#include "stm32f103xb.h"
#include <stdint.h>

void delay_us(uint16_t us);
void delay_ms(uint16_t ms);

void GPIO_Config(void);
void LCD_Init(void);
void LCD_Send(uint8_t value, uint8_t rs);
void LCD_Print(char *str);
void LCD_Clear(void);
void LCD_SetCursor(uint8_t row, uint8_t col);

void mostrar_menu(uint8_t cursor, uint8_t motor_status, uint8_t motor_dir);
void actualizar_salidas(uint8_t motor_status, uint8_t motor_dir);

int main(void)
{
    uint8_t cursor = 0;        
    uint8_t motor_status = 0;  
    uint8_t motor_dir = 0;     

    GPIO_Config();
    LCD_Init();

    mostrar_menu(cursor, motor_status, motor_dir);
    actualizar_salidas(motor_status, motor_dir);

    while(1)
    {
        
        if((GPIOB->IDR & (1 << 0)) == 0)
        {
            delay_ms(10);
            while((GPIOB->IDR & (1 << 0)) == 0);
            delay_ms(10);

            cursor++;
            if(cursor > 1)
                cursor = 0;

            mostrar_menu(cursor, motor_status, motor_dir);
        }

        if((GPIOB->IDR & (1 << 1)) == 0)
        {
            delay_ms(10);
            while((GPIOB->IDR & (1 << 1)) == 0);
            delay_ms(10);

            if(cursor == 0)
            {
                motor_status = !motor_status;
            }
            else
            {
                motor_dir = !motor_dir;
            }

            actualizar_salidas(motor_status, motor_dir);
            mostrar_menu(cursor, motor_status, motor_dir);
        }
    }
}

void GPIO_Config(void)
{
    RCC->APB2ENR |= RCC_APB2ENR_IOPAEN;
    RCC->APB2ENR |= RCC_APB2ENR_IOPBEN;
    RCC->APB2ENR |= RCC_APB2ENR_AFIOEN;

    
    GPIOA->CRL = 0x22222222;

    
    GPIOA->CRH &= ~(0xFFF);
    GPIOA->CRH |=  (0x222);


    GPIOB->CRL &= ~(0xFF);
    GPIOB->CRL |=  (0x88);
    GPIOB->ODR |=  (1 << 0);
    GPIOB->ODR |=  (1 << 1);

    
    GPIOB->CRH &= ~((0xF << 8) | (0xF << 12));
    GPIOB->CRH |=  ((0x2 << 8) | (0x2 << 12));
}

void LCD_Init(void)
{
    delay_ms(20);

    LCD_Send(0x38, 0);
    delay_ms(5);

    LCD_Send(0x38, 0);
    delay_us(150);

    LCD_Send(0x38, 0);
    delay_us(150);

    LCD_Send(0x38, 0);   
    LCD_Send(0x0C, 0);   
    LCD_Send(0x06, 0);   
    LCD_Send(0x01, 0);   
    delay_ms(2);
}

void LCD_Send(uint8_t value, uint8_t rs)
{
    if(rs)
        GPIOA->BSRR = (1 << 8);  
    else
        GPIOA->BRR  = (1 << 8);   
    GPIOA->BRR = (1 << 9);        

    GPIOA->ODR &= ~(0x00FF);
    GPIOA->ODR |= value;

    GPIOA->BSRR = (1 << 10);      
    delay_us(2);
    GPIOA->BRR  = (1 << 10);      
    delay_us(100);
}

void LCD_Print(char *str)
{
    while(*str)
    {
        LCD_Send(*str, 1);
        str++;
    }
}

void LCD_Clear(void)
{
    LCD_Send(0x01, 0);
    delay_ms(2);
}

void LCD_SetCursor(uint8_t row, uint8_t col)
{
    uint8_t address;

    if(row == 0)
        address = 0x80 + col;
    else
        address = 0xC0 + col;

    LCD_Send(address, 0);
}

void mostrar_menu(uint8_t cursor, uint8_t motor_status, uint8_t motor_dir)
{
    LCD_Clear();

    LCD_SetCursor(0, 0);
    if(cursor == 0)
        LCD_Print(">");
    else
        LCD_Print(" ");

    LCD_Print("Status:");
    if(motor_status)
        LCD_Print("Run ");
    else
        LCD_Print("Stop");

    LCD_SetCursor(1, 0);
    if(cursor == 1)
        LCD_Print(">");
    else
        LCD_Print(" ");

    LCD_Print("Dir:");
    if(motor_dir)
        LCD_Print("Right");
    else
        LCD_Print("Left ");
}

void actualizar_salidas(uint8_t motor_status, uint8_t motor_dir)
{
    if(motor_status)
        GPIOB->BSRR = (1 << 10);
    else
        GPIOB->BRR  = (1 << 10);

    if(motor_dir)
        GPIOB->BSRR = (1 << 11);
    else
        GPIOB->BRR  = (1 << 11);
}

void delay_us(uint16_t us)
{
    volatile uint32_t i;
    while(us--)
    {
        for(i = 0; i < 8; i++);
    }
}

void delay_ms(uint16_t ms)
{
    volatile uint32_t i;
    while(ms--)
    {
        for(i = 0; i < 2000; i++);
    }
}