diff --git a/modules/helper/ble_gatt_server.py b/modules/helper/ble_gatt_server.py
index 3662b909..aff1f2a5 100644
--- a/modules/helper/ble_gatt_server.py
+++ b/modules/helper/ble_gatt_server.py
@@ -1,6 +1,7 @@
 import asyncio
 import json
 import re
+import base64
 import traceback
 import datetime
 
@@ -50,6 +51,10 @@ def tx_characteristic(self, options):
     def send_message(self, value):
         self.tx_characteristic.changed(bytes(value + "\\n\n", "utf-8"))
 
+    def atob(self, matchobj):
+        r = base64.b64decode(matchobj.group(1)).decode()
+        return f"\"{r}\""
+
     # receive from central
     @characteristic(rx_characteristic_uuid, CharFlags.WRITE).setter
     def rx_characteristic(self, value, options):
@@ -90,19 +95,18 @@ def rx_characteristic(self, value, options):
         ):
             # remove emoji
             text_mod = re.sub(":\w+:", "", self.value.decode().strip()[5:-2])
-            # add double quotation
-            text_mod = re.sub('(\w+):("?\w*"?)', '"\\1":\\2', text_mod)
+
+            # decode base64
+            b64_decode_ptn = re.compile(r"atob\(\"(\S+)\"\)")
+            text_mod = re.sub(b64_decode_ptn, self.atob, text_mod)
+
             message = {}
             try:
                 message = json.loads("{" + text_mod + "}", strict=False)
             except json.JSONDecodeError:
                 app_logger.exception("failed to load json")
-                app_logger.debug(self.value.decode().strip()[5:-2])
-                app_logger.debug(text_mod)
-                try:
-                    message = json.loads("{" + text_mod + '"}', strict=False)
-                except json.JSONDecodeError:
-                    app_logger.error("failed to load json (retry)")
+                app_logger.exception(self.value.decode().strip()[5:-2])
+                app_logger.exception(text_mod)
 
             if (
                 "t" in message
diff --git a/modules/logger/logger_fit.py b/modules/logger/logger_fit.py
index 0927ac89..0b694f73 100644
--- a/modules/logger/logger_fit.py
+++ b/modules/logger/logger_fit.py
@@ -396,7 +396,7 @@ def write_log_python(self):
             struct.pack(
                 struct_def,
                 end_date_epochtime,
-                int((end_date - start_date).total_seconds()) * 1000,
+                (int(end_date.timestamp()) - int(start_date.timestamp())) * 1000,
                 1,  # num of sessions: 1(fix)
                 0,  # activity_type: general
                 26,  # event: activity