Re: Using 7 segment on De1 Board

Altera_Forum · ‎11-17-2013

Hello to every one,

I've just bought the DE1 board and i try to do some sample program with VHDL like put led on when switch is on and something similar.

I kindly ask you if you can tell me how i can set-up 7 segment display. Is necessary a multiplexer??

Best Regards

Michele

Altera_Forum · ‎11-17-2013

The 4 displays of the DE1 board are not multiplexed. They use 28 pins to drive each segment. In the reference manual you can see pin assigments for the 7 segments displays.

Altera_Forum · ‎11-17-2013

But for use it what i must do?

Of course i an output so i can declare it into entity like:

HEX0, HEX1 ........ OUT STD_LOGIC_VECTOR (0 TO 6)

But in architecture? I want for example that the display count how many SW are on if i do the assignment

LEDR <= SW led are on when switch is on but i don't find any assignment for the display can you help me pls?

Altera_Forum · ‎11-17-2013

To count how many '1's ( or '0's ) you may design a majority circuit. This code:

jurado1: process (t1)

variable m1 : unsigned (2 downto 0);

begin

m1:=TO_UNSIGNED(0,3);

for i in 0 to 3 loop

if (t1(i) = '1') then

m1:=m1+1;

end if;

end loop;

count <= m1;

end process jurado1;

count will have the numbers of '1's on vector t1 ( 4 bits ). I don't know how many '1's do want count. For a greater number of switch a sequential counter will be easier.

Of course you have to decode bcd number on count, to 7 segment code. If you count more than 9 '1's you'll need 2 digits, so you need a bin to bcd converter.

Altera_Forum · ‎11-17-2013

I posted an example for the DE1 in this thread:

http://www.alteraforum.com/forum/showthread.php?t=35687

Download the zip file and follow the instructions to build it. It includes code for driving the hex displays.

Cheers,

Dave

Altera_Forum · ‎11-18-2013

Thanks Dave, unfortunately (i know that you already hate me for all stupid problem that i posted on forum :) ) but our teacher impose us to use the 9.1 sp3 version

of Quartus II so when i try to lunch the file synth.tcl the console tell me that my version is older than the version in which you create the project! At the moment i want

to tell you "THANK YOU" for your help and kindly ask you another question then i hope that i ll be able to walk with my leg and start to do some experiment with the board......

consider that on february i must send a project to my teacher.....i am very delay but i have also other 3 exam to prepare! :(

Bertulus wrote on this post that i must create a majority circuit, what is it? It's not possible to work 7 segment display only a VHDL file??

I tried to do a "stupid" experiment for see that the output work like

HEX <= SW

like switch and led but i also now that is 7 segment display is a device completely different than switch and buttons.....can you tell me how i must do for see the component work?

Thanks a lot for your cooperation

Michele

Altera_Forum · ‎11-18-2013

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Thanks Dave, unfortunately (i know that you already hate me for all stupid problem that i posted on forum :) )

--- Quote End ---

So far your questions have not been stupid, so you're ok :)

--- Quote Start ---

but our teacher impose us to use the 9.1 sp3 version

of Quartus II so when i try to lunch the file synth.tcl the console tell me that my version is older than the version in which you create the project!

--- Quote End ---

I downloaded the zip and I see that the qwork/ folder was included in the zip. Just delete that folder and try again.

--- Quote Start ---

Bertulus wrote on this post that i must create a majority circuit, what is it? It's not possible to work 7 segment display only a VHDL file??

--- Quote End ---

Perhaps he misunderstood your request. You just want to be able to use the 7-segment display, right?

--- Quote Start ---

I tried to do a "stupid" experiment for see that the output work like

HEX <= SW

like switch and led but i also now that is 7 segment display is a device completely different than switch and buttons.....can you tell me how i must do for see the component work?

--- Quote End ---

Each segment in the display is a like LED. If you want to see numbers, then you have to turn on different segments. Look in the VHDL file with the example I posted (hex_display.vhd) and read the comments in there.

Cheers,

Dave

Altera_Forum · ‎11-19-2013

Thanks Dave, now the project work well! I just start to see your code! If i have other problem i post it on forum :)

Yes i want only use the 7 segment display :)

Thanks a lot for your cooperation

Michele

Altera_Forum · ‎11-22-2013

ok now i understand how the 7 segment display work. I try some test like sum HEX0 <= "0000000" + "1" and i saw that the result is not 1 :)

For sum two number into 7 segment display, i must use also clock?

Altera_Forum · ‎11-22-2013

--- Quote Start ---

ok now i understand how the 7 segment display work. I try some test like sum HEX0 <= "0000000" + "1" and i saw that the result is not 1 :)

--- Quote End ---

Right, because the 7-segment display is just a bunch of LEDs. If you want those LEDs to "mean" numbers, then you have to decode the number, i.e.,

HEX0 <= decode(number);

You could have your code written like this using a function call, or using a hex_display component as shown in the example you downloaded.

--- Quote Start ---

For sum two number into 7 segment display, i must use also clock?

--- Quote End ---

No, but its generally useful to use a clock.

In the case of your "tests" just output to the hex display the switch settings or the key settings


u4: hex_display
    port map(
        hex     => hex_data_d,
        display => hex_d
    );
-- Drive with the switches
hex_data_d <= sw(3 downto 0);
-- Drive with the push buttons
-- hex_data_d <= key(3 downto 0);

Cheers,

Dave

Altera_Forum · ‎11-22-2013

for assignment a variable to an hardware component, for example an X input with key / sw

is enough do for example:

signal X: KEY[0]

Altera_Forum · ‎11-22-2013

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for assignment a variable to an hardware component, for example an X input with key / sw

is enough do for example:

signal X: KEY[0]

--- Quote End ---

Not quite. There's two ways you could do something like this;


signal x : std_logic;
-- "Read" the state of key(0) into x
x <= key(0);

or the shorthand version


alias x is key(0);

Note: VHDL is case insensitive, so writing capitals makes no difference. A typical "convention" is to write generics in capitals, but even that is not universal.

Cheers,

Dave

Altera_Forum · ‎11-28-2013

Hi Dave,

Thanks a lot for all your help, now i start to use seriously the board and i understood most of their function but there is another request, for that exam i ll prepare

a project. I can decide what prepare and with my colleague we decide to create a simply game like ping pong / arkanoid. I find on youtube video about game like that

but in my book i didn't find any reference about the library that i must use and also a manual of that library. My request is referred to the graphic part of my project.

Thanks a lot for your cooperation

Cheers

Michele

Altera_Forum · ‎11-29-2013

Hi Michele,

I have not needed to implement graphics. This site has some examples

http://users.ece.gatech.edu/~hamblen/altera/altera.htm

I have not looked at or used this code.

Cheers,

Dave