data collection u sing z igbee network
Download
Skip this Video
Download Presentation
Data Collection U sing Z igbee Network

Loading in 2 Seconds...

play fullscreen
1 / 18

Data Collection U sing Z igbee Network - PowerPoint PPT Presentation


  • 92 Views
  • Uploaded on

Data Collection U sing Z igbee Network. Timothy Melton Moscow, ID. Introduction. Problem: I wanted a way to monitor analog inputs to microcontrollers using a zigbee wireless network with a central gathering point

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Data Collection U sing Z igbee Network' - mikaia


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
data collection u sing z igbee network

Data Collection Using Zigbee Network

Timothy Melton

Moscow, ID

introduction
Introduction
  • Problem: I wanted a way to monitor analog inputs to microcontrollers using a zigbeewireless network with a central gathering point
  • Solution: Using three xbee brand transceivers and two pic32 microcontrollers I was able to setup a short range network for data monitoring and collection
hardware
Hardware
  • 3 Xbee 1mW w/Chip Antenna zigbeetranceivers
  • 1 XBee Explorer USB
  • 1 Personal computer w/serial terminal
  • 2 pic32mx4 microcontroller experimenter boards
xbee transceiver
Xbee Transceiver
  • RF Data Rate: 250 kbps
  • Indor/Urban Range:100 ft (30 m)
  • Transmit Power: 1 mW (+0 dBm)
  • Frequency Band: 2.4 GHz
  • Interfaces: I2C, SPI, UART
  • Uses Zigbee communication standard
    • IEEE 802.15.4
pic32mx4
PIC32MX4
  • Max Speed MHz: 80
  • Program Memory Size (KB): 512
  • RAM (KB): 32
  • A/D channels 16
  • RTCC Yes
  • UART 2
microcontroller layout
Microcontroller layout

Transmitter 2 (z2)

Transmitter 1 (z1)

collection layout
Collection layout

Collection Unit

configuration
Configuration
  • Microprocessor recievers
    • Set as endpoint device on network
      • Harcoded to send to router
    • UART to transceiver
    • 9600 BAUD
    • No flow control, 8-bit, no-parity, 1 stop bit
    • UART receive interrupt
  • Collector
    • Set as router
      • Broadcast messages
    • Transceiver to serial
    • Matching serial configuration in terminal
method
Method
  • Microcontroller units
    • Addressed z1 and z2
    • Read ADC measurements every second
    • Attach time to the measurments
    • Use fprintf statement to write to a buffer
    • Record past three readings
    • Wait for go signal from collector
    • Broadcast last three readings
  • Collector
    • Broadcasts go command with specific address
    • Recieves data from zigbee through uart into terminal
    • Displays readings in terminal
method continued
Method Continued
  • Since the microcontroller has a realtime clock and calendar getting the time was a matter of initalizing the time and then polling and storing it to a variable for the printf function
  • A polling timer was setup to check whether the one second ADC sample delay was met
  • To put the packet together for sending:

fprintf(uartbuff, “z1:: %d:%d - r1:%5.3f r2:%5.3f r3:%5.3f\r\n” hour, min, adc1, adc2, adc3);

“z1:: 14:22 – r1:01.334 r2:02.454 r3:05.287”

  • packet is generated each time the adc is read
  • Uartbuff3 = uartbuff2; uartbuff2 = uartbuff;
  • then assign to uartbuff each time through to keep track of last three readings.
method continued1
Method Continued
  • The Collector will send out command:

zx go

where x is the microcontroller address

  • A UART receive interrupt is generated in both receivers
  • Receivers parse which receiver is getting the go signal
  • Appropriate receiver sends three buffers to collector
problems
Problems
  • Configuring XBEE transceivers
    • Firmware flashing issues
      • Only certain available firmwares were able to be flashed
    • Working firmware limited network setup
      • Only able to implement router and endpoint configuration
    • Support for newer firmware hidden
areas for improvement
Areas for Improvement
  • Buying better xbeetrancievers
    • Newer models
      • Support more features (xbee pro, encryption, mesh networks)
    • More expensive models
      • Support longer ranges and have more antennae options
  • Collector time logging
    • Takes the burden off of the micro for keeping track of time
    • Prevents transmitting data from interfering with time information
    • Would keep track of when received instead of when gathered
  • Writing a program to collect data
    • Enables better storage options
      • Terminal outputs to screen
      • Enables parsing of data for better usage/readability
conclusion
Conclusion
  • Zigbee provides many options for setting up wireless networks
  • UART communication is an effective means to interface with transceivers
  • PIC32MX4 is very capable of receiving analog inputs and packetizing the data to be transferred over Zigbee.
ad