[STM32F0] STM32F072使用ADC产生伪随机数

<p>#include "adc_random.h"



uint16_t Get_ADC_RandomSeek(void);</p><p>

/*初始化ADC*/

void ADC_RandomConfig(void)

{

 ADC_InitTypeDef ADC_InitStructure;

 GPIO_InitTypeDef GPIO_InitStructure;



 RCC_AHBPeriphClockCmd(ADC_RANDOM_GPIO_CLK, ENABLE);

 RCC_APB2PeriphClockCmd(ADC_RANDOM_CLK, ENABLE);



 GPIO_InitStructure.GPIO_Pin = ADC_RANDOM_PIN;

 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AN;

 GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_NOPULL ;

 GPIO_Init(ADC_RANDOM_GPIO_PORT, &GPIO_InitStructure);



 ADC_DeInit(ADC_RANDOM);

 ADC_StructInit(&ADC_InitStructure);



 ADC_InitStructure.ADC_Resolution = ADC_Resolution_12b;

 ADC_InitStructure.ADC_ContinuousConvMode = ENABLE; 

 ADC_InitStructure.ADC_ExternalTrigConvEdge = ADC_ExternalTrigConvEdge_None;

 ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;

 ADC_InitStructure.ADC_ScanDirection = ADC_ScanDirection_Upward;

 ADC_Init(ADC_RANDOM, &ADC_InitStructure); 

 ADC_ChannelConfig(ADC_RANDOM, ADC_RANDOM_CHANNEL , ADC_SampleTime_1_5Cycles);

 ADC_GetCalibrationFactor(ADC_RANDOM);

 ADC_Cmd(ADC_RANDOM, ENABLE); 

 while(!ADC_GetFlagStatus(ADC_RANDOM, ADC_FLAG_ADRDY)); 

}



/采集4次ADC的值，每次取采集的第四位，拼成16位作为种子*/

uint16_t Get_ADC_RandomSeek(void)

{

 uint8_t Count;

 uint16_t ADC_RandomSeek = 0;

 ADC_StartOfConversion(ADC_RANDOM);

 for(Count = 0; Count < 4; Count++){

 while(ADC_GetFlagStatus(ADC_RANDOM, ADC_FLAG_EOC) == RESET){

 ;

 }

 ADC_RandomSeek <<= 4;

 ADC_RandomSeek += ADC_GetConversionValue(ADC_RANDOM) & 0x000f;

 }

 ADC_StopOfConversion(ADC_RANDOM);

 return ADC_RandomSeek;

}



/*拿种子产生随机数*/

uint16_t Get_ADC_Random(void)

{

 srand(Get_ADC_RandomSeek());

 return rand();

}

</p>

int main(void)

{

  uint16_t RandomNumber, RandomSeek;



  USART2_GPIO_Init();

        

  ADC_RandomConfig();

  

  while (1)

  {

    RandomSeek = Get_ADC_Random();

    srand(RandomSeek);

    RandomNumber = rand();

    printf("RandomSeek = %d\t\tRandomNumber = %d\n", RandomSeek, RandomNumber);

    delay_ms(500);

  }

}