Update README.md

NfcReaderService.py

@@ -43,7 +43,7 @@ class NfcReaderService:
 
                     if uid_hex == self._last_uid:
                         connection.disconnect()
-                        time.sleep(1)
+                        time.sleep(0.5)
                         self._last_uid = None
                         continue
 
@@ -57,7 +57,7 @@ class NfcReaderService:
                             self._last_write = now
 
                 except (CardConnectionException, NoCardException):
-                    time.sleep(0.5)
+                    pass
 
                 finally:
                     try:

README.md

@@ -4,6 +4,14 @@ This repository contains the tooling around NFC readers/writers.
 
 Currently supported NFC Device: ACR 1252U
 
+## Installation
+
+Make sure you have the apt packages `python3-dev` and `libpcsclite-dev` installed before installing the dependencies from `requirements.txt`.
+
+## Configuration
+
+The root path of the installation (next to `NfcReaderService.py`) needs to contain the `hmac_key.txt`. The correct key can be retrieved from sys admin.
+
 ## Tools:
 
 - card_reader
@@ -17,6 +25,6 @@ Currently supported NFC Device: ACR 1252U
 ## Intended usage
 
 Start `NfcReaderService` on terminals where LAN team needs to verify guest identity, EZGG LAN manager then reads user ID from clipboard.
-`NfcReaderService` may be used as part of a systemd unit, to automate the startup process.
+`NfcReaderService` may be used as part of a systemd unit, to automate the startup process. See service file for additional info.
 
 Run `card_writer` when preparing tickets.

nfc-reader.service

@@ -1,10 +1,15 @@
+# THIS IS A USER-LEVEL SERVICE
+# ~/.config/systemd/user
+# systemctl --user daemon-reload
+# systemctl --user enable nfc-reader.service
+# systemctl --user start nfc-reader.service
+
 [Unit]
 Description=NFC Reader Service
-After=network.target
+After=graphical-session.target
 
 [Service]
 Type=simple
-User=ezgg
 WorkingDirectory=/opt/nfc
 
 ExecStart=/opt/nfc/venv/bin/python /opt/nfc/NfcReaderService.py
@@ -14,5 +19,8 @@ RestartSec=2
 
 Environment=PYTHONUNBUFFERED=1
 
+Environment=DISPLAY=:0
+Environment=XAUTHORITY=%h/.Xauthority
+
 [Install]
-WantedBy=multi-user.target
+WantedBy=default.target