ECE 354 Spring 2006

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ECE 354Spring 2006

• Lab 2 Capturing and Displaying Digital Image

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Big Picture Introduction

• Capture an image using a digital camera
• Download image data to NIOS II serially through
  the use of a UART
• A handshaking protocol will be used to
  communicate with digital camera
• Display the image on a CRT monitor with the use
  of a VGA controller
• Perform simple image processing
• Primarily written in C code
• Use a preexisting SOPC system with some slight
  modifications

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Additional Hardware

• ITM-C-328 Serial Color Digital Camera
• Serial Connector and Cable
• CRT Monitor

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Skills to learn

• Integrate code with preexisting code
• Understanding previously written code
• Connect to a device that you did not design
• Writing a communication protocol to somebody
  elses specifications

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Steps taken to complete project

• Begin by looking over ITM-C-328 camera
  documentation
• Plan out the series of events needed to
  communicate with the camera
• Write a C program to send a simple request
  message and receive a message in return
• Build up the program until ready to receive image
  data
• Image data should be stored in one continuous
  buffer in SDRAM (example char received64)
• Gain knowledge of how the DE2_NIOS_HOST_MOUSE_VGA
  project displays an image to the CRT monitor
• Use that knowledge to display your image
• Finally have fun performing image processing

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Communicating with the camera

• Communication with the camera is accomplished
  through a series of commands
• A single command consists of 6 continuous
  single-byte RS-232 transmissions
• A listing and description of the command set can
  be found in ITM-C 328_Manual.pdf

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Communicating with the camera (continued)

• This is the command protocol to receive an
  uncompressed snapshot picture
• Initial command to configure preview image size
  and color type
• Snapshot command takes a snapshot and stores data
  in camera buffer
• Get picture is used to transfer image data to
  host
• Your task is to implement this in C code

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Information for C program

• To write/read to/from the UART
• fd open(/dev/uart, O_RDWR O_NONBLOCK, 0)
• charReceived read(fd, to, length)
• write(fd, from, length)
• I recommend looking over section II of the
  NIOS II Software Developers Handbook
• A blocking read holds the program until the read
  operation completes with the length you specify
• Think about why a nonblocking read is needed

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Recommended C code functions

• A function to
• Establish a connection with the camera (Sync
  function)
• Send a message to the camera
• Receive and check a message from the camera
• Receive image data from camera
• Print bits of a byte received (debugging)
• Print hex equivalent of a message received
  (debugging)

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A little help

• Use the form on the bottom of this slide to
• hold messages that will be sent to camera
• hold messages to check received messages against
• The message can be written to the UART in the
  following way write(fd, SYNC, 6)

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Additional information

• The image should be 2-bit gray scale with a
  resolution of 640x480
• Uncompressed image
• I recommend starting with the smallest image
  resolution and work from there

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Overview of DE2_NIOS_HOST_MOUSE_VGA project

• Implements a monochrome display, with a preloaded
  image, where the user can draw on it with a mouse
• USB mouse should be connected USB HOST port
• CRT monitor should be connected to the VGA port
• You will integrate your code so that the project
  displays the image received from digital camera

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Displaying image through VGA controller

• Look through VGA.h for VGA functions
• Write C code similar to that shown below that
  calls functions from VGA.h to display each pixel
• It is your job to come up with an equation to
  check each pixel in your receive buffer

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Image Processing

• It is required that you implement two forms of
  image processing
• Recommendations include
• Add timestamp onto image
• Counter to keep track of number of pictures taken
• Rotate, mirror, invert image
• Simple edge detection (challenging)
• Detect changes in images (challenging)

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Where does this project lead?

• Next lab will be on the topic sending data over a
  network
• Sending image between DE2 boards
• Using computer networking knowledge learned from
  Professor Ganzs course
• Dont worry if you have not taken computer
  networking

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References

• Camera documentation (ITM-C-328)
• http//www.tdc.co.uk/camera/
• Information and Datasheets
• DE2_NIOS_HOST_MOUSE_VGA project
• NIOS II Software Developers Handbook
• http//www.altera.com/literature/lit-nio2.jsp

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Hints

• You may need to slightly modify the SOPC system
  of the MOUSE_VGA project
• Set the initial baud rate to what the camera
  initially wants
• Attend my lab hours and ask lots of questions

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Questions and Comments