Android - Sensor Manager

1. Android –
Sensor Manager
Yong Heui Cho @ Mokwon University
Some of slides are referred to:
[1] Nitin Ramchandani, Android OS, slideshare.

2. 2
Smart Device M2M
10. Arduino+Android -
BT+IoTN
11. Arduino - Pressure Sensor
12. Android – Sensor Message
13. BT+IoTN Project - Concept

3. 3
Application
Application Structure
Activity
Context
OS
Resources
Service
lifecycle

4. 4
Activity Lifecycle

5. 5
Lifecycle Comparison
Run Terminate
onCreate() onDestroy()
onStart() onStop()
onResume() onPause()
onRestart() -
onRestoreInstanceState() onSaveInstanceState()

6. 6
Summary of Lifecycle

7. 7
Android vs. Windows
type Android Windows
CPU optimal fast
battery small power supply
memory
mobile DRAM
small
DRAM
large
message handler
message (Message)
or action (String)
message (int)
termination app lifecycle permanent
function call call & proceed
call & wait
or call & proceed

8. 8
MVC Components

9. 9
Android Msg Handler
• Message: containing a description and arbitrary
data object
• Runnable: a command that can be executed
• Handler: allows you to send and process Message
and Runnable
• Looper: used to run a message loop for a thread

10. 10
Concept of Multithread

11. 11
Android Rules
• Do not block the UI thread (or main
thread).
• Do not access the Android UI toolkit
from outside the UI thread.

12. 12
Event Listener
• Interface to process specific events

13. 13
PhoneStateListner
• Monitors changes in specific telephony
states on the device, including service state,
signal strength, message waiting indicator
(voicemail).
Activity
Context
PhoneStateListener
OS
TelephonyManager
listen()

14. 14
Broadcast Receiver
• An Intent-based publish-
subscribe mechanism.
• Great for listening system
events such as SMS messages.
□ Courtesy to Everything of Android, slideshare.

15. 15
BR vs. Listener
type BroadcastReceiver Listener
goal class for Intents
class or interface
for Intents &
others
message
mostly global
messages
mostly specific
messages
period
discontinuous
reception
frequent (or
continuous) reception
construction
static (manifest) or
dynamic
dynamic only

16. 16
Android & Sensors

17. 17
Sensor Manager
• SensorManager
Context.getSystemService(SENSOR_SERVICE
)
• Sensor
SensorManager.getDefaultSensor(Sensor.TYPE
_XXX)
• SensorManager.registerListener(SEL, Sensor, int
samplingPeriodUs)
• SensorManager.unregisterListener(SEL)

18. 18
SensorEventListener

19. 19
Type of Sensors