include 16f628_20
include delay_20mc
include jstepper


CMCON = 7    -- set portA to normal digital IO -- only PIC628

port_a_direction = 0b1111_1111 -- all input
port_b_direction = 0b0000_0000 -- all output
	 
port_b = 0b0000_0000	 




var volatile bit b_step is pin_a0
var volatile bit b_dir is pin_a1
var volatile bit a_step is pin_a2
var volatile bit a_dir is pin_a3
var volatile bit step_type is pin_a4


var byte stepper_a    = 0b_0001               -- start of the stepper sequences 
var byte stepper_b    = 0b_0001 

var bit b_step_t = false
var bit a_step_t = false

forever loop


if b_step != b_step_t then -- has the step input changed ?
	 b_step_t = b_step
	 if b_step == false then -- is it the negative going edge?
	 		if b_dir == true then -- what direction should the stepper spin?
	 			 if step_type == true then -- is it full or half step?
	 			 		stepper_motor_half_forward( stepper_b ) -- half foreward
	 			 		port_b_high = stepper_b
	 	  	 else 
	 	  	 		stepper_motor_full_forward( stepper_b ) -- full foreward
	 			 		port_b_high = stepper_b 
	 		   end if
	 		else   
	 		   if step_type == true then
	 			 		stepper_motor_half_backward( stepper_b ) -- half backward
	 			 		port_b_high = stepper_b
	 	  	 else 
	 	  	 		stepper_motor_full_backward( stepper_b ) -- full backward
	 			 		port_b_high = stepper_b 
	 		   end if
	 		end if
	 end if
end if
	 		
	 		
if a_step != a_step_t then -- has the step input changed ?
	 a_step_t = a_step
	 if a_step == false then -- is it the negative going edge?
	 		if a_dir == true then -- what direction should the stepper spin?
	 			 if step_type == true then -- is it full or half step?
	 			 		stepper_motor_half_forward( stepper_a ) -- half foreward
	 			 		port_b_low = stepper_a
	 	  	 else 
	 	  	 		stepper_motor_full_forward( stepper_a ) -- full foreward
	 			 		port_b_low = stepper_a 
	 		   end if
	 		else   
	 		   if step_type == true then
	 			 		stepper_motor_half_backward( stepper_a ) -- half backward
	 			 		port_b_low = stepper_a
	 	  	 else 
	 	  	 		stepper_motor_full_backward( stepper_a ) -- full backward
	 			 		port_b_low = stepper_a 
	 		   end if
	 		end if
	 end if
end if	 		

-- stepper_motor_full_forward( stepper_b )
-- port_b_low = stepper_b
-- port_b_high = stepper_b
-- delay_100ms(1)


end loop