XB EE in API mode PRESENTED BY : NIKUNJ GANDHI (200811013) VARUN - PowerPoint PPT Presentation

XB EE in API mode PRESENTED BY : NIKUNJ GANDHI (200811013) VARUN KUMAR DWIVEDI (200811011) 1

XB EE RADIO’S “ D ON’T T ELL M E A BOUT T HE T ECHNOLOGY T ELL M E A BOUT T HE A PPLICATION” --- TOM 2

W HAT’S T HE A PPLICATION?  Design and develop a multi-channel, wireless communication system for the purpose of modifying toys for children with disabilities XBee Protocol XBee XBee Switch Picaxe Picaxe Toy M odule M odule Fig. 1. Application of XBEE Protocol 3 http://www2.hawaii.edu/~allencha

W HAT’S T HE A PPLICATION? Cont…  Parking lot automation  Energy management solution  Solution for building insurance  Limitations in those applications 1) Bandwidth 2) Radio range 4

W HAT’S T HE T ECHNOLOGY? What do we want from Technology?  Guarantee for the high reliability  Protects against network intrusion  Long wireless range  Low power  Compact  Extensive option of controlling and reducing battery drainage. 5

WHAT’S THE TECHNOLOGY? Cont.. Fig 2.1. Official Bluetooth logo Fig 2.2. Official Wi-Fi logo Fig 2.3. Official Zigbee logo 6

C OMMUNICATION U SING X BEE .. Fig. 3. Internal data flow diagram 7

C OMMUNICATION U SING X BEE Cont..  XBEE module support both transparent & API serial interface.  When operating in transparent mode, the modules act as a serial line replacement. It operates in a similar way to e.g. modems.  The communication done by AT mode is either a fixed, single target or broadcast. 8

C OMMUNICATION U SING X BEE Cont.. The major problem in AT mode :-  For each module to communicate, a target 64 2. bit and 16 bit address has to be set at the module. The change of these addresses, however, 3. can be only done in the command mode. That means rapid changes of transmit 4. destinations are not possible, because there is the requirement of total over 2 seconds of the silence before entering command mode. 9

C OMMUNICATION U SING X BEE Cont..  AT mode can be used in mainly point to point links, such as remote controls for TV or any other applications where XBees can act as a replacement of serial cable. But in addition to that, it is possible to use it for sensors that are reporting their status to a single master. 10

C OMMUNICATION U SING X BEE Cont.. XB EE operation modes : -  Fig. 4 Modes of Operation in XBEE 11

C OMMAND M ODE In a command mode, command can be  issued to configure the device, retrieve the device configuration or run a network discovery To access the command mode, there has to  be one second of silence, then sequence of three pulses (+++) has to be sent within one second and than another one second of silence is required. On entering command mode module sends  ‘OK\r’ to UART. 12

A T C OMMAND F ORMAT 13

A PI O PERATION  API is the more sophisticated option of the communication with the module.  API firmware uses structured packet interface to communicate via UART.  Data wrapped together with commands, addressing and status information.  API allows programmer’s ability to change the parameters without entering into command mode. 14

A PI O PERATION (cont..) There are two modes of API operation  Standard (AP = 1) 2. Escaped (AP = 2) 3. Fig. 5. Data frame structure (AP = 1) 15

A PI O PERATION  When sending or receiving a UART data frame, specific value must be escaped so they do not interfere with data frame sequence. Fig. 6. Data frame structure (AP = 2) 16

API TYPES  The cmdID frame (API Identifier) indicates which API message will be contained in the cmdData frame (identifier specific data). 17

API TYPES  Modem status :-  API Identifier :- 0x8A  RF module status messages are sent from the module in response in response to specific conditions. 18

R EMOTE C ONFIGURATION  Any device running on API is capable of configuring any remote device within its current PAN.  This is done by sending a ‘Remote AT Command Request’.  If the acknowledge is requested, the remote node will reply with ‘Remote Command Response’ frame. 19

R EFERENCES [1] Wikipedia –Zigbee http://en.wikipedia.org/wiki/ZigBee [2] Wikipedia - Bluetooth http://en.wikipedia.org/wiki/ZigBee [3] Maxstream XB EE series manual [4] XBee™/XBee-PRO™ OEM RF Modules [5] http://www2.hawaii.edu/~allencha 20