VHDL error - natural type does not match string literal

[Altera_Forum]

Hi, 

 I am trying to make a simple program which will turn on the green LED when the Key(0) is pressed and when we leave the key, it will be switched off.   I am getting this error in the code for some reason though - Error (10515): VHDL type mismatch error at pract.vhd(36): natural type does not match string literal   library ieee; use ieee.std_logic_1164.all; use ieee.std_logic_arith.all; use ieee.numeric_std.all; use ieee.std_logic_unsigned.all;  entity pract is  port (  iKEY : in std_logic_vector(0 downto 0);  oLEDG: out std_logic_vector(2 downto 0) ); end entity pract;  architecture behav of pract is    signal sel : std_logic_vector(0 downto 0) := "0"; begin    p1 : process(iKEY) begin  if(rising_edge(iKEY(0))) then  sel <= sel + "1"; end if;  end process;  p2 : process(iKEY)  begin  case sel is  when "0" =>  oledg("000") <= '0'; -- this is where i get the error when "1" =>  oLEDG("000") <= '1'; end case;  end process;   end behav;

[Altera_Forum]

Your output is 3-bits 

 oLEDG: out std_logic_vector(2 downto 0)  you need to assign a 3-bit value, eg.,  oLEDG <= "111";  or   oLEDG <= "000";  If you want to just assign to 1-bit, lets say bit 0, then you can do  oLEG(0) <= '1';  Note that '1' is a 1-bit std_logic value, and "111" is a 3-bit std_logic_vector value.  Cheers, Dave

[Altera_Forum]

Hey, 

 I edited the code but I have the same error -  Error (10515): VHDL type mismatch error at pract.vhd(36): natural type does not match string literal Error (10515): VHDL type mismatch error at pract.vhd(36): std_ulogic type does not match string literal   case sel is  when "0" =>  oLEDG("000") <= "000"; when "1" =>  oLEDG("000") <= "111"; end case;

[Altera_Forum]

Look at my code again, then look at your code ... what did you forget to change? Hint, what is to the left of <=.

[Altera_Forum]

Thank you very much. It works :D

[Altera_Forum]

Never use these libs BOTH: 

use ieee.std_logic_arith.all; use ieee.numeric_std.all;  Better use only numeric_std instead.