Fixed uid output. Also fixed line endings (sorry).

software/src/mfrc522/main.py

@@ -1,44 +1,45 @@
-from mfrc522 import MFRC522
-import utime
-
-
-def uidToString(uid):
-    mystring = ""
-    for i in uid:
-        mystring = "%02X" % i + mystring
-    return mystring
-
-def main():
-    reader = MFRC522(spi_id=1,sck=10,miso=12,mosi=11,cs=13,rst=9)
-
-    print("")
-    print("Please place card on reader")
-    print("")
-
-    PreviousCard = [0]
-
-    try:
-        while True:
-            reader.init()
-
-            (stat, tag_type) = reader.request(reader.REQIDL)
-            #print('request stat:',stat,' tag_type:',tag_type)
-            if stat == reader.OK:
-                (stat, uid) = reader.SelectTagSN()
-                if uid == PreviousCard:
-                    continue
-                if stat == reader.OK:
-                    print("Card detected {}  uid={}".format(hex(int.from_bytes(bytes(uid),"little",False)).upper(),reader.tohexstring(uid)))
-
-                    PreviousCard = uid
-                else:
-                    pass
-            else:
-                PreviousCard=[0]
-            utime.sleep_ms(50)
-
-    except KeyboardInterrupt:
-        pass
-
-if __name__ == "__main__":
-    main()
+from mfrc522 import MFRC522
+import utime
+
+
+def uid_to_string(uid):
+    mystring = "0x"
+    # The mfrc522 lib returns all tested uids in inverse order
+    for i in reversed(uid):
+        mystring += "%02X" % i
+    return mystring
+
+def main():
+    reader = MFRC522(spi_id=1,sck=10,miso=12,mosi=11,cs=13,rst=9)
+
+    print("")
+    print("Please place card on reader")
+    print("")
+
+    previous_uid = [0]
+
+    try:
+        while True:
+            reader.init()
+
+            # For now we omit the tag type
+            (stat, _) = reader.request(reader.REQIDL)
+            if stat == reader.OK:
+                (stat, uid) = reader.SelectTagSN()
+                if uid == previous_uid:
+                    continue
+                if stat == reader.OK:
+                    print(uid_to_string(uid))
+
+                    previous_uid = uid
+                else:
+                    pass
+            else:
+                previous_uid=[0]
+            utime.sleep_ms(50)
+
+    except KeyboardInterrupt:
+        pass
+
+if __name__ == "__main__":
+    main()