自己做的板子，写的DAC输出程序，用的是STM32F103C8T6，很简单的程序，PA4和PA5就是无法输出，但是可以置0和1。
        RCC_APB1PeriphClockCmd(RCC_APB1Periph_DAC, ENABLE);
        RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);

void GPIO_Configuration(void)
{
        GPIO_InitTypeDef GPIO_InitStructure;
       
        /* Configure DAC channe1 and DAC channel2 outputs pins */
          GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_4 | GPIO_Pin_5;
        GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
          GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;
          GPIO_Init(GPIOA, &GPIO_InitStructure);                       
}

void dac_config(void)
{
        DAC_InitTypeDef            DAC_InitStructure;

        DAC_InitStructure.DAC_Trigger = DAC_Trigger_None;                //
   // DAC_InitStructure.DAC_WaveGeneration = DAC_WaveGeneration_Noise;          //
    DAC_InitStructure.DAC_WaveGeneration = DAC_WaveGeneration_None;
//        DAC_InitStructure.DAC_LFSRUnmask_TriangleAmplitude = DAC_LFSRUnmask_Bits8_0; //
DAC_InitStructure.DAC_LFSRUnmask_TriangleAmplitude = DAC_LFSRUnmask_Bit0;
   DAC_InitStructure.DAC_OutputBuffer = DAC_OutputBuffer_Disable;                   /
      //DAC_InitStructure.DAC_OutputBuffer = DAC_OutputBuffer_Enable ;
    DAC_Init(DAC_Channel_1, &DAC_InitStructure);
//        DAC_DMACmd(DAC_Channel_1, DISABLE);

       
        DAC_Cmd(DAC_Channel_1, ENABLE);
}

这个程序在原子哥的开发板上就能用，求帮忙！