Projects

• TV signal generator

  This project was developed as FPGA programming training. Additionally that time I needed simple and portable TV generator during my previous job.
  TV generator is based on CPLD EPM3064ALC44 from Altera company. It generates black-and-white TV signal that satisfies standard used in former Sovietunion (As I remember, it is B/G standard).
  Set of generated signals includes: brightness bars from black to white, coordinate nets, chess field. Signals can be switched by button "Mode". Image can be inverted by button "Inv".
  In the archive below you will find schematics and Verilog code. Note, that this schematics can be used as reference, but not as ready to use one. You should add decoupling capacitors. Pin numbers can differ after project is compiled. Additionally, you should adjust summing resistors for B, G, R and Sync signals. Unfortunately, now I have no prototype and I forgot exact values.

  Project documentation (Schematics, Verilog code, timing parameters)

  Prototype
  Grayscale bars mode	Inverse grayscale bars mode
  Chessboard mode
  Net mode	Inverse net mode

• Color TV generator in PAL system

  This project is extension of previous one. Here I tried to develop color TV signal generator using the same chip. additionally external 8.86MHz generator for color carrier frequency is required.
  Unfortunately, due to simplicity, there are several things not satisfying to standard. The carrier frequency is not locked on begin of every raw. (On professional monitors you can see color signal to "run" in vertical direction). Color signal is sampled on 16 levels only.
  Idea of this simple color signal generating was borrowed from journal "Radio" [1]. Note, that this schematics can be used only as reference. You should adjust summing resistors for B, G, R and Sync signals. Additionally you should adjust resistors forming DAC for color signal. Unfortunately, now I have no prototype and I forgot exact values.
  File "tvcolorbars.v" consist original project, and in file "tvcolorbars_colorfields.v" I tried to extend functionality of TV color generator by adding blue, green, red colors and their combinations fields. Switching between signals can be made by "Mode" button.

  Project documentation (Schematics, Verilog code)

  Colorbars mode (strange, but my old camera made green bar as salade one :-( )

  Color bars TV signal on the scope

   

  Reference
  [1]. Yablonsky O. Encoder PAL. Radio, 1992, N8, pp.37-39

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