Embedded Systems

Introduction: -

• computation is integrated with the control and is embedded into the physical system
• Wiring is expensive- so wireless communication between the nodes to become inevitable requirement. so wireless sensor network emerged.
• thesis Networks Consists of individual nodes That are able to interact with Their environment by sensing or controlling physical parameters, hypothesis nodes have to collaborate to Fulfill Their tasks as Ready for a single node is incapable of doing so, and They use wireless communication to enable this collaboration ,

Application examples: -

• Disaster relief Application: - wildfire detection.
• Environment Control and Biodiversity Mapping: - surveillance of the marine ground helps to find the need of offshore wind farms.
• Intelligent buildings: - Building waste vast energy by humidity ventilation and air-conditioning.
• Facility management: - Keyless entry point application where people wear badges did allow a wireless sensor network to check Which person is allowed to enter.
• Machine surveillance and preventive maintenance: - fix sensor nodes to difficult to reach area (main advantage cable free operation).
• Precision Agriculture: - Allows precise agriculture by precise irrigation and fertilizing by placing humidity or soil composition sensor.
• Medicine and healthcare: - postoperative and intensive care; Directly sensor are attached to patients; Doctor patient tracking system.
• Logistics: - embedded in the streets or roadsides can gather information about traffic

Types of application: - 

• Sources of data: - the actual nodes did sense data.
• Sinks: - nodes where the data Should be delivered to 
• Interaction pattern: - between sources and sinks show some typical patterns. Some are as follows: -1. Event Detection report once theyhave detected the occurrence of the specified event; - Event classification-> Numerous event OCCURS. 2.Periodic measurements- Periodically reporting Measured values ​​and triggered by a detected event. 3. Function approximation and Edge Detection temperature changes from one place to another and approximate mapping Should be made available at the sink. 4. Tracking source of an event can be mobile.

Examples: -

• Deployment options: - 1. Fixed deployment Machinery Maintenance Application. 2. Random deployment large number of nodes from at aircraft over a forest fire.
• Maintenance Option
• Options for Energy Supply.

Challenges of Wireless Sensor Network: -

• Characteristic Requirements Type of Service: -

1. Wireless sensor network is expected to Provide meaningful information and / or actions about a Given Task
2. service type rendered by a Conventional Communication Network is evident- it moves bits from one place to another.
3. people want answers not numbers
4. New paradigms of using a search network are required alongwith New Ways of Thinking about the service of a network.

• Quality of service: -

1. closely related to network service
2. Traditional Quality of Service include bounded delay or minimum bandwidth are irrelevant When applications are tolerant to latency.
3. Bandwidth of the Transmitted Data is very small in the first place.
4. Delay is important When actuators are to be controlled in a real time fashion by a sensor network.
5. Packet Delivery Ratio is an insufficient metric.

• Fault Tolerance: -

1. Nodes may run out off energy or Might Be damaged 
2. wireless communication between 2 nodes can be permanently interrupted
3. wireless sensor network is able to tolerate faults search.

• Lifetime: -

1. Nodes will rely on Limited Supply of Energy
2. energy efficient way of operation of the wireless sensor node is Necessary.
3. solar cells are not powerful enough to Ensure Continuous operation of the network but can Provide some recharging of batteries 
4. , Lifetime of the network therefore has direct trade-offs against quality of service.
5. precise definition depends on the application at hand
6. time until the first node fails as the network lifetime.

• Scalability: -

1. since wireless sensor network might include large nodes, the employed architectures and protocols must be able to scale to the numbers.

• Wide range of densities: -

1. Number of nodes per unit area and density can vary considerably.
2. different application has different node density
3. Density is non homogeneous network so Should Adapt to search variations.

• Programmability: -

1. nodes alongwith processing of information theywill have to react flexibility on changes in Their task.
2. Should be programmable and programming must be changeable during operation. When New Task Becomes important fixed way of processing is insufficient information.

• Maintainability: -

1. wireless sensor network changes and The System Has to Adapt.
2. network has to maintain itself
3. Interact with external maintenance mechanism to Ensure its extended operation at a required quality

Required mechanism: -

• Multihop wireless communication: -

1. long distance communication is Possible only through multihop.
2. reduce total power required due to the use of intermediate nodes as relays

• Energy efficient operation

1. Forming of hotspots is an issue

• Auto Configuration: -

1. self location 
2. tolerate failing nodes
3. integrate new nodes

• Collaboration and in Network Processing: -

1. several nodes have to collaborate to detect on event
2. EC., to find the average temperature of an area.

• Data centric: -

1. Data Transfer Among Devices dealing with Common Data
2. EC., average temperature of an area.

• Address centric: -

1. Transfer of Data between 2 specific devices equipped with one network address.

• Locality: -

1. exploit trade-offs: 1. node density. 2. Energy Efficiency.

Sensor Network

Mobile Adhoc Networks and Wireless Sensor Network: - 

• self configuration is Crucial
• The Network is expected to work without manual management or configuration 
• Notion of Manet are Associated with wireless communication and wireless multihop SPECIFICALLY communication.
• The name indicates the mobility of participating nodes as a typical ingredient.

Applications and equipment: -

• The terminal can be fairly powerful with a comparably large battery
• needed due to human in the loop
• used for voice communication 
• Equipment has to be powerful enough to support Those Application 

Application Specific: -

• Many different application scenarios for wireless sensor network powerful enough to support Those application.

Application Specific: -

• Many different application scenarios for wireless sensor network Become Possible.
• EC., wireless sensor networks are conceivable with very different network densities from very sparse to very dense deployments.

Environment Interaction: -

• Wireless Sensor Networks have to interact with environment Their traffic characteristics can be expected to be very different from other human driven form of networks

Scale: -

• Wireless Sensor Networks have to scale to much larger numbers of entities than current adhoc networks.
• Requiring different more scalable solutions.

Energy: -

• In Both Wireless Sensor Networks and Manet's energy is a scare resource.

Self configurability: -

• self configure into connected networks.

Dependability and Quality of Service: -

• MANet- each node Should be fairly reliable 
• WSN - node is next to irrelevant 

Data centric: -

• Redundant deployment will make data centric protocols attractive in wireless sensor network.
• Data centric protocols are irrelevant to Manet

Simplicity and resource scarceness: -

• Sensor nodes are simple and energy supply is scarce then the operating and networking software must be kept in orders of magnitude simpler Compared To Today's desktop.
• Resources like memory Which is irrelevant for comparably heavyweight Routing Protocols as Those used in Manet is not available in arbitrary quantities Requiring new scalable resource efficient solutions.

Mobility: -

• Nodes moving around changing multihop routes, First Sensor network can be used to detect and observe a physical phenomenon. (Cause and events)., Secondhand is the sinks of information in th network.

Field Buses and Wireless Sensor Networks: -

• Field buses- network designed for operation under hard real time constraints.
• Built in Fault Tolerance 
• predominantly in Control Applications
• as part of control loop.
• Because of stringent hard realtime requirements. thesis networks are wired and Layer One, Two and 7 of the OSI are used.
• avoid communication over multi hop
•  avoid queuing delay

Enabling technologies for wireless sensor network

• building wireless sensor network is Possible with some fundamental advances in technologies 
• First- minimization / miniaturization of hardware
• smaller size chips have driven Power Consumption 
• particularly relevant to the microcontroller and memory chips
• more energy efficient
• reduced size and energy
• Lower cost Necessary to make redundant deployment of nodes affordable
• sensor node have to be Accompanied by Power Supply 
• high capacity batteries that last for long times 
• sensor node has a device called energy scavenging (recharging battery with the energy gathered from the environment.

ios 4

App Development Essentials: -

1. peers in smartphone market 
2. Remarkable technological achievements.

Anatomy of an iPhone 4: -

1. Sleek Device
2. 115.2mm long
3. 58.61 mm wide
4. 9.3mm deep.
5. 137 grams weight
6. GPRS
7. EDGE
8. 3G wireless support
9. digital compass
10. GPS
11. in accelerometer 
12. a gyroscope
13. A proximity sensor
14. at Ambient Light Sensor 
15. Bluetooth
16. WiFi
17. Multitouch Screen 
18. a vibration generator 
19. 5MP autofocus camera with built in flash 
20. 30 frame per second front facing camera
21. music 40 hrs; Video 10 hrs; talk non stop 14 hrs.

iOS 4: -

1. Os is called iOS4
2. Apple's Mac OS X operating system to run on the iPhone Adapted.
3. built on UNIX like foundation called Darwin 
4. Mach Kernel, Core Services Media and Cocoa Touch Layer Interface

 Display: -

1. 3.5 inch display
2. Resolution 960 * 640 pixels
3. displays 326 PixelsPerInch (ppi)
4. 800: 1 Contrast Ratio
5. In Plane Switching (IPS) LED
6. Capacitive Touch Screen 
7. Screen scratch, oil and fingerprint resistant coated surface oleophopic
8. Proximity Sensor -> automatically turns off the screen when you put the phone to your ear
9. Ambient Light Detection
10. Adjusts the brightness

Wireless Connectivity: -

1. WiFi connect at Either 802.11b; 802.11g; 802.11n speeds
2. Phone CALLS AT & T device supports GSM / EDGE (2G)
3. Faster speeds (UMTS) Universal Mobile Communications System
4. HSDPA High Sped Downlink Packet Access
5. HSUPA High Speed ​​Uplink -known as 3G; 7.2 Mbps.
6. Bluetooth v 2.1 Enhanced Data Rate

Wired Connectivity: -

1. 3.5mm headset jack - headphones or audio devices 
2. 30 pin dock - USB 2.0 connection for v synching and Battery Charging

Memory: -

1. 16 GB
2. 32GB 
3. flashdrive shape 
4. No additional memory cards

Camera: -

1. 5 MP autofocus StillCamera 
2. HD Video Resolution 720p 30 frames per second (fps)
3. LED flash 
4. VGA resolution 
5. 30 fps Front camera

Sensor: -

1. Proximity Sensor 
2. Accelerometer 
3. Three axis gyroscope
4. Ambient Light Sensor 

Location Detection: -

1. GPS Assisted GPS (A-GPS)
2. approximate location- cellular- WiFi information 

Central Processing Unit (CPU): -

1. Apple A4 system-on-chip; ARM Cortex A8 chip; with Imagination Technologies to Power VR graphics processing unit.
2. Cortex A8 designed by a British company ARM Holdings; based on ARMv7 processorArchitecture; low power requirements and high performance

Graphics Processing Unit: -

1. (Power VR SGX 535 GPU Imagination Technologies) handles iphone 4 Graphics
2. Support OpenGLES 1.1 / 2.0

Speaker and Microphone: -

1. Built in microphone and speaker
2. sound quality of speaker is poor

Vibration: -

1. vibrates to indicate the call
2. vibrate for application too

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