Loosely-coupled Component Infrastructure
Using LooCI Contiki / OSGi / Android
1
Structure
Programming
LooCI OSGi
LooCI Contiki
Setup of environment
Assignment
2
To start
Copy the virtual machine from USB stick on your drive
Get, install & open virtual box or vm software
Download
Ask for the USB stick containing executables
Import the loociVM into your virtual machine :
file -> import appliance -> select appliance -> select the copy
-> next -> next.
Password of VM is ‘user’
3
To Start
Make sure that the VM network is set to “bridged adaptor”
Settings -> network
Or ctrl+s while in VM -> network -> adaptor1
Or devices -> network adaptors
To change keyboard if required:
1) Click on the icon placed at the top right corner.
2) Click on System Settings
3) Click on Keyboard icon
4) Click on Layout Setting label.
5) Add your language in the layout tab and put it as the first one in the
list.
4
LooCI OSGi
Component = OSGi bundle
loociOsgi workspace : home/user/looci/looci.osgi
To create a new component:
Create new plug-in project
Add LooCI services as dependency & required bundle in metaInf
Activator must extend the LoociComponent class
• At meta-inf set activator to your component class
To create jar:
Copy a build.xml file from another component (several present in osgi)
Adjust name of project
Do ant build in eclipse
file “projectName.jar” in felix/looci/comps -> local component repository
Deploy : in gui : “deploy projectName.jar nodeIP osgi”
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OSGi : Declaring codebase
public class LoociSensor extends LoociCodebase {
public LoociSensor () {
super("Sensordisplay",
new short[] {EventTypes.TEMP_READING},
new short[] {});
}
@Override
public ILoociInstance createLoociComponent() {
return new LoociSensorInstance();
}
// component name
//provided temp
//nothing required
//abstract factory pattern
}
6
OSGi : Declaring component
public class LoociSensorComponent extends LoociComponent
implements ITimeListener {
private LoociTimer timer;
public void componentStart() {
timer = new LoociTimer(this, 20, true);
rand = new Random();
timer.start();
}
public void componentStop() {
timer.stop();
}
7
OSGi: Declaring component:
Sending events
@Override
public void receive(short eventID, byte[] payload) {
// do nothing, this is event producer
}
@Override
public void doOnTimeEvent(LoociTimer expiredTimer) {
//callback for timer interface
byte val = (byte)rand.nextInt();
//random value
publish(EventTypes.TEMP_READING, new byte[]{val});
}
}
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OSGi: Declaring component
Receiving event & print it out
@Override
public void receive(short eventID, byte[] payload) {
if(eventID == EventTypes.TEMP_READING){
System.out.println(“received temp: “+ payload[0]);
}
}
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LooCI Contiki
Create folder in component directory
Copy / create makefile
Easiest => copy from existing project and rename projectname in make file
and c and header file (copy a-testcomponent folder)
Make sure link to looci is correct, can change due to path
To declare component: C Macros
To create a component:
Go to the contiki component folder
• /home/user/looci/looci.contiki/looci/applications/
Enter : ‘make copy’
• Potentially requires root in some cases, pw = user
• Automatically puts file in component repository (if makefile.component set)
To deploy: use gui and name the component file
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Contiki: Sending/ receiving
#define INT_TEMP_EVENT 402
#define PROPERTY_ID_INTERVAL 1
struct state{struct etimer et;uint8_t interval;};
static struct state initVar PROGMEM = {.interval = 10};
#define LOOCI_COMPONENT_NAME temp_sample
#define LOOCI_NR_PROPERTIES 1
LOOCI_PROPERTIES({PROP_TIME_INTERVAL,DATATYPE_BYTE,offsetof(struct state,interval),1,name});
COMPONENT_INTERFACES(INT_TEMP_EVENT );
COMPONENT_NO_RECEPTACLES();
LOOCI_COMPONENT_INIT("Temp Sampling",struct state,&initVar);
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Contiki: Sending/ receiving
static uint8_t activate(struct state* compState, void* data){
ETIMER_SET(&compState->et, compState->interval * CLOCK_SECOND);
return LC_SUCCESS;
}
static uint8_t time(struct state* compState, void* data){
uint8_t temp = rng();
PUBLISH_EVENT(TEMP_EVENT, (uint8_t*)&temp, sizeof(temp));
ETIMER_RESET(&compState->et);
return LC_SUCCESS;
}
COMP_FUNCS_INIT //THIS LINE MUST BE PRESENT
COMP_FUNC_ACTIVATE(activate)
COMP_FUNC_TIMER(time)
COMP_FUNCS_END(NULL)//THIS LINE MUST BE PRESENT
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LooCI Gui overview
Gui
Simple Gui to manage LooCI platforms
Enter commands, receive feedback
List of commands : enter “help”
More info on command enter “help commandName”
For more information : slides in the back
No access control in these VM’s
Please be careful not to mess up other people’s configurations
When working with android device, only do wires, or ask for us !!
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Exercises:
Exercise 1: receive temp, filter, forward, press button, do buzz
Deploy the necessary components
Instantiate & wire all components
Activate components -> should produce beep
Exercise 2:
Write a forward temperature on button press component
Deploy & wire instead of the previous components
Result should be the same
Exercise 3:
Write a button press component for OSGi
On button press on your local machine / android device -> avr buzzes
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Exercise 1: Setup to realize
OSGi NODE: aaab::XY
NODE: nodeXY
Buzzer
ButtonSensor
TempFilter
Buzz_ev
Ev = 403
Tutorial
Back-end
Btn_ev
Ev = 401
Temp_ev
Ev = 402
XY = pcNr
01, 02, 03,
10, 11, etc
Sensor node
TempSensor
Gateway
Temp_ev
Ev = 402
nodeBC
Aaaa::1
Aaab::1
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Overview of addresses and ID’s
Your backend IP: aaab::XY (e.g. aaab::2 / aaab::12)
Your back-end component: codebase ID = 10, component ID = 10
tutorialButtonComp:
codebase ID = 11, component ID = 11
Your node IP: nodeXY (e.g. node2 / node12)
Temp filter :
Button sensor:
Buzzer :
ButtonTempCounter:
codebase ID = 2, component ID = 10
codebase ID = 3, component ID = 11
codebase ID = 4, component ID = 12
codebase ID = 5, component ID = 13
Temp producer : nodeBC
Temp producer component: codebase ID = 2, component ID = 10
• Please do not touch this node
Please: only use your own nodes
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Start environment
Import VM, set network settings to bridged adaptor
Start VM
Each of you must receive a unique numbered node: nr is XY
Initiate your IP address with the correct number
Double click the setup icon
The user password is asked
• Enter ‘user’
Your number is asked
• Enter your own number
• (Will keep asking for number until valid number is entered)
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Start LooCI
Start LooCI gui
Double click on loociGui icon on desktop
Open eclipse environments (icon on desktop) :
/home/user/looci/looci.contiki workspace should be selected
Alternatively you can work in command line and use text editor
/home/user/looci/looci.contiki/looci/applications/tutorialComponents/
/home/user/looci/looci.osgi/LoociComponents/
You now have a working environment and should be able to ping the
nodes:
In gui enter ‘ping nodeXY’ with XY your number
» Enter ‘help’ for list of commands
» Enter ‘ls’ to see list of available components
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At end
Please click the end icon when you finish
This sends the log file containing the trace of your gui
This allows us to view where common mistakes were made
No personal info is in these files
We identify by node number
Feel free to check 
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1a Deploy the back-end
After starting LooCI OSGi, the LooCI gui should appear
Deploy and activate your backend component
“deploy tutorialBackend.jar aaab::XY osgi”
• Deploys your backend component
• Should return codebaseID 10
“instantiate 10 aaab::XY”
• Creates component instance of backend
– a window should appear on your screen
• Should return componentID 10
“activate 10 aaab::XY”
• Activates your backend
XY is the number of the node you are assigned
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1b Instantiate and wire
Now, instantiate all the components on your node
We already deployed the necessary components to your node
Afterwards you will deploy your own component
‘instantiate 2 nodeXY’ -> returns componentID 10
This instantiates the temp filter
‘instantiate 3 nodeXY’ -> returns componentID 11
This instantiates the button sensor
‘instantiate 4 nodeXY’ -> returns componentID 12
This instantiates the buzzer component
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1b Perform wirings on node
‘wireFrom temp_ev 0 nodeBC 10 nodeXY’
Send temp events from sensor node broadcaster to filter
‘wireTo temp_ev 10 nodeXY aaab::XY’
Send temp events from filter to your backend
‘wireTo button_ev 11 nodeXY aaab::XY’
Send button press events from your node to your backend
‘wireFrom buzz_ev 0 :: 12 nodeXY’
Deliver buzz events from any address to component 12 on your node
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1b Perform wirings backend
‘wireFrom temp_ev 0 nodeXY 10 aaab::XY’
Deliver temp events from your node to component 10
‘wireFrom button_ev 0 nodeXY 10 aaab::XY’
Deliver button events from your node to component 10
‘wireTo buzz_ev 10 aaab::XY nodeXY’
Send buzz events from your backend to your node
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1c Activate components
‘activate 10 nodeXY’
Activates the temp filter
‘activate 11 nodeXY’
Activates the button sensor
‘activate 12 nodeXY’
Activates the buzzer
=> press button on avr, you should see on your OSGi interface that
an event comes in, and that it sends out a new buzz event.
If it does not work : check wires & state of all components
Do ‘getState 10 nodeXY’ to see if component 10 is active (returns 1)
To view the setup, enter ‘draw nodeXY’ in the gui
This shows the current wirings on your avr raven node
» NOTE: visualizer is still in beta, so might not be perfect 
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Exercise 1: Setup realized
OSGi NODE: aaab::XY
NODE: nodeXY
Buzzer
Buzz_ev
Ev = 403
Tutorial
Back-end
Btn_ev
Ev = 401
ButtonSensor
TempFilter
Temp_ev
Ev = 402
XY = pcNr
01, 02, 03,
10, 11, etc
Sensor node
TempSensor
Gateway
Temp_ev
Ev = 402
nodeBC
Aaaa::1
Aaab::1
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1d Play around
Change the wires and the properties a bit, see how it affects your
composition.
For example: set temp filter property
Get lower bound of temp filter
• getProperty 1 10 node1 byte
– Should return 0
Set property to 100 => should not allow any more events
• setProperty 1 10 node1 100 byte
Please be careful and do not interrupt the nodes of others
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1e Deactivate
Deactivate temp filter
‘deactivate 10 nodeXY ‘
• deactivate temp filter
‘deactivate 12 nodeXY ‘
• Deactivate buzzer
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Setup to realize exercise 2
OSGi NODE: aaab::XY
NODE: nodeXY
Buzzer
ButtonSensor
ButtonTemp
Counter
Buzz_ev
Ev = 403
Tutorial
Back-end
Btn_ev
Ev = 401
Temp_ev
Ev = 402
XY = pcNr
01, 02, 03,
10, 11, etc
Sensor node
TempSensor
Gateway
Temp_ev
Ev = 402
nodeBC
Aaaa::1
Aaab::1
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Exercise 2
Create a buttonTempCounter
Create a component that allows a temperature event to pass for
each time you press the button
Go to your Contiki eclipse environment (or other editor)
Looci contiki path/workspace : /home/user/looci/looci.contiki/looci
Component subfolder : applications/tutorialComponents/buttonTempCounter
Go to: applications/tutorialComponents/buttonTempCounter/
Open buttonTempCounter.c
Write the necessary code to do the following:
If the button is pressed, you increment the nrToSend
If the temp reading comes in, and nrToSend > 0, then publish the temp
reading again, and decremetn nrReads
Note, the nrReads is already a property in the example
You can check the tempSample and buttonSensor projects for aid
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2b Build and copy
Once you made your component you can build it
Open a linux terminal and go to
/looci/looci.contiki/looci/applications/tutorialComponents/buttonTempCounter
Enter “sudo make copy” -> this creates the component file if all goes
well
The component is copied in the looci component repository
Do “ls” in LooCI Gui
• This should show that you now have a new component there
Now you have put the component in the LooCI component
repository, from which you can easily deploy it
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2c Deploy and wire
Go back to your gui, and deploy and wire the component
‘ deploy buttonTempCounter.comp nodeXY raven ‘
• Returns codebaseID 5
‘instantiate 5 nodeXY ‘
• Returns componentID 13
‘ wireFrom temp_ev 0 nodeBC 13 nodeXY ‘
‘ wireLocal button_ev 11 13 nodeXY ‘
‘ wireTo temp_ev 13 nodeXY aaab::XY ‘
‘ activate 13 nodeXY ‘
Component is now activated and should be running
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2d Using properties
Press the button a few times
Do ‘getProperty 1 13 nodeXY byte’
• This returns the number of reads the component still has to do
• Wait a bit, do it again, see it decrease
Do ‘setProperty 1 13 nodeXY 5 byte’
• Now you tell the component to let 5 readings through
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Setup realized exercise 2
OSGi NODE:
aaab::XY
NODE: nodeXY
Buzzer
ButtonSensor
ButtonTemp
Counter
Buzz_ev
Ev = 403
Tutorial
Back-end
Btn_ev
Ev = 401
Temp_ev
Ev = 402
XY = pcNr
01, 02, 03,
10, 11, etc
Sensor node
TempSensor
Gateway
Temp_ev
Ev = 402
nodeBC
Aaaa::1
Aaab::1
33
Exercise 2: Learned lessons
This exercise showed the following
The deployment interface between osgi and raven is identical
Changing internal configuration on raven did not affect the backend
• Easy adaptation of internal configuration
Changing component state very straight forward
Creating and integrating new components in the event flow
Property and events work seamless
You can do ‘draw nodeXY’
Shows you the new component composition
• Remember, visualizer is still in beta
34
Exercise 3: Make buzzer go off
You will create an OSGi component, that sends out a button event.
In the first instance, this button event will be wired to the back-end
component, which will then send out a buzz event
Switch eclipse to osgi workspace
Go to OSGi workspace: project comp_tutorialButtonSender.
Open the buttonSenderComponent
File -> switch workspace -> /home/user/looci/looci.osgi
Or location:
/home/user/looci/looci.osgi/LoociComponent/ButtonSender
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Setup to realize exercise 3
OSGi NODE: aaab::XY
NODE: nodeXY
Buzzer
ButtonSensor
ButtonTemp
Counter
Buzz_ev
Ev = 403
Tutorial
Back-end
Btn_ev
Ev = 401
Btn_ev
Ev = 401
Temp_ev
Ev = 402
ButtonSend
Component
Sensor node
TempSensor
Gateway
Temp_ev
Ev = 402
nodeBC
Aaaa::1
Aaab::1
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3b Implement in OSGi
What you must do is make it publish a buttonEvent
Implement the relevant method.
In the folder is an ant build file. Execute the build file
Right click on build.xml,
Or do ‘ant’ in the right folder in terminal
This automatically puts the component jar in the component folder.
Deploy, and wire the button press component to your back-end
server
This is a wireLocal command !!
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3c Deploy and wire
Commands:
‘deploy tutorialButtonSender.jar aaab::XY osgi’ -> codebaseId 11
‘instantiate 11 aaab::XY’ -> componentID 11
‘wireLocal button_ev 11 10 aaab::XY’
‘activate 11 aaab::XY’
Activate the buzzer again to hear buzzes:
‘activate 12 nodeXY’
Now if you press the button on your gui, the buzzer goes
Deactivate buzzer again 
‘deactivate 12 nodeXY’
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Exercise 4 : Do a temp reading
on button press in gui
Concept, we only take a temp reading if we press a button
Send the button press event from back-end to node
wireTo button_ev 11 aaab::XY nodeXY
Deliver button press event from back_end to component on node
wireFrom button_ev 0 aaab::XY 13 nodeXY
Extra:
Wire the tempFilter component on Contiki between the
buttonTempSender and the buttonTempCounter component
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Setup to realize exercise 4
OSGi NODE:
aaab::XY
NODE: nodeXY
Buzzer
ButtonSensor
ButtonTemp
Counter
Buzz_ev
Ev = 403
Tutorial
Back-end
Btn_ev
Ev = 401
Btn_ev
Ev = 401
Temp_ev
Ev = 402
ButtonSend
Component
Btn_ev
Ev = 401
Sensor node
TempSensor
Gateway
Temp_ev
Ev = 402
nodeBC
Aaaa::1
Aaab::1
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Exercise 5: Write a temp filter
You have seen how to write new components in contiki and osgi
Now write an osgi component almost from scratch
It must filter temp events before being shown on the screen
It receives temp events, checks whether they’re inside the
boundaries and publishes them.
To start: Open the Comp_TutorialFilter project
Declare provided and required interfaces in LoociFilter.java
Create necessary properties
Write filter logic in the receive method, and publish the event if it
matches
Execute the ant build in eclipse
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Setup to realize exercise 5
OSGi NODE: aaab::XY
NODE: nodeXY
Buzzer
ButtonSensor
ButtonTemp
Counter
Buzz_ev
Ev = 403
Tutorial
Back-end
Btn_ev
Ev = 401
Temp
Filter
Temp_ev
Ev = 402
Btn_ev
Ev = 401
ButtonSend
Component
Btn_ev
Ev = 401
Sensor node
TempSensor
Gateway
Temp_ev
Ev = 402
nodeBC
Aaaa::1
Aaab::1
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5b Deploy and wire filter
Insert the tempfilter between the back-end component and the
remote node
Remove existing wire from remote node to back-end component at
back-end (unwireFrom)
Wire your buttonTempCounter remote component to the filter
(wireFrom)
Wire the filter component to the back-end component (wireLocal)
Don’t forget to activate the components
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Exercise 6 : Use adroid as
button and to log
Concept: add a wireless android device to the setup
!!Ask for the android IP address and component to use !!
Connect your unique component on the android device to your
node.
If button is pressed, a temperature reading is taken
You can also send out the button to your back-end => buzzer
Wire the temperature also to the correct OSGi component on
android
Be carefull, android is a shared resource
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Lessons Learned
Homogeneous interface for heterogeneous devices
Software development in two languages, yet they interact the same
Distributed event bus
Changes on one node do not necessarily influence changes on another
Clashes are possible though !!
Properties and events work seamless together
Limited overhead to create new behaviour
45
Questions?
For any other questions with regards to LooCI:
Architecture/collaborations : danny.hughes@cs.kuleuven.be
Contiki/Osgi : jef.maerien@cs.kuleuven.be
SunSPOT : klaas.thoelen@cs.kuleuven.be
Android : rafael.bachiller@cs.kuleuven.be
46
Relevant commands
Command Arguments: (also available in gui by entering ‘help’)
deploy
file - address - nodetype
removeCodebase
codebase id - address
Instantiate
codebase id - address
destroyComponent
component id - address
Activate
component id - address
deactivate
component id - address
wireLocal
event id - src component id - dst component id - address
unwireLocal
event id - src component id - dst component id - address
wireFrom
event id - src comp id - src address - dst comp id - dst addr
unwireFrom
event id - src comp id - src addr - dst comp id - dst addr
wireTo
event id - src component id - dst address - src address
unwireTo
event id - src component id - dst address - src address
resetWires
component id - address
setProperty
property id - comp id - addr - prop value - prop type
47
Relevant commands (2)
getComponentsOfCodebase codebase id - address
getCodebaseName
codebase id - address
getCodebaseIDOfComponent component id - address
getCodebaseNameOfComponent component id - address
getComponentIDs
address
getState
component id - address
getProvidedInterfaces
component id - address
getRequiredInterfaces
component id - address
getLocalWires
event id - src component id - dst component id - address
getWiresTo
event id - src component id - dst address - address
getWiresFrom
event id - src comp id - src addr - dst comp id - dst addr
getProperties
component id - address
getProperty
property id - component id - address - property type
getPropertyInfo
property id - component id - address
getPlatformType
address
48
Relevant node addressing
NodeBC -> broadcast node
Aaab::xy -> your own back-end
nodeXY -> node as defined in hosts file
Please make sure you only user your own nodes
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Relevant event types
button_ev
temp_ev
buzz_ev
401
402
403
Relevant properties:
We only used propertyId 1 to make it easy for everyone
For filtering we propose to use propertyId 1 for the lower boundary
and 2 for the upper boundary
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