new}/g" config.json; done
+  ```
+
 # Roadmap
 
 * more python unit tests
@@ -255,6 +281,7 @@ my_raspi_host : ok=11 changed=11 unreachable=0 failed=0 skipped=2 rescued=0 igno
 
 # Roadmap done
 
+* ISO 14443 Tag IDs
 * quit with error when config is broken
 * validate config with JSON schema and log a warning when it's invalid
 * multiple actions per event

config.sample.json

@@ -1,6 +1,6 @@
 {
-  "1234567890123": {
-    "name": "A very nice tag, triggering 2 actions: playing a playlist and setting the volume.",
+  "01:23:AB:CD": {
+    "name": "A very nice 4-byte NUID tag, triggering 2 actions: playing a playlist and setting the volume.",
     "ondetect": [
       {
         "type": "curl",
@@ -12,8 +12,8 @@
       }
     ]
   },
-  "9876543210987": {
-    "name": "An even nicer tag",
+  "01:23:45:67:89:0A:BC": {
+    "name": "An even nicer 7-byte UID tag",
     "ondetect": [
       {
         "type": "curl",
@@ -33,7 +33,7 @@
       }
     ]
   },
-  "5432109876543": {
+  "AA:BB:CC:DD:EE:FF:01": {
     "name": "This tag is also nice",
     "ondetect": [
       {

config/config.schema.json

@@ -49,7 +49,7 @@
   "title": "The root schema",
   "additionalProperties": false,
   "patternProperties": {
-    "^[0-9]+$": {
+    "^[0-9A-F:]+$": {
       "type": "object",
       "title": "Schema holding name and actions for a tag",
       "required": ["name", "ondetect"],

id-convert.py

@@ -0,0 +1,67 @@
+#!/usr/bin/env python3
+# -*- coding: utf8 -*-
+
+
+import pirc522
+import sys
+
+
+def eprint(*args, **kwargs):
+    print(*args, file=sys.stderr, **kwargs)
+
+
+# welcome message
+eprint("Welcome to id-convert!")
+eprint("Press Ctrl-C to stop.")
+
+# create a reader
+reader = pirc522.RFID()
+
+found_tags = {}
+
+# This loop keeps checking for chips. If one is near it will get the UID and authenticate
+while True:
+    try:
+        # wait for reader to send an interrupt
+        reader.wait_for_tag()
+
+        # scan for cards
+        (error, tag_type) = reader.request()
+
+        # on error continue and retry
+        if error:
+            # eprint("error request")
+            continue
+
+        # get the UID of the card
+        (error, uid_old) = reader.anticoll()
+
+        # on error continue and retry
+        if error:
+            # eprint("error anticoll")
+            continue
+
+        uid_new = reader.read_id(as_number=False)
+
+        if uid_new is None:
+            # eprint("error read_id")
+            continue
+
+        # transform UID into string representation
+        tag_id_old = ''.join((str(x) for x in uid_old))
+        tag_id_new = ':'.join(x.to_bytes(1, 'big').hex() for x in uid_new).upper()
+
+        if tag_id_new not in found_tags:
+            print(tag_id_old + "_" + tag_id_new, flush=True)
+            found_tags[tag_id_new] = 1
+        else:
+            eprint("Already got it! " + str(len(found_tags)))
+
+    except KeyboardInterrupt:
+        eprint("Shutdown!")
+        break
+    except Exception:
+        eprint("Unexpected exception '%s' occurred!", str(sys.exc_info()[0].__name__))
+        break
+
+reader.cleanup()