XBEE in API mode PRESENTED BY : NIKUNJ GANDHI (200811013) VARUN KUMAR DWIVEDI (200811011) 1
XBEE RADIO S DON T TELL ME ABOUT THE TECHNOLOGY TELL ME ABOUT THE APPLICATION --- TOM 2
WHAT S THE APPLICATION? Design and develop a multi-channel, wireless communication system for the purpose of modifying toys for children with disabilities XBee Protocol S w itch P ica x e X B e e M o d u le X B e e M o d u le P ica x e T o y Fig. 1. Application of XBEE Protocol http://www2.hawaii.edu/~allencha 3
WHAT S THE APPLICATION? Cont Parking lot automation Energy management solution Solution for building insurance Limitations in those applications 1) Bandwidth 2) Radio range 4
WHAT S THE TECHNOLOGY? 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
COMMUNICATION USING XBEE.. Fig. 3. Internal data flow diagram 7
COMMUNICATION USING XBEE 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
COMMUNICATION USING XBEE Cont.. The major problem in AT mode :- 2. For each module to communicate, a target 64 bit and 16 bit address has to be set at the module. 3. The change of these addresses, however, can be only done in the command mode. 4. That means rapid changes of transmit destinations are not possible, because there is the requirement of total over 2 seconds of the silence before entering command mode. 9
COMMUNICATION USING XBEE 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
COMMUNICATION USING XBEE Cont.. XBEE operation modes : - Fig. 4 Modes of Operation in XBEE 11
COMMAND MODE 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
AT COMMAND FORMAT 13
API OPERATION 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
API OPERATION (cont..) There are two modes of API operation 2. Standard (AP = 1) 3. Escaped (AP = 2) Fig. 5. Data frame structure (AP = 1) 15
API OPERATION 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
REMOTE CONFIGURATION 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
REFERENCES [1] Wikipedia Zigbee http://en.wikipedia.org/wiki/zigbee [2] Wikipedia - Bluetooth http://en.wikipedia.org/wiki/zigbee [3] Maxstream XBEE series manual [4] XBee /XBee-PRO OEM RF Modules [5] http://www2.hawaii.edu/~allencha 20