Wireless Security System

1
Wireless Security System
Noel Campbell Vivek Shah Raymond Tong TA Javier
Castro
2
Video Surveillance Block Diagram
3
Video Capture Overview
Y 70
Clock_27MHz
Y isolator
8
Clock_27MHz
Dual-Port Block Memory
WE
ADV7185
Memory Controller
X
Camera
ADDR
Composite In
tv_in_ycrcb 190
Y
20
ycrcb 290
30
tv_clock
encode_busy
writing_memory
NTSC Decoder
Async FIFO
RGB
YCrCb to RGB Converter
Display
Syncing and blanking signals
Z
VGA Controller
4
Technical Considerations

• Synchronization of data
• ADV7185 clock vs lab kit 27 MHz clock
• Displaying data in VGA
• Acquire 240 X 240 real time video
• Write data to block memory then continuously read
  from it
• Memory Controller
• Write a frame worth of data into block memory for
  encoding and transmission

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Video Compression
Discrete Cosine Transform
512 bits/block
56 bits/block
Inverse Discrete Cosine Transform
6
Video Encoder
7
Wireless Transmission

• Data is sent serially from the labkit to the
  wireless kit
• Data is assembled into packets and sent from
  camera-end to fixed-end via CC2420 radio
• Data is then sent serially from receiver wireless
  kit to the receiver labkit

8
Transmitter
from encoder
Transmitter Control Unit
Radio Transmitter
80 x 900 Dual Port BRAM
80
Shift Register
RS232 Sender
serial cable
8
to receiver
FPGA
microcontroller
9
Receiver
from transmitter
Transmitter Control Unit
Radio Receiver
80 x 900 Dual Port BRAM
80
RS232 Receiver
Shift Register
serial cable
to decoder
FPGA
microcontroller
10
Video Decoder
11
Video Display Overview
Clock_27MHz
to all modules
Y 70
RGB
Dual-Port Block Memory
YCrCb to RGB Converter
8
Display
Delay
Z
Addr
X
Z
Syncing and blanking signals
decode_done
VGA Controller
Memory Controller
Only chrominance (Y) is important if displaying
grayscale image