// Will Patrick 
//
// Adapted from:
//
// hello.arduino.328P.blink.c
//
// test blinking LED
//
// Neil Gershenfeld
// 10/21/13
//

#include <avr/io.h>
#include <util/delay.h>

#define output(directions,pin) (directions |= pin) // set port direction for output
#define set(port,pin) (port |= pin) // set port pin
#define clear(port,pin) (port &= (~pin)) // clear port pin
#define pin_test(pins,pin) (pins & pin) // test for port pin
#define bit_test(byte,bit) (byte & (1 << bit)) // test for bit set

#define portb PORTB // H-bridge port
#define portd PORTD // H-bridge port

// Stepper 1

#define bridge_direction_b DDRB // H-bridge direction
#define bridge_direction_d DDRD // H-bridge direction
#define S1_A_IN2 (1 << PB2) // H-bridge output pins
#define S1_A_IN1 (1 << PB1) // "
#define S1_B_IN2 (1 << PB0) // "
#define S1_B_IN1 (1 << PD7) // "

// Stepper 2

// Solenoid

#define sol_gate (1 << PD4) //
#define sol_port PORTD // Port used for solenoid


#define on_delay() _delay_us(25) // PWM on time
#define off_delay() _delay_us(5) // PWM off time
#define PWM_count 100 // number of PWM cycles
#define step_count 20 // number of steps

static uint8_t count;

//
// A+ B+ PWM pulse
//
void pulse_ApBp() {
  clear(portb, S1_A_IN2);
  clear(portb, S1_B_IN2);
  set(portb, S1_A_IN1);
  set(portd, S1_B_IN1);
   for (count = 0; count < PWM_count; ++count) {
      set(portb, S1_A_IN1);
      set(portd, S1_B_IN1);
      on_delay();
      clear(portb, S1_A_IN1);
      clear(portd, S1_B_IN1);
      off_delay();
      }
   }
//
// A+ B- PWM pulse
//
void pulse_ApBm() {
  clear(portb, S1_A_IN2);
  clear(portd, S1_B_IN1);
  set(portb, S1_A_IN1);
  set(portb, S1_B_IN2);
   for (count = 0; count < PWM_count; ++count) {
      set(portb, S1_A_IN1);
      set(portb, S1_B_IN2);
      on_delay();
      clear(portb, S1_A_IN1);
      clear(portb, S1_B_IN2);
      off_delay();
      }
   }
//
// A- B+ PWM pulse
//
void pulse_AmBp() {
  clear(portb, S1_A_IN1);
  clear(portb, S1_B_IN2);
  set(portb, S1_A_IN2);
  set(portd, S1_B_IN1);
   for (count = 0; count < PWM_count; ++count) {
      set(portb, S1_A_IN2);
      set(portd, S1_B_IN1);
      on_delay();
      clear(portb, S1_A_IN2);
      clear(portd, S1_B_IN1);
      off_delay();
      }
   }
//
// A- B- PWM pulse
//
void pulse_AmBm() {
  clear(portb, S1_A_IN1);
  clear(portd, S1_B_IN1);
  set(portb, S1_A_IN2);
  set(portb, S1_B_IN2);
   for (count = 0; count < PWM_count; ++count) {
      set(portb, S1_A_IN2);
      set(portb, S1_B_IN2);
      on_delay();
      clear(portb, S1_A_IN2);
      clear(portb, S1_B_IN2);
      off_delay();
      }
   }
//
// clockwise step
//
void step_cw() {
   pulse_ApBp();
   pulse_AmBp();
   pulse_AmBm();
   pulse_ApBm();
   }
//
// counter-clockwise step
//
void step_ccw() {
   pulse_ApBm();
   pulse_AmBm();
   pulse_AmBp();
   pulse_ApBp();
   }

int main(void) {
   //
   // main
   //
   static uint8_t i,j;
   //
   // set clock divider to /1
   //
   CLKPR = (1 << CLKPCE);
   CLKPR = (0 << CLKPS3) | (0 << CLKPS2) | (0 << CLKPS1) | (0 << CLKPS0);
   //
   // initialize bridge pins
   //
   clear(portb, S1_A_IN1);
   output(bridge_direction_b, S1_A_IN1);
   clear(portb, S1_A_IN2);
   output(bridge_direction_b, S1_A_IN2);
   clear(portd, S1_B_IN1);
   output(bridge_direction_d, S1_B_IN1);
   clear(portb, S1_B_IN2);
   output(bridge_direction_b, S1_B_IN2);
   //
   // main loop
   //
   while (1) {
      for (i = 0; i < step_count; ++i) {
         for (j = 0; j < i; ++j)
            step_cw();
            set(sol_port, sol_gate);
         for (j = 0; j < i; ++j)
            step_ccw();
            clear(sol_port,sol_gate);
         


         }
      for (i = step_count; i > 0; --i) {
         for (j = 0; j < i; ++j)
            step_cw();
         set(sol_port, sol_gate);
         for (j = 0; j < i; ++j)
            step_ccw();
         clear(sol_port,sol_gate);
         }
      }
   }