Stm32f103 DAC 學習筆記
最近在做電流型信號輸出的項目，遇到了些問題這里把這些解決方法做一個筆記方便以后運用。在搞這個的時候因為手冊這部分講的不是很詳細，所以在使用上也遇到了些阻力。
用的是64封裝的芯， 此芯ADC的基准Vref+和電源是同一個端口，Vref-共用電源地。在電池輸出時AD值為0時 取樣電阻100歐姆 有0.66mA的電流輸出，只要在初始化時只要失能端口輸出緩沖，輸出可到0.0025mA。OK問題就解決了。
1 void AnalogInit(void) 2 { 3 DAC_InitTypeDef DAC_InitStructure; 4 GPIO_InitTypeDef GPIO_InitStructure; 5 6 RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO | RCC_APB2Periph_GPIOA, ENABLE); 7 /* DAC Periph clock enable */ 8 RCC_APB1PeriphClockCmd(RCC_APB1Periph_DAC, ENABLE); 9 10 /* Configure DAC channe1 output pin */ 11 GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4; 12 GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; 13 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP; 14 GPIO_Init(GPIOA, &GPIO_InitStructure); 15 16 /* Configure DAC channe1 output pin */ 17 GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5; 18 GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; 19 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP; 20 GPIO_Init(GPIOA, &GPIO_InitStructure); 21 22 23 /* DAC channel1 Configuration */ 24 DAC_InitStructure.DAC_Trigger = DAC_Trigger_Software; 25 DAC_InitStructure.DAC_WaveGeneration = DAC_WaveGeneration_None; 26 DAC_InitStructure.DAC_OutputBuffer = DAC_OutputBuffer_Disable; //輸出緩沖失能 27 DAC_InitStructure.DAC_LFSRUnmask_TriangleAmplitude = DAC_TriangleAmplitude_4095; 28 29 DAC_Init(DAC_Channel_1, &DAC_InitStructure); 30 31 /* DAC channel2 Configuration */ 32 DAC_Init(DAC_Channel_2, &DAC_InitStructure); 33 34 /* Enable DAC Channel1: Once the DAC channel1 is enabled, PA.04 is 35 automatically connected to the DAC converter. */ 36 DAC_Cmd(DAC_Channel_1, ENABLE); 37 /* Enable DAC Channel2: Once the DAC channel2 is enabled, PA.05 is 38 automatically connected to the DAC converter. */ 39 DAC_Cmd(DAC_Channel_2, ENABLE); 40 41 } 42 43 //端口1AD值更新 44 void DAC1_update(u16 ch1) 45 { 46 ch1 = (ch1 <<4) & 0xfff0; 47 /* Set DAC Channel1 DHR12L register */ 48 DAC_SetChannel1Data(DAC_Align_12b_L, ch1); 49 50 /* Start DAC Channel1 conversion by software */ 51 DAC_SoftwareTriggerCmd(DAC_Channel_1, ENABLE); 52 } 53 54 void DAC2_update(u16 ch2) 55 { 56 ch2 = (ch2 <<4) & 0xfff0; 57 /* Set DAC Channel2 DHR12L register */ 58 DAC_SetChannel2Data(DAC_Align_12b_L, ch2); 59 60 /* Start DAC Channel1 conversion by software */ 61 DAC_SoftwareTriggerCmd(DAC_Channel_2, ENABLE); 62 }