Using 7 segment on De1 Board

[Altera_Forum]

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]

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]

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]

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]

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]

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]

--- Quote Start ---  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]

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]

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]

--- 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]

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]

--- Quote Start ---  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]

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]

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