RF Venue Control

1
RF Venue Control

• Matthew Bishop
• Michael Galdos
• ECE 4180 Fall 2006

2
Overview / Design Goals

• Concert halls and venues need to maintain patron
  counts
• Fire codes
• Useful for marketing, statistics, etc.
• Often many entrances/exits to a venue
• Need wireless transmissions from several
  locations to one base station to ease venue
  management

3
Project Design

• System consists of a satellite station, main
  station, microcontroller and compact PC
• Satellite station consists of a state machine and
  a radio transmitter/encoder
• Main station consists of a radio receiver/decoder
  and a microcontroller with a serial connection
• Main station is connected to a C application
  with a statistical GUI

4
Implementation Details

• RF transmitters/receivers and encoders/decoders
  ordered from DigiKey
• Various state machine parts also ordered from
  DigiKey
• Cypress PSoC evaluation board for serial
  communication
• Application developed using Visual Studio 2005
  with .NET Compact Framework 2.0

5
RF Transmitter Transmission

• Button press registered onto encoder inputs
• Encoder creates serial stream of data acceptable
  for RF
• Transmitter sends stream of data at 315 MHz to
  antenna

6
RF Transmitter State Machine

• Transmitter and receiver must learn secure code
  words from each other
• 8-step state machine handles logic for
  initializing inputs and sending code
• Once state machine completes, transmitter
  continually sends code word to antenna

7
RF Transmitter
8
RF Receiver

• Takes data in serial format from antenna at 315
  MHz
• Decodes serial stream into 8 parallel bits and
  holds output until a new transmission arrives
• 4 used bits of data sent to microcontroller for
  sending to host over serial

9
Cypress Microcontroller

• Assembly project that uses UART to send data over
  serial to host
• 4 bits of data from decoder first inverted and
  buffered to handle any voltage differentials
• Assembly code inverts again and outputs to serial
  port
• Serial port continuously streams input

10
RF Receiver
11
Application

• C .NET CF 2.0 application
• Reads data from serial port and increments or
  decrements counter based on value as well as
  record timestamp of value change
• Uses code that toggles certain variables so that
  data is not continuously counted
• Displays count value and also gives options to
  perform statistics on event data in database

12
Application Screenshots GUI
13
Application Screenshots Stats
14
Demo
15
Results

• Successful, secure communication over RF
• Project could be expanded to include multiple
  transmitters
• Range dependent on surrounding interference

16
Projected vs. Actual Time Line
17
Questions?