diff --git a/tools/qrcode_reader.ini b/tools/qrcode_reader.ini
index 46175cb..a541eaa 100644
--- a/tools/qrcode_reader.ini
+++ b/tools/qrcode_reader.ini
@@ -10,11 +10,18 @@ username = admin
 password = eventman
 ca = 
 
+# in the 'event' section you have to specify the ID of the event,
+# the name of the field used to search for tickets and - optionally -
+# the number of chars in the field value that will be considered
+# for the match (limit_field)
 [event]
 id = 1492099112_2612922-3896-9zwsccuvguz91jtw9y6lwvkud11ba7wt
 field = order_nr
 limit_field = 9
 
+# the 'actions' section key: value pairs are used in the PUT method.
 [actions]
 attended = True
 checked_in_by = ${eventman:username}
+checkin_datetime = %NOW%
+
diff --git a/tools/qrcode_reader.py b/tools/qrcode_reader.py
index b52287c..cd9d6e3 100755
--- a/tools/qrcode_reader.py
+++ b/tools/qrcode_reader.py
@@ -22,10 +22,12 @@ import os
 import io
 import sys
 import time
+import json
 import serial
 import urllib
 import logging
 import argparse
+import datetime
 import requests
 import configparser
 from requests.packages.urllib3.exceptions import InsecureRequestWarning
@@ -49,6 +51,8 @@ def convert_obj(obj):
             return True
         elif obj_l in ['false', 'off', 'no']:
             return False
+        elif obj == '%NOW%':
+            return datetime.datetime.utcnow()
     return obj
 
 
@@ -63,6 +67,23 @@ def convert(seq):
     return convert_obj(seq)
 
 
+class ImprovedEncoder(json.JSONEncoder):
+    """Enhance the default JSON encoder to serialize datetime instances."""
+    def default(self, o):
+        if isinstance(o, (datetime.datetime, datetime.date,
+                datetime.time, datetime.timedelta)):
+            try:
+                return str(o)
+            except Exception as e:
+                pass
+        elif isinstance(o, set):
+            return list(o)
+        return json.JSONEncoder.default(self, o)
+
+# Inject our class as the default encoder.
+json._default_encoder = ImprovedEncoder()
+
+
 class Connector():
     def __init__(self, cfg):
         self.cfg = cfg
@@ -119,6 +140,7 @@ class Connector():
 
 def scan(port):
     retry = 1
+    logger.info('trying to connect to %s, please wait...' % port)
     while True:
         logger.debug('waiting for connection on port %s...' % port)
         try:
@@ -133,7 +155,11 @@ def scan(port):
     logger.info('connected to %s' % port)
     ser_io = io.TextIOWrapper(io.BufferedRWPair(ser, ser, 1), newline='\r', line_buffering=True)
     while True:
-        line = ser_io.readline().strip()
+        try:
+            line = ser_io.readline().strip()
+        except serial.serialutil.SerialException as ex:
+            logger.error('disconnected: %s' % ex)
+            sys.exit(3)
         if not line:
             continue
         yield line