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Similar to A zigbee wireless sensor network and multiple way bus communication meduim can bus
A zigbee wireless sensor network and multiple way bus communication meduim can bus
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- 2. To transmit thedata from CAN transmitter to CAN receiver and simultaneously from Zigbee transmitter to receiver.
- 3. BLOCK DIAGRAM A TEMPERATURE T M LCD SENSOR E G CAN FIRE A CONTROLLER AND DRIVER SENSOR 3 2 POWER ZIGBEE PC RECEIVER SUPPLY MAX23 A ZIGBEE T CAN TRANSMITTER 2 CONTROLLER AND DRIVER M E G DC MOTOR LCD A L293D 3 2
- 4. LM35 is a precision IC temperature sensor with its output proportional to the temperature (in oC). The operating temperature range is from -55°C to 150°C.
- 5. This fire sensorcircuit exploits the temperature sensing property of an ordinary signal diode IN 34 to detect heat from fire.
- 6. Mini-Computer Microprocessor The Brains Arithmetic Logic Unit (ALU) Control Unit Program/ Data Storage Peripherals (Input/Output) Low-Cost
- 8. High-performance, Low-power AVR8 bit microcontroller RISC architecture The ATmega32 has 32 GPIO 32K Bytes of In-System Self-Programmable Flash memory 2 KB RAM. 1024 Bytes EEPROM Programmable Serial USART
- 10. Bit 1 –Z: Zero Flag Bit 0 – C: Carry Flag Bit 7 – I: Global Interrupt Enable Bit 5 – H: Half Carry Flag Bit 6 – T: Bit Copy Storage Bit 4 – S: Sign Bit, S = N ⊕V Bit 2 – N: Negative Flag Bit 3 – V: Two’s Complemenr Overflow Flag Bit 1 – Z: Zero Flag Bit 0 – C: Carry Flag
- 13. Conventional multi-wire looms CAN bus network vs.
- 14. NODE MCU I/O CAN CONTROLLER NODE CAN NODE TRANSCEIVER 120 ohms 120 ohms
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- 16. APPLICATION LAYER PRESENTATION LAYER SESSION LAYER TRANSPORT LAYER NETWORK LAYER DATA LINK LOGICAL LINK CONTROL LAYER MEDIUM ACCESS CONTROL PHYSI PHYSICAL SIGNALING CAL PHYSICAL MEDIUM ATTACHMENT LAYER MEDIUM DEPENDENT INTERFACE
- 17. • The CANprotocol controller outputs a serial data stream to the logic TXD input of the MCP2551. The corresponding TRANSMIT recessive or dominant state is output on the CANH and CANL pins. • The MCP2551 receives dominant or recessive states on the same CANH and CANL pins as the transmit occurs. These states are output as logic levels on the RECEIVE RXD pin for the CAN protocol controller to receive CAN frames. • A logic „1‟ on the TXD input turns off the drivers to the CANH and CANL pins and the RECESSIVE pins “float” to a nominal 2.5V via biasing resistors. STATE • A logic „0‟ on the TXD input turns on the CANH and CANL pin drivers. DOMINANT
- 18. CONFIGURATION MODE NORMAL MODE SLEEP MODE LISTEN –ONLY MODE LOOP BACK MODE
- 19. CAN 2.0A (“standardCAN” 11-bit ID) Data Frame. CAN 2.0B (“extended CAN” 29-bit ID) Data Frame. 19
- 20. CSMA/CD NDA –Carrier Sense Multiple Access/Collision avoidance by Non Destructive arbitration 20
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- 22. What is ZigBee? TechnologicalStandard Created for Control and Sensor Networks Based on the IEEE 802.15.4 Standard Created by the ZigBee Alliance Wireless personal area networks (WPANs) High level communication Frequency band up to 2.5 GHz
- 23. Data rates of 20 kbps and up to 250 kbps Support for Low Latency Devices CSMA-CA Channel Access Handshaking Low Power Usage consumption 3 Frequencies bands with 27 channels Extremely low duty-cycle (<0.1%) Supports large number of nodes Easy to deploy Very long battery life Secure Low cost Can be used globally
- 25. IEEE 802.15.4 Physical layer •Activation and deactivation of the radio transceiver •Energy detection •Link quality indicator •Channel frequency selection •Data transmission and reception •CSMA-CA MAC layer •Generating network beacons •Synchronizing •PAN association and disassociation •Device security •GTS mechanism •Reliability
- 26. IEEE Zigbee 802.15.4 device roles device roles FFD RFD Coordinator Router End device PAN Coordinator device coordinator
- 27. Data transfer models Peer to peer Star mesh
- 28. Functional Overview •Superframe structure • Data transfer model • Frame structure • Improving probability of successful delivery • Power consumption considerations • Security
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- 32. Discard route request B req. C route a req. route route reply T S req. rou te r route eq. D rou te r eq. Unicast Broadcast Without routing capacity
- 33. MAX232 Schematic Diagram
- 34. CONCLUSION AND FUTURESCOPE In this application CAN uses multiple transmitter nodes to acquire data from sensors and transmit the data in packets over a CAN bus. Each transmitter consists of an AT Mega32 micro controller. The CAN packets are received by a single receiver node and stored to a secure digital card (SD Card) by using SPI protocol.
Editor's Notes
- #3 The main objective of this project is to transmit the data from can transmitter to can receiver and simultaneously to Zigbee transmitter to receiver. Whenever the temperature is increased /obstacle is detected the dc motor will automatically starts and vice-versa
- #11 The Status Register contains information about the result of the most recently executed arithmetic instruction. This information can be used for altering program flow in order to perform conditional operations.
- #14 CAN is an important embedded protocol-Primarily automotive, but used in many other places. With the use of CAN, point-to-point wiring is replaced by one serial bus connecting all control systems. This is accomplished by adding some CAN-specific hardware to each control unit that provides the "rules" or the protocol for transmitting and receiving information via the bus. Invented by Robert Bosch GmbH Asynchronous Serial Bus Absence of node addressing Message identifier specifies contents and priority Lowest message identifier has highest priority Non-destructive arbitration system by CSMA with collision detection Multi-master / Broadcasting concept Sophisticated error detection & handling system Industrial and Automotive Applications Number of nodes – not lmtd by the protocolNo node addressing,msgidspecifiers,contents n priorityEasy connection /disconnection of nodesBroadcast /multicast capability
- #15 The nodes are connected to the bus in a wired-and fashion: if just one node is driving the bus to a logical 0, then the whole bus is in that state regardless of the number of nodes transmitting a logical 1.Max. transfer rate of 1000 kilobits per second at a maximum bus length of 40 meters or 130 feet when using a twisted wire pair which is the most common bus medium used for CAN. Message length is short with a maximum of 8 data bytes per message and there is a low latency between transmission request and start of transmission. The messages are protected by a CRC type checksum
- #16 •These are the bus levels according to ISO-IS 11898. A recessive bit is represented by both CAN bus lines driven to a level of about 2.5 V so that the differential voltage between CAN_H and CAN_L is around 0 V.•A dominant bit is represented by CAN_H going to about 3.5 V and CAN_L going to about 1.5 V. This results in a differential voltage for a dominant bit of about 2V.
- #17 ISO11898 is the international standard for high-speed CAN communications Many network protocols are described using the seven layer Open System inter connection (OSI) model. The Controller Area Network (CAN) protocol defines the Data Link Layer and part of the Physical Layer in the OSI model. The remaining physical layer (and all of the higher layers) are not defined by the CAN specification. The physical layer uses differential transmission on a twisted pair wire. The bus uses Non-Return To Zero (NRZ) with bit-stuffing.These other layers can either be defined by the system designer, or they can be implemented using existing non-proprietary Higher Layer Protocols (HLPs) and physical layers.The Data Link Layer is defined by the CAN specification.The Logical Link Control (LLC) manages the overload control and notification, message filtering andrecovery management functions. The Medium Access Control (MAC) performs the data encapsulation/decapsulation,error detection and control, bit stuffing/destuffing and the serialization and deserialization functions.ISO-11898 specifies the physical layer to ensure compatibility between CAN transceivers.The Physical Medium Attachment (PMA) and MediumDependent Interface (MDI) are the two parts of the physical layer which are not defined by CAN. The Physical Signaling (PS) portion of the physical layer isdefined by the CAN specification. The system designer can choose any driver/receiver and transport medium as long as the PS requirements are met.
- #19 INTERFACES WITHN MC VIA SPI to simplify applications that require interfacing with can bus.MCP2515 HAS 5 MODES OF OPRATION:CONFIGURATION MODEThe MCP2515 must be initialized before activation. This is only possible if the device is in the Configuration mode. Configuration mode is automatically selected after power-up or a reset.NORMAL MODENormal mode is the standard operating mode of the MCP2515. In this mode, the device actively monitors all bus messages and generates acknowledge bits, error frames, etc. This is also the only mode in which the MCP2515 will transmit messages over the CAN bus.SLEEP MODEThe MCP2515 has an internal Sleep mode that is used to minimize the current consumption of the device. The SPI interface remains active for reading even when the MCP2515 is in Sleep mode, allowing access to all registers.LISTEN –ONLY MODEListen-only mode provides a means for the MCP2515 to receive all messages. Listen-only mode is a silent mode, meaning no messages will be transmitted while in this mode (including error flags or acknowledge signals).LOOP BACK MODELoopback mode will allow internal transmission of messages from the transmit buffers to the receive buffers without actually transmitting messages on the CAN bus. This mode can be used in system development and testing
- #20 Note 1: It is worth noting that the presence of an Acknowledgement Bit on the bus does not mean that any of the intended addressees has received the message. The only thing we know is that one or more nodes on the bus has received it correctlyNote 2: The Identifier in the Arbitration Field is not, despite of its name, necessarily identifying the contents of the message.SOF – Start of FrameIdentifier – Tells the content of message and priorityRTR – Remote Transmission Request IDE – Identifier extension (distinguishes between CAN standard,11 bit identifier, and CAN extended, 29 bit identifier.)DLC – Data Length CodeData – holds up to 8 bytes of dataCRC – “Cyclic Redundant Check” sumACK – AcknowledgeEOF – End of FrameIFS – Intermission Frame Space. Minimum number of bits separating consecutive messages.
- #22 Arbitration limits bus speed. Maximum speed = 2 x tpdtpd = propagation delay of electrical medium
- #26 Physical layer •a transmitter shall be capable of transmitting at least –3 dBm (0.5 mW), normally at 0 dBm (1 mW) •a receiver shall have a receiver maximum input level greater than or equal to –20 dBm (0.01 mW) Physical layer • 2450MHz is the most commonly used band for WSNs because: • it’s available worldwide without need for licensing • it has highest data rate achieved with simplest modulation • Sub1-GHz bands (915/868 MHz) provide better signal range than 2.4 GHz bandwhen starting the network the coordinator scans pre- configured channels and choose one with least activity detected • when joining the WPAN, a device scans through the given set of channels and report discovered networks to higher layers to permit joingenerating network beacons if the device is a coordinator • synchronizing to network beacons • supporting PAN association and disassociation• supporting device security • employing the CSMA-CA mechanism for channel access • handling and maintaining the GTS mechanism • providing a reliable link between two peer MAC entities
- #27 An ffd is capable of performing all duties described in IEEE standard and can accept any role in the network.anrfd has limited capabilities.foreg. An ffd can communicate with any otherdevice in a network,but an rfd can talk only with an ffd device.rfd devices are intended for very simple aplications such as turning on or off a switch.the processing power and memory size of rfd devices are normally less than those of ffd devicesDevice roles: in an ieee 802.15.4 n/w,anffd device can take three different roles:coordinator,pan coordinator and device.A coordinator is an ffd device that is capable of relaying messages.if the coordinator is also the principal controller of a personal area network(pan)it is called a pan coordinator.if a device is not acting as a coordinator,it is simply called a device.The zigbee standards uses slightly different terminology.azigbee coordinator is an ieee 802.15.4 pan coordinator……A zigbee end device has the least memory size and fewest processing capabilitiesandfeatures.an end device is least expensive device in the n/wThere are three different types of ZigBee devices:ZigBee coordinator (ZC): The most capable device, the coordinator forms the root of the network tree and might bridge to other networks. There is exactly one ZigBee coordinator in each network since it is the device that started the network originally. It is able to store information about the network, including acting as the Trust Centre & repository for security keys.ZigBee Router (ZR): As well as running an application function, a router can act as an intermediate router, passing on data from other devices.ZigBee End Device (ZED): Contains just enough functionality to talk to the parent node (either the coordinator or a router); it cannot relay data from other devices. This relationship allows the node to be asleep a significant amount of the time thereby giving long battery life. A ZED requires the least amount of memory, and therefore can be less expensive to manufacture than a ZR or ZC.
- #28 Star: n/w is simple in setup and deploymentData forwarding is possible only by coordinator(two hops only)Coverage area is limited by one hop transmission rangePeer to peer: data frames can be delivered via several intermediate nodeLarge spatial areas can be covered by a single n/wComplex packet routing algorithm are required
- #29 Superframe structure • thisstandard allows the optional use of a superframe structure. The format of the superframe is defined by the coordinator. The superframe is bounded by network beacons sent by the coordinator and is divided into 16 equally sized slotsTypes of data transfer transactionsDevice to coordinator,coordinator to device,device to device
- #30 In beacon-enabled networks, the special network nodes called ZigBee Routers transmit periodic beacons to confirm their presence to other network nodes. Nodes may sleep between beacons, thus lowering their duty cycle and extending their battery life.In non-beacon-enabled networks, an unslotted CSMA/CA channel access mechanism is used. In this type of network, ZigBee Routers typically have their receivers continuously active, requiring a more robust power supply.Because ZigBee can activate (go from sleep to active mode) in 15 msec or less, the latency can be very low and devices can be very responsive — particularly compared to Bluetooth wake-up delays, which are typically around three seconds. Because ZigBees can sleep most of the time, average power consumption can be very low, resulting in long battery life.
- #31 In this mode, the network coordinator will periodically "wake-up" and send out a beacon to the devices within its network. This beacon subsequently wakes up each device, who must determine if it has any message to receive. If not, the device returns to sleep, as will the network coordinator, once its job is complete. Non-beacon mode, on the other hand, is less coordinated, as any device can communicate with the coordinator at will. However, this operation can cause different devices within the network to interfere with one another, and the coordinator must always be awake to listen for signals, thus requiring more power.In any case, ZigBee obtains its overall low power consumption because the majority of network devices are able to remain inactive over long periods of time.
- #32 ZigBee standard defines the Data Link Controller (DLC) layer, Network layer (NWK) and ZigBee profiles. Profiles are an agreement on messages, message formats and processing actions.There are two types of ZigBee Profiles:Device Profile: This profile describes how general ZigBee device features are implemented, such as Binding, Device Discovery and Service Discovery.Application Profile: This profile is application specific and consists of a list of ZigBee Device Descriptions. Each of the descriptions work together to form an application.
- #33 The route discovery in a ZigBee network is similar to the AODV routing protocol Links with lower cost will be chosen into the routing path. The cost of a link is defined based on the packet delivery probability on that linkRoute discovery procedure The source broadcasts a route request packet Intermediate nodes will rebroadcast route request if They have routing discovery table capacitiesThe cost is lowerOtherwise, nodes will relay the request along the treeThe destination will choose the routing path with the lowest cost and then send a route reply