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//  28BYJ-48 stepper motor example
//  showing how to control a unipolar stepper motor by mbed digital output ports.
//  Tested on the Nucleo F103RB Board
//  Based on http://www.geeetech.com/wiki/index.php/Stepper_Motor_5V_4-Phase_5-Wire_%26_ULN2003_Driver_Board_for_Arduino
//  Using the ULN2003A Driver.

#include "mbed.h"

BusOut motor_out(PC_0, PC_1, PC_2, PC_3);  // blue - pink - yellow - orange

int step = 0; 
int dir = 1; // direction

int main()
{
    while(1)
    { 
        switch(step)
        { 
            case 0: motor_out = 0x1; break;  // 0001
            case 1: motor_out = 0x3; break;  // 0011
            case 2: motor_out = 0x2; break;  // 0010   
            case 3: motor_out = 0x6; break;  // 0110
            case 4: motor_out = 0x4; break;  // 0100
            case 5: motor_out = 0xC; break;  // 1100
            case 6: motor_out = 0x8; break;  // 1000
            case 7: motor_out = 0x9; break;  // 1001
            
            default: motor_out = 0x0; break; // 0000
        }
  
        if(dir) step++; else step--; 
        if(step>7)step=0; 
        if(step<0)step=7; 
        wait(0.015);  // speed
    }
}