#9 Design a Handheld POV [Post Homework Here]

[ThePyroElectro]

A new lesson was posted today:
http://www.pyroelectro.com/edu/fpga/handheld_pov/

Post your homework answers here to compare with everyone else!

[Bingo600]

The homework looks like the one from lesson8

/Bingo

[ThePyroElectro]

The homework looks like the one from lesson8

/Bingo

I'll fix this + the schematic PDF (it says lesson8 as well) on sunday. Sorry

[Bingo600]

Seems like the schematic is fixed , but not the homework

/Bingo

[ThePyroElectro]

Seems like the schematic is fixed , but not the homework

/Bingo

They're all fixed now!

[Bingo600]

HOMEWORK QUESTION 1
Modify The ROM in lesson10’s VHDL code, so the POV message will be: HELLO!

I suppose you mean lesson9's ....

Code: Select all

   type num_array is array (0 to 31) of std_logic_vector(7 downto 0);
   constant led_message : num_array := (
      0  => "00000000",               --
      1  => "11111111",               --********
      2  => "00010000",               --   *
      3  => "11111111",               --********
      4  => "00000000",               --
      5  => "11111111",               --********
      6  => "10010001",               --*  *   *
      7  => "10000001",               --*      *
      8  => "00000000",               --
      9  => "11111111",               --********
      10 => "10000000",               --*
      11 => "10000010",               --*
      12 => "00000000",               --
      13 => "11111111",               --********
      14 => "10000000",               --*
      15 => "10000000",               --*
      16 => "00000000",               --
      17 => "11111111",               --********
      18 => "10000001",               --*      *
      19 => "11111111",               --********
      20 => "00000000",               --
      21 => "00000000",
      22 => "00000000",
      23 => "00000000",
      24 => "00000000",
      25 => "00000000",
      26 => "00000000",
      27 => "00000000",
      28 => "00000000",
      29 => "00000000",
      30 => "00000000",
      31 => "00000000"
   );



HOMEWORK QUESTION 2
How would the LED message change, if we used a faster clock signal to the CPLD, from the
555 timer?

I haven't build the pow (blush).
But i'd suppose either :
1: The letters would be narrower , as (with the same hand movement velosity) there is less time where the leds are on.
2: The on time would be so fast so it would look like a blur of red.

HOMEWORK QUESTION 3
What is a good clock frequency to use when building a hand-held POV? Why?

200Hz (5ms) - (video says 5us ... thats a tad fast for 200Hz)

At 200Hz the flicker isn't visible to the human eye.


/Bingo