diff --git a/src/agent_gsm.py b/src/agent_gsm.py
index e200e08..1eb28b0 100644
--- a/src/agent_gsm.py
+++ b/src/agent_gsm.py
@@ -288,11 +288,10 @@ def perform_answerer():
     while True:
         # Remove old recording
         record_file = f'/dev/shm/bt_record.wav'
-
-        cmd = f'/usr/bin/python3 {DIR_THIS}/bt_call_controller.py --play-file {REFERENCE_AUDIO} --record-file {record_file} --timelimit {int(reference_length)}'
-        retcode = os.system(cmd)
-        if retcode != 0:
-            utils.log(f'Got non-zero exit code {retcode} from BT call controller, exiting.')
+        try:
+            bt_call_controller.run(play_file=REFERENCE_AUDIO, record_file=record_file, timelimit_seconds=int(reference_length), target=None)
+        except Exception as e:
+            utils.log(f'BT I/O failed, exiting. Error: {str(e)}')
             break
 
         # Call analyzer script
diff --git a/src/bt_call_controller.py b/src/bt_call_controller.py
index 8001203..551e2d4 100644
--- a/src/bt_call_controller.py
+++ b/src/bt_call_controller.py
@@ -231,26 +231,23 @@ def get_pid(name):
     return int(subprocess(["pidof","-s",name]))
 
 
-def main(args: dict):
+def run(play_file: str, record_file: str, timelimit_seconds: int, target: str):
     global CALL_PATH, CALL_LOCK, CALL_ADDED, CALL_REMOVED
 
     # Ensure Ctrl-C handler is default
     # signal.signal(signal.SIGINT, signal.SIG_DFL)
    
     # Check if input file exists
-    if not os.path.exists(args['play_file']):
+    if not os.path.exists(play_file):
         utils.log(f'Problem: file to play ({args["play_file"]}) doesn\'t exists.')
         exit(os.EX_DATAERR)
 
 
-    # Duration in seconds
-    watchdog_timeout = int(args['timelimit'])
-
-    if watchdog_timeout == 0:
+    if timelimit_seconds == 0:
         # Use duration of played file
-        audio_file = soundfile.SoundFile(args['play_file'])
-        watchdog_timeout = int(audio_file.frames / audio_file.samplerate + 0.5)
-        utils.log(f'Play timeout is set to {watchdog_timeout} seconds')
+        audio_file = soundfile.SoundFile(play_file)
+        timelimit_seconds = int(audio_file.frames / audio_file.samplerate + 0.5)
+        utils.log(f'Play timeout is set to {timelimit_seconds} seconds')
     
     # Empty call path means 'no call started'
     # CALL_LOCK.acquire()
@@ -269,15 +266,11 @@ def main(args: dict):
     PHONE.setup_dbus_loop()
 
     # Start call
-    if 'target' in args:
-        target_number = args['target']
-        if target_number is not None and len(target_number) > 0:
-            # Make a call
-            dial_number(target_number, args['play_file'])
-        else:
-            answer_call(args['play_file'])
+    if target is not None and len(target) > 0:
+        # Make a call
+        dial_number(target, play_file)
     else:
-        answer_call(args['play_file'])
+        answer_call(play_file)
 
     # Don't make volume 100% - that's too much
     audio_volume = 50
@@ -286,14 +279,14 @@ def main(args: dict):
     set_headset_mic_volume(audio_volume)
 
     # Start recording
-    utils.log(f'Start recording with ALSA to {args["record_file"]}')
-    process_recording = capture_phone_alsaoutput(args['record_file'])
+    utils.log(f'Start recording with ALSA to {record_file}')
+    process_recording = capture_phone_alsaoutput(record_file)
     utils.log(f'Main loop PID: {os.getpid()}, TID: {threading.get_ident()}')
     
     # Wait until call is finished
     time_start = time.time()
     
-    while not CALL_REMOVED.value and time_start + watchdog_timeout > time.time():
+    while not CALL_REMOVED.value and time_start + timelimit_seconds > time.time():
         time.sleep(0.5)
     
     utils.log(f'Call {CALL_PATH} finished.')
@@ -319,7 +312,7 @@ if __name__ == "__main__":
     
     retcode = 0
     try:
-        main(args)
+        run(args['play_file'], args['record_file'], args['timelimit'], args['target'] if 'target' in args else None)
     except KeyboardInterrupt as e:
         print('Ctrl-C pressed, exiting')
         cleanup()