1 | uint8_t aa = 0x55; |
变量保存在SRAM中。
1 | const uint8_t bb = 0x66; |
在STM32中,使用const定义的常量,存储在Flash中,如果有一个很大的查找表或者字库之类的,最好加const,保存在Flash中,避免占用SRAM。
1 | OLED_ShowHexNum(1,1,(uint32_t)&ADC1->DR,8); |
外设寄存器的地址,是固定的,在手册中可以查询到。
常用函数
1 | void DMA_DeInit(DMA_Channel_TypeDef* DMAy_Channelx); |
DMA恢复缺省配置
1 | void DMA_Init(DMA_Channel_TypeDef* DMAy_Channelx, DMA_InitTypeDef* DMA_InitStruct); |
DMA初始化
1 | void DMA_StructInit(DMA_InitTypeDef* DMA_InitStruct); |
DMA结构体初始化
1 | void DMA_Cmd(DMA_Channel_TypeDef* DMAy_Channelx, FunctionalState NewState); |
DMA使能
1 | void DMA_ITConfig(DMA_Channel_TypeDef* DMAy_Channelx, uint32_t DMA_IT, FunctionalState NewState); |
DMA中断输出使能
1 | void DMA_SetCurrDataCounter(DMA_Channel_TypeDef* DMAy_Channelx, uint16_t DataNumber); |
DMA设置当前数据寄存器,给传输计数器写数据
1 | uint16_t DMA_GetCurrDataCounter(DMA_Channel_TypeDef* DMAy_Channelx); |
DMA获取当前数据寄存器,返回传输计数器的值,可以查看还有多少数据没有转运。
1 | FlagStatus DMA_GetFlagStatus(uint32_t DMAy_FLAG); |
获取标志位状态
1 | void DMA_ClearFlag(uint32_t DMAy_FLAG); |
清除标志位
1 | ITStatus DMA_GetITStatus(uint32_t DMAy_IT); |
获取中断状态
1 | void DMA_ClearITPendingBit(uint32_t DMAy_IT); |
清除中断挂起位
8-1DMA数据转运
MyDMA.c
1234567891011121314151617181920212223242526272829303132333435 | uint16_t MyDMA_Size; void MyDMA_Init(uint32_t AddrA,uint32_t AddrB,uint16_t size){ MyDMA_Size = size; RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1,ENABLE);//DMA是AHB总线的设备 DMA_InitTypeDef DMA_InitStructure; DMA_InitStructure.DMA_PeripheralBaseAddr = AddrA;//外设站点的起始地址 DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte;//外设站点的数据宽度 DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Enable;//外设站点是否自增 DMA_InitStructure.DMA_MemoryBaseAddr = AddrB;//存储器站点的起始地址 DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte;//存储器站点的数据宽度 DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;//存储器站点是否自增 DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;//传输方向 DMA_InitStructure.DMA_BufferSize = size;//缓冲区大小(传输计数器) DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;//传输模式(是否自动重装) DMA_InitStructure.DMA_M2M = DMA_M2M_Enable;//是否是存储器到存储器(软件触发还是硬件触发) DMA_InitStructure.DMA_Priority = DMA_Priority_VeryHigh;//优先级 DMA_Init(DMA1_Channel1,&DMA_InitStructure); DMA_Cmd(DMA1_Channel1,DISABLE);} void MyDMA_Transfer(void){ DMA_Cmd(DMA1_Channel1,DISABLE);//失能DMA DMA_SetCurrDataCounter(DMA1_Channel1,MyDMA_Size);//设置传输计数器 DMA_Cmd(DMA1_Channel1,ENABLE);//再次使能DMA while(DMA_GetFlagStatus(DMA1_FLAG_TC1) == RESET);//查看转运完成标志位 DMA_ClearFlag(DMA1_FLAG_TC1);} |
main.c
1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253 | uint8_t DataA[] = {0x01, 0x02, 0x03, 0x04};//源端数组uint8_t DataB[] = {0, 0, 0, 0};//目标数组 int main(void){ OLED_Init(); MyDMA_Init((uint32_t)DataA, (uint32_t)DataB, 4);//把2个数组传进去,长度为4 //先展示两个数组的地址 OLED_ShowString(1,1,"DataA"); OLED_ShowString(3,1,"DataB"); OLED_ShowHexNum(1,8,(uint32_t)DataA,8); OLED_ShowHexNum(3,8,(uint32_t)DataB,8); while(1) { //给DataA数组数据自增1 DataA[0]++; DataA[1]++; DataA[2]++; DataA[3]++; //展示2个数组的值 OLED_ShowHexNum(2,1,DataA[0],2); OLED_ShowHexNum(2,4,DataA[1],2); OLED_ShowHexNum(2,7,DataA[2],2); OLED_ShowHexNum(2,10,DataA[3],2); OLED_ShowHexNum(4,1,DataB[0],2); OLED_ShowHexNum(4,4,DataB[1],2); OLED_ShowHexNum(4,7,DataB[2],2); OLED_ShowHexNum(4,10,DataB[3],2); //延时1s,触发DMA转运 Delay_s(1); MyDMA_Transfer(); //展示转运之后的2个数组的值 OLED_ShowHexNum(2,1,DataA[0],2); OLED_ShowHexNum(2,4,DataA[1],2); OLED_ShowHexNum(2,7,DataA[2],2); OLED_ShowHexNum(2,10,DataA[3],2); OLED_ShowHexNum(4,1,DataB[0],2); OLED_ShowHexNum(4,4,DataB[1],2); OLED_ShowHexNum(4,7,DataB[2],2); OLED_ShowHexNum(4,10,DataB[3],2); Delay_s(1); } } |
DMA+AD多通道
AD.c
12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576 | uint16_t ADValue[4]; void AD_Init(void){ RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1,ENABLE);//开启ADC1的时钟,ADC是APB2上的设备 RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE); RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1,ENABLE);//开启DMA时钟 RCC_ADCCLKConfig(RCC_PCLK2_Div6);//配置ADCCLK,分频时钟 GPIO_InitTypeDef GPIO_InitStructure; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;//选择模拟输入模式,是ADC的专属模式 GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_Init(GPIOA, &GPIO_InitStructure); //扫描PA0-PA3一共四个通道 ADC_RegularChannelConfig(ADC1,ADC_Channel_0,1,ADC_SampleTime_55Cycles5);//通道0 ADC_RegularChannelConfig(ADC1,ADC_Channel_1,2,ADC_SampleTime_55Cycles5);//通道1 ADC_RegularChannelConfig(ADC1,ADC_Channel_2,3,ADC_SampleTime_55Cycles5);//通道2 ADC_RegularChannelConfig(ADC1,ADC_Channel_3,4,ADC_SampleTime_55Cycles5);//通道3 //配置ADC ADC_InitTypeDef ADC_InitStructure; ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;//数据对齐,选择右对齐 ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_None;//不使用外部触发,使用软件触发 ADC_InitStructure.ADC_Mode = ADC_Mode_Independent;//ADC工作模式,独立模式 ADC_InitStructure.ADC_ContinuousConvMode = DISABLE;//连续转换模式还是单次转换模式 ADC_InitStructure.ADC_ScanConvMode = ENABLE;//扫描模式写ENABLE ADC_InitStructure.ADC_NbrOfChannel = 4;//扫描模式下的通道数目,4个通道 ADC_Init(ADC1,&ADC_InitStructure); //ADC扫描模式+DMA数据转运 DMA_InitTypeDef DMA_InitStructure; DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&ADC1->DR;//外设基地址,从这里开始,ADC1->DR就是外设基地址 DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;//想要DR寄存器低16位的寄存器,因此数据宽度写半字 DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;//不自增,始终转运一个地址的数据 DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)ADValue;//存储器基地址,保存在数组中 DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;//也是半字 DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;//存储器地址要自增,每转运一次,到下一个 DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;//传输方向 DMA_InitStructure.DMA_BufferSize = 4;//有4个通道,传输4次 DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;//传输模式 DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;//不使用软件触发,使用硬件触发,触发源为ADC1 DMA_InitStructure.DMA_Priority = DMA_Priority_VeryHigh; DMA_Init(DMA1_Channel1,&DMA_InitStructure);//这里通道不能任意选择 DMA_Cmd(DMA1_Channel1,DISABLE); ADC_DMACmd(ADC1,ENABLE);//使能ADC和DMA通道 ADC_Cmd(ADC1,ENABLE); //对ADC进行校准 ADC_ResetCalibration(ADC1);//复位校准 while (ADC_GetResetCalibrationStatus(ADC1) == SET);//返回复位校准状态 ADC_StartCalibration(ADC1);//开始校准 while (ADC_GetCalibrationStatus(ADC1) == SET);//等待校准完成} void AD_GetValue(void){ DMA_Cmd(DMA1_Channel1,DISABLE); DMA_SetCurrDataCounter(DMA1_Channel1,4); DMA_Cmd(DMA1_Channel1,ENABLE); ADC_SoftwareStartConvCmd(ADC1,ENABLE);//软件触发ADC转换 while(DMA_GetFlagStatus(DMA1_FLAG_TC1) == RESET);//等待转运完成 DMA_ClearFlag(DMA1_FLAG_TC1);//恢复标志位} |
main.c
1234567891011121314151617181920212223242526 | uint16_t AD0,AD1,AD2,AD3;int main(void){ OLED_Init(); AD_Init(); OLED_ShowString(1,1,"AD0:"); OLED_ShowString(2,1,"AD1:"); OLED_ShowString(3,1,"AD2:"); OLED_ShowString(4,1,"AD3:"); while(1) { AD_GetValue(); OLED_ShowNum(1,5,ADValue[0],4); OLED_ShowNum(2,5,ADValue[1],4); OLED_ShowNum(3,5,ADValue[2],4); OLED_ShowNum(4,5,ADValue[3],4); Delay_ms(100); }} |