I have added two lines to the binary_sensor/xiaomi.py:
from datetime import timedelta
SCAN_INTERVAL = timedelta(seconds=5)
The scan interval is 5 seconds now. A quick test revealed the 60 seconds resolution of the sensor:
2017-08-05 10:53:20 DEBUG (Thread-5) [homeassistant.components.xiaomi] PUSH >> <Entity Motion Sensor_158d000113e31f: off>: {'status': 'motion'}
2017-08-05 10:53:21 DEBUG (Thread-7) [homeassistant.components.binary_sensor.xiaomi] Updating xiaomi sensor 158d000113e31f by polling. Current state is True
2017-08-05 10:53:21 DEBUG (Thread-7) [homeassistant.components.xiaomi] PUSH >> <Entity Motion Sensor_158d000113e31f: on>: {'status': 'motion', 'voltage': 3075}
2017-08-05 10:53:28 DEBUG (Thread-8) [homeassistant.components.binary_sensor.xiaomi] Updating xiaomi sensor 158d000113e31f by polling. Current state is True
2017-08-05 10:53:28 DEBUG (Thread-8) [homeassistant.components.xiaomi] PUSH >> <Entity Motion Sensor_158d000113e31f: on>: {'status': 'motion', 'voltage': 3075}
2017-08-05 10:53:33 DEBUG (Thread-8) [homeassistant.components.binary_sensor.xiaomi] Updating xiaomi sensor 158d000113e31f by polling. Current state is True
2017-08-05 10:53:33 DEBUG (Thread-8) [homeassistant.components.xiaomi] PUSH >> <Entity Motion Sensor_158d000113e31f: on>: {'status': 'motion', 'voltage': 3075}
2017-08-05 10:53:39 DEBUG (Thread-3) [homeassistant.components.binary_sensor.xiaomi] Updating xiaomi sensor 158d000113e31f by polling. Current state is True
2017-08-05 10:53:39 DEBUG (Thread-3) [homeassistant.components.xiaomi] PUSH >> <Entity Motion Sensor_158d000113e31f: on>: {'status': 'motion', 'voltage': 3075}
2017-08-05 10:53:46 DEBUG (Thread-3) [homeassistant.components.binary_sensor.xiaomi] Updating xiaomi sensor 158d000113e31f by polling. Current state is True
2017-08-05 10:53:46 DEBUG (Thread-3) [homeassistant.components.xiaomi] PUSH >> <Entity Motion Sensor_158d000113e31f: on>: {'status': 'motion', 'voltage': 3075}
2017-08-05 10:53:51 DEBUG (Thread-9) [homeassistant.components.binary_sensor.xiaomi] Updating xiaomi sensor 158d000113e31f by polling. Current state is True
2017-08-05 10:53:51 DEBUG (Thread-9) [homeassistant.components.xiaomi] PUSH >> <Entity Motion Sensor_158d000113e31f: on>: {'status': 'motion', 'voltage': 3075}
2017-08-05 10:53:57 DEBUG (Thread-9) [homeassistant.components.binary_sensor.xiaomi] Updating xiaomi sensor 158d000113e31f by polling. Current state is True
2017-08-05 10:53:57 DEBUG (Thread-9) [homeassistant.components.xiaomi] PUSH >> <Entity Motion Sensor_158d000113e31f: on>: {'status': 'motion', 'voltage': 3075}
2017-08-05 10:54:03 DEBUG (Thread-7) [homeassistant.components.binary_sensor.xiaomi] Updating xiaomi sensor 158d000113e31f by polling. Current state is True
2017-08-05 10:54:03 DEBUG (Thread-7) [homeassistant.components.xiaomi] PUSH >> <Entity Motion Sensor_158d000113e31f: on>: {'status': 'motion', 'voltage': 3075}
2017-08-05 10:54:10 DEBUG (Thread-6) [homeassistant.components.binary_sensor.xiaomi] Updating xiaomi sensor 158d000113e31f by polling. Current state is True
2017-08-05 10:54:10 DEBUG (Thread-6) [homeassistant.components.xiaomi] PUSH >> <Entity Motion Sensor_158d000113e31f: on>: {'status': 'motion', 'voltage': 3075}
2017-08-05 10:54:15 DEBUG (Thread-6) [homeassistant.components.binary_sensor.xiaomi] Updating xiaomi sensor 158d000113e31f by polling. Current state is True
2017-08-05 10:54:15 DEBUG (Thread-6) [homeassistant.components.xiaomi] PUSH >> <Entity Motion Sensor_158d000113e31f: on>: {'status': 'motion', 'voltage': 3075}
2017-08-05 10:54:20 DEBUG (Thread-11) [homeassistant.components.binary_sensor.xiaomi] Updating xiaomi sensor 158d000113e31f by polling. Current state is True
2017-08-05 10:54:20 DEBUG (Thread-11) [homeassistant.components.xiaomi] PUSH >> <Entity Motion Sensor_158d000113e31f: on>: {'status': 'motion', 'voltage': 3075}
2017-08-05 10:54:26 DEBUG (Thread-2) [homeassistant.components.binary_sensor.xiaomi] Updating xiaomi sensor 158d000113e31f by polling. Current state is True
2017-08-05 10:54:26 DEBUG (Thread-2) [homeassistant.components.xiaomi] PUSH >> <Entity Motion Sensor_158d000113e31f: on>: {'status': 'no_motion', 'voltage': 3075}
--> 1m 6s
2017-08-05 10:54:34 DEBUG (Thread-4) [homeassistant.components.xiaomi] PUSH >> <Entity Motion Sensor_158d000113e31f: off>: {'status': 'motion'}
2017-08-05 10:54:38 DEBUG (Thread-4) [homeassistant.components.binary_sensor.xiaomi] Updating xiaomi sensor 158d000113e31f by polling. Current state is True
2017-08-05 10:54:38 DEBUG (Thread-4) [homeassistant.components.xiaomi] PUSH >> <Entity Motion Sensor_158d000113e31f: on>: {'status': 'motion', 'voltage': 3075}
2017-08-05 10:54:44 DEBUG (Thread-4) [homeassistant.components.binary_sensor.xiaomi] Updating xiaomi sensor 158d000113e31f by polling. Current state is True
2017-08-05 10:54:44 DEBUG (Thread-4) [homeassistant.components.xiaomi] PUSH >> <Entity Motion Sensor_158d000113e31f: on>: {'status': 'motion', 'voltage': 3075}
2017-08-05 10:54:49 DEBUG (Thread-12) [homeassistant.components.binary_sensor.xiaomi] Updating xiaomi sensor 158d000113e31f by polling. Current state is True
2017-08-05 10:54:49 DEBUG (Thread-12) [homeassistant.components.xiaomi] PUSH >> <Entity Motion Sensor_158d000113e31f: on>: {'status': 'motion', 'voltage': 3075}
2017-08-05 10:54:56 DEBUG (Thread-12) [homeassistant.components.binary_sensor.xiaomi] Updating xiaomi sensor 158d000113e31f by polling. Current state is True
2017-08-05 10:54:56 DEBUG (Thread-12) [homeassistant.components.xiaomi] PUSH >> <Entity Motion Sensor_158d000113e31f: on>: {'status': 'motion', 'voltage': 3075}
2017-08-05 10:55:01 DEBUG (Thread-11) [homeassistant.components.binary_sensor.xiaomi] Updating xiaomi sensor 158d000113e31f by polling. Current state is True
2017-08-05 10:55:01 DEBUG (Thread-11) [homeassistant.components.xiaomi] PUSH >> <Entity Motion Sensor_158d000113e31f: on>: {'status': 'motion', 'voltage': 3075}
2017-08-05 10:55:07 DEBUG (Thread-8) [homeassistant.components.binary_sensor.xiaomi] Updating xiaomi sensor 158d000113e31f by polling. Current state is True
2017-08-05 10:55:07 DEBUG (Thread-8) [homeassistant.components.xiaomi] PUSH >> <Entity Motion Sensor_158d000113e31f: on>: {'status': 'motion', 'voltage': 3075}
2017-08-05 10:55:13 DEBUG (Thread-12) [homeassistant.components.binary_sensor.xiaomi] Updating xiaomi sensor 158d000113e31f by polling. Current state is True
2017-08-05 10:55:13 DEBUG (Thread-12) [homeassistant.components.xiaomi] PUSH >> <Entity Motion Sensor_158d000113e31f: on>: {'status': 'motion', 'voltage': 3075}
2017-08-05 10:55:19 DEBUG (Thread-5) [homeassistant.components.binary_sensor.xiaomi] Updating xiaomi sensor 158d000113e31f by polling. Current state is True
2017-08-05 10:55:19 DEBUG (Thread-5) [homeassistant.components.xiaomi] PUSH >> <Entity Motion Sensor_158d000113e31f: on>: {'status': 'motion', 'voltage': 3075}
2017-08-05 10:55:25 DEBUG (Thread-11) [homeassistant.components.binary_sensor.xiaomi] Updating xiaomi sensor 158d000113e31f by polling. Current state is True
2017-08-05 10:55:25 DEBUG (Thread-11) [homeassistant.components.xiaomi] PUSH >> <Entity Motion Sensor_158d000113e31f: on>: {'status': 'motion', 'voltage': 3075}
2017-08-05 10:55:31 DEBUG (Thread-11) [homeassistant.components.binary_sensor.xiaomi] Updating xiaomi sensor 158d000113e31f by polling. Current state is True
2017-08-05 10:55:31 DEBUG (Thread-11) [homeassistant.components.xiaomi] PUSH >> <Entity Motion Sensor_158d000113e31f: on>: {'status': 'motion', 'voltage': 3075}
2017-08-05 10:55:37 DEBUG (Thread-6) [homeassistant.components.binary_sensor.xiaomi] Updating xiaomi sensor 158d000113e31f by polling. Current state is True
2017-08-05 10:55:37 DEBUG (Thread-6) [homeassistant.components.xiaomi] PUSH >> <Entity Motion Sensor_158d000113e31f: on>: {'status': 'no_motion', 'voltage': 3075}
2017-08-05 10:56:33 DEBUG (Thread-6) [homeassistant.components.xiaomi] PUSH >> <Entity Motion Sensor_158d000113e31f: off>: {'no_motion': '120'}
--> ~2m
The second shot is strange. I triggered the sensor by waving at the floor for a second both times. It should have result in a one minute period of “motion” too.
Conclusion: The scan interval could be reduced but there is not much room for improvement. Any suggestions?