Chris Greenhalgh (cmg@cs.nott.ac.uk) 1

Coursework 2 implementation options

Chris GreenhalghG54UBI / 2011-03-02

Chris Greenhalgh (cmg@cs.nott.ac.uk) 2

Contents

• Target device(s)• Implementation options– Supported: Google AppInventor, HTML/JS,

PhoneGap, Android Java (native) App– Unsupported: Titanium mobile, other native app

• Sensor options• Summary

Chris Greenhalgh (cmg@cs.nott.ac.uk) 3

Target device(s)

• Android is the only supported target platform– Freely available tools– Freely available

emulators

Chris Greenhalgh (cmg@cs.nott.ac.uk) 4

Implementation options…

Supported• Google AppInventor• HTML/JS Browser App• PhoneGap• Android native (java) app

Unsupported• Titanium mobile• Other native app

Chris Greenhalgh (cmg@cs.nott.ac.uk) 5

Option 1: Google AppInventor

• Creates simple Android apps– Drag’n’Drop UI builder– Scratch-like visual

programming

• Web tool plus local tools (JNLP)– Requires Google account

http://appinventor.googlelabs.com/about/

Chris Greenhalgh (cmg@cs.nott.ac.uk) 6

Option 2: HTML/JS Browser App

• Dynamic web pages – HTML layout– CSS styling– JavaScript behaviour

• Compatible with many devices– Limited low-level/sensor

access

• Various tool(s)– E.g. Eclipse

Chris Greenhalgh (cmg@cs.nott.ac.uk) 7

Option 3: PhoneGap

• Converts HTML/JS apps to installable phone apps

• Compatible with many devices– Better low-level/sensor

access– Option for native

extensions

• Requires app build – Eclipse for Android

http://www.phonegap.com/

Chris Greenhalgh (cmg@cs.nott.ac.uk) 8

Option 4: Android Native (Java) App

• Creates Android apps– OO Java framework

specific to Android– Limited DnD UI builder

• Complete access to device APIs, sensors, …

• Requires Eclipse IDE plus Android SDK and Eclipse plugins

• Only suitable for experienced developershttp://developer.android.com/

LIMITED SUPPORT

Chris Greenhalgh (cmg@cs.nott.ac.uk) 9

Other option: Titanium Mobile• Creates mobile apps

– All programming in Javascript– Custom (native) widgets– Converted to installable App

(similar to PhoneGap)

• Compatible with Android and iPhone– Good low-level/sensor access– Option for native extensions

• Simple desktop GUI project management/build tool– plus your own choice of JS

editorhttp://www.appcelerator.com/products/titanium-mobile-application-development/

NOT SUPPORTED

Chris Greenhalgh (cmg@cs.nott.ac.uk) 10

Other option: Other native app

• E.g. iPhone/iOS• Creates app for that

target– Platform-specific

development

• Complete access to device APIs, sensors, …

• Platform-specific tools

NOT SUPPORTED

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Implementation SummaryAppInventor Browser PhoneGap Native Android

Support Yes Yes Yes Limited

Installable / standalone app

Yes No Yes Yes

GUI DnD editor HTML/CSS HTML/CSS Java/XML

Logic Visual programming

Javascript Javascript Java2 (Android framework)

GPS Yes1 Yes Yes Yes

Other sensors Compass, Accelerometer, barcode, photo

- Compass, Accelerometer, barcode, photo

Compass, Accelerometer, barcode, camera, …

Map view Limited2 Yes Yes Yes

Networking Limited HTTP HTTP HTTP, TCP, …

Android Yes Yes Yes Yes

iPhone No Yes Yes (requires Mac OS-X)

No

Easier

Easy transition1 Limited options for region logic2 By switch to map app (no overlay)

Chris Greenhalgh (cmg@cs.nott.ac.uk)

Chris Greenhalgh (cmg@cs.nott.ac.uk) 12

Sensor options

Supported• GPS

– Lat/long– Regions

• Compass• Accelerometer• 2D barcode• Remote sensors

– Environmental

Unsupported• Remote sensors

– Interactive/installation

• Photo• Continuous camera input• Network scanning

– Bluetooth, WiFi

• NFC / RFID

Chris Greenhalgh (cmg@cs.nott.ac.uk) 13

GPS lat/long

• Outdoor position– Requires view of sky

• Typically 5m accuracy• Updates once/second• Takes up to a minute

(sometimes more) to get initial “fix”

Chris Greenhalgh (cmg@cs.nott.ac.uk) 14

A note on network location providers

• iPhone and Android also support location from network information– GSM cell, WiFi networks

• Requires network lookup (online)

• Very rough position– 10s metres (urban) –

1000s metres (rural)

Chris Greenhalgh (cmg@cs.nott.ac.uk) 15

GPS regions

• Classification of GPS position in terms of “meaningful” regions– E.g. “near the statue”

• Depends on GPS fix & accuracy– Classified at run-time

• Requires region geometry to be pre-specified

Chris Greenhalgh (cmg@cs.nott.ac.uk) 16

Compass

• Many phones contain a 1, 2 or 3-D magnet flux compass– Gives approximate

orientation (heading)– Affected by nearby

ferrous objects– Native Android apps may

get pitch and roll as well as heading (azimuth)

Chris Greenhalgh (cmg@cs.nott.ac.uk) 17

Accelerometer

• Monitors 3D acceleration of device– Acceleration = rate of

change of velocity– Gravity = 9.8ms-2 (down)

Chris Greenhalgh (cmg@cs.nott.ac.uk) 18

2D Barcode

• Several standards for encoding data (esp. URLs) as 2D barcodes– E.g. QR Code

• Supported by standard reader apps using camera– E.g. ZXing for Android

• Can be generated and placed to identify – Specific objects– Places– People

http://www.cs.nott.ac.uk/~cmg/

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Remote sensors

• Network access to remote sensors– E.g. Phidget Single Board

Computer w.

• Embedded in environment*– E.g. Temperature,

humidity, light

• Interactive installation– E.g. Touch, distance,

pressure, force, …

IR Distance

IR Reflective

Vibration

Force

Magnetic

Rotation

Touch

Motion (PIR)

Slider

Mini-joystick

pressure

Voltage

current

temperature

Temp & humidity

light

sonar

ID distance

* One set of sensors will be installed at the edge of the CS Atrium for test/development

NOT SUPPORTED

Chris Greenhalgh (cmg@cs.nott.ac.uk) 20

Sensor summaryAppInv PhoneGap Emulator Device(s)

GPS lat/long Yes Yes Yes (no accuracy) Most

GPS region Limited Yes Yes Most (GPS)

Compass Yes Yes No Most

Accelerometer Yes Yes No Many

2D barcode Yes1 Yes1 No2 Most (Camera)

Remote sensors Yes3 Yes3 Yes4 All (network)

1: requires ZXing app2: a work-around might be possible using an alternative app (TBD)3: requires bridging service (for AppInv specifically as WebTinyDB)4: remote sensors are outside the emulator (emulating the remote sensors is another matter)

Chris Greenhalgh (cmg@cs.nott.ac.uk) 21

Conclusion

• First:– Identify the target platform (default Android)– Identify the implementation approach you will use

• Taking account of technical skills/background plus interests and platform capabilities

– Identify the sensor(s) that you will use• Bear in mind emulator support and your options for

access to real device(s)

• Scope/refine your coursework 2 concept accordingly