#include <stm32f10x.h>
#include <stm32f10x_rcc.h>
#include <stm32f10x_gpio.h>

static __IO uint32_t TimingDelay;

void Delay(uint32_t nTime)
{
  TimingDelay = nTime;
  while(TimingDelay != 0);
}

void SysTick_Handler(void)
{
  if(TimingDelay != 0)
    TimingDelay--;
}

int main(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;

  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);

  GPIO_StructInit(&GPIO_InitStructure);
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;
  GPIO_Init(GPIOB, &GPIO_InitStructure);

  if(SysTick_Config(SystemCoreClock / 1000))
    while(1);

  while(1)
  {
    static int ledval = 0;

    GPIO_WriteBit(GPIOB, GPIO_Pin_0, (ledval) ? Bit_SET : Bit_RESET);
    ledval = 1 - ledval;

    Delay(250);
  }

  return 0;
}

#ifdef USE_FULL_ASSERT
void assert_failed(uint8_t *file, uint32_t line)
{
  while(1);
}
#endif