F303硬件SPI驱动XPT2046读取数据为0，请教各位大神

只看该作者 · 2015-12-27 12:27

读取数据全为0，折腾了两天了，麻烦各位大神帮忙看看，万分感谢

void Touch_Init(void)
{
      NVIC_InitTypeDef NVIC_InitStructure;
      GPIO_InitTypeDef GPIO_InitStructure;
      EXTI_InitTypeDef EXTI_InitStructure;
      SPI_InitTypeDef SPI_InitStructure;

      RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOC , ENABLE);
      RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI3, ENABLE);
      RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG, ENABLE);

      GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8;//ÉÏÀÍìÍÆÊä³ö
      GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;
      GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
      GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
      GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
      GPIO_Init(GPIOC, &GPIO_InitStructure);

      GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9|GPIO_Pin_11|GPIO_Pin_12|GPIO_Pin_10;
      GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF ;
      GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_DOWN;
      GPIO_Init(GPIOC, &GPIO_InitStructure);

      SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOC, EXTI_PinSource9);
      EXTI_InitStructure.EXTI_Line = EXTI_Line9;
      EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
      EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
      EXTI_InitStructure.EXTI_LineCmd = ENABLE;
      EXTI_Init(&EXTI_InitStructure);

      GPIO_PinAFConfig (GPIOC, GPIO_Pin_11|GPIO_Pin_12|GPIO_Pin_10, GPIO_AF_6);
      SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_256;
      SPI_InitStructure.SPI_CPHA = SPI_CPHA_1Edge ;
      SPI_InitStructure.SPI_CPOL = SPI_CPOL_Low;
      SPI_InitStructure.SPI_CRCPolynomial = 7;
      SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;
      SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
      SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
      SPI_InitStructure.SPI_Mode = SPI_Mode_Master;
      SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;
      SPI_Init(SPI3,&SPI_InitStructure);
      SPI_Cmd(SPI3, ENABLE);

      NVIC_InitStructure.NVIC_IRQChannel = EXTI9_5_IRQn;
      NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;
      NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
      NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
      NVIC_Init(&NVIC_InitStructure);

}

u16 Read_AD(u8 CMD)
{
      u16 num=0,num1=0;
      TCS_ON;
      delay_us(10);
      //while (SPI_I2S_GetFlagStatus(SPI3, SPI_I2S_FLAG_TXE) == RESET);
      SPI_SendData8(SPI3,CMD);//·¢ËÍÃüÁî×Ö
      delay_us(10);
      //while (SPI_I2S_GetFlagStatus(SPI3, SPI_I2S_FLAG_RXNE) == RESET);
      num=SPI_ReceiveData8(SPI3);
      num1=SPI_ReceiveData8(SPI3);
      TCS_OFF;
      num<<=8;
      num|=num1;
      num>>=3;
      num&=0xfff;
      return(num);
}

只看该作者 · 2015-12-27 19:38

用示波器查一下是不是SPI时序的问题