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今天無(wú)意之間看到了這篇帖子,是斑竹好久前發(fā)的~~~
我突然意識(shí)到我的數(shù)據(jù)好像一直沒(méi)有錯(cuò)位,看到這個(gè)我又試驗(yàn)了一下,發(fā)現(xiàn)把DMA_Cmd(DMA1_Channel1,ENABLE);放置到哪兒都是一樣的啊~~~
這個(gè)是原帖部分:
STM32的AD用DMA方式時(shí)的請(qǐng)注意初始化順序
珍情歲月(84848098) 17:19:23
DMA_DeInit(DMA1_Channel1);
DMA_InitStructure.DMA_PeripheralBaseAddr= ADC1_DR_Address;
DMA_InitStructure.DMA_MemoryBaseAddr= (u32)&ADC_Result;
DMA_InitStructure.DMA_DIR =DMA_DIR_PeripheralSRC;
DMA_InitStructure.DMA_BufferSize= 6;
DMA_InitStructure.DMA_PeripheralInc= DMA_PeripheralInc_Disable;
DMA_InitStructure.DMA_MemoryInc= DMA_MemoryInc_Enable;;
DMA_InitStructure.DMA_PeripheralDataSize= DMA_PeripheralDataSize_HalfWord;
DMA_InitStructure.DMA_MemoryDataSize= DMA_MemoryDataSize_HalfWord;
DMA_InitStructure.DMA_Mode =DMA_Mode_Circular;
DMA_InitStructure.DMA_Priority= DMA_Priority_High;
DMA_InitStructure.DMA_M2M =DMA_M2M_Disable;
DMA_Init(DMA1_Channel1,&DMA_InitStructure);
//DMA_Cmd(DMA1_Channel1,ENABLE);//以前在這里啟用DMA,出現(xiàn)通道錯(cuò)亂
ADC_InitStructure.ADC_Mode =ADC_Mode_Independent;
ADC_InitStructure.ADC_ScanConvMode= ENABLE;
ADC_InitStructure.ADC_ContinuousConvMode= ENABLE;
ADC_InitStructure.ADC_ExternalTrigConv= ADC_ExternalTrigConv_None;
ADC_InitStructure.ADC_DataAlign= ADC_DataAlign_Right;
ADC_InitStructure.ADC_NbrOfChannel= 6;
ADC_Init(ADC1,&ADC_InitStructure);
ADC_RegularChannelConfig(ADC1,ADC_Channel_10, 1, ADC_SampleTime_55Cycles5);
ADC_RegularChannelConfig(ADC1,ADC_Channel_11, 2, ADC_SampleTime_55Cycles5);
ADC_RegularChannelConfig(ADC1,ADC_Channel_12, 3, ADC_SampleTime_55Cycles5);
ADC_RegularChannelConfig(ADC1,ADC_Channel_13, 4, ADC_SampleTime_55Cycles5);
ADC_RegularChannelConfig(ADC1,ADC_Channel_14, 6, ADC_SampleTime_55Cycles5);
ADC_RegularChannelConfig(ADC1,ADC_Channel_15, 5, ADC_SampleTime_55Cycles5);
ADC_DMACmd(ADC1, ENABLE);
ADC_Cmd(ADC1, ENABLE);
ADC_ResetCalibration(ADC1);
while(ADC_GetResetCalibrationStatus(ADC1));
ADC_StartCalibration(ADC1);
while(ADC_GetCalibrationStatus(ADC1));
DMA_Cmd(DMA1_Channel1,ENABLE);
ADC_SoftwareStartConvCmd(ADC1,ENABLE);
以上代碼轉(zhuǎn)自STM32交流群的“情歲月”(84848098) 17:27:48的發(fā)言,在此對(duì)他表示感謝。
下面的經(jīng)驗(yàn)也是“珍情歲月”提供:
用DMA連續(xù)采樣多路,自動(dòng)觸發(fā),如果在初始化AD前使能了DMA就會(huì)出現(xiàn)數(shù)據(jù)錯(cuò)位現(xiàn)象。
要注意在初始化時(shí)將DMA_Cmd(DMA1_Channel1,ENABLE);放置到ADC_SoftwareStartConvCmd(ADC1, ENABLE);前面。
原因是:如果在初始化AD的時(shí)候DMA被觸發(fā)了一次,但是此時(shí)并沒(méi)有采樣,但是DMA目的地址已經(jīng)發(fā)生了自加,
當(dāng)你采樣第一路的時(shí)候,數(shù)據(jù)卻填充到了第二路。
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