Question

The stepper motor controller will run in full step mode. That means the clockwise sequence will be

Winding1	Winding2	Winding3	Winding4
1	0	0	0
0	1	0	0
0	0	1	0
0	0	0	1
Repeat the pattern

The counterclockwise sequence will be

Winding1	Winding2	Winding3	Winding4
0	0	0	1
0	0	1	0
0	1	0	0
1	0	0	0
Repeat the pattern

Design a stepper motor controller for half step mode in VHDL using Xilinx Vivado.

The following will be your inputs:

               CLOCK

               RESET

               DIRECTION – An input that determine the direction. HIGH for clockwise and LOW for counterclockwise.

Answer 1

library IEEE;
use IEEE.STD_LOGIC_1164.all;
use ieee.std_logic_arith.all;

entity stepper_half_step is
     port(
         CLOCK : in STD_LOGIC;
         RESET : in STD_LOGIC;
         DIRECTION : in STD_LOGIC;
         Q : out STD_LOGIC_VECTOR(3 downto 0)
         );
end stepper_half_step;

architecture stepper_motor of stepper_half_step is
begin

    stepper_motor : process (CLOCK,RESET) is
    variable a : std_logic_vector (2 downto 0) := "000";
    begin
        if (RESET='1') then
            if (rising_edge (CLOCK)) then
                a := a + 1;
            end if;
        end if;
     
        case a is
        if (DIRECTION='1') then
               when "000" => Q <= "1000";
               when "001" => Q <= "0100";
               when "010" => Q <= "0010";
               when "011" => Q <= "0001";
        end if;
        if (DIRECTION='0') then
               when "100" => Q <= "0001";
               when "101" => Q <= "0010";
               when "110" => Q <= "0100";
               when others => Q <= "1000";
        end if;
        end case;
    end process stepper_motor;

end stepper_motor;