使用STM32F103实现定时器触发ADC采样和DMA传输

实现ADC多通道采样，采用DMA传输，采样由定时器触发

初始化代码：

void  Adc_Init(void)
{ 		
	GPIO_InitTypeDef GPIO_InitStructure;
	DMA_InitTypeDef DMA_InitStructure;
	ADC_InitTypeDef ADC_InitStructure;	
	TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
	TIM_OCInitTypeDef TIM_OCInitStructure;
	
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA |RCC_APB2Periph_ADC1, ENABLE );
	
	// IO口
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;	
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;//ADC0
	GPIO_Init(GPIOA, &GPIO_InitStructure);

	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;	
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1;//ADC1
	GPIO_Init(GPIOA, &GPIO_InitStructure);	
	
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;	
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2;//ADC2
	GPIO_Init(GPIOA, &GPIO_InitStructure);	
	
	// IO口
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;	
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3;//ADC3
	GPIO_Init(GPIOA, &GPIO_InitStructure);	
	
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;	
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4;//ADC4
	GPIO_Init(GPIOA, &GPIO_InitStructure);	
	
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;	
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5;//ADC5
	GPIO_Init(GPIOA, &GPIO_InitStructure);	
	
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AIN;	
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6;//ADC6
	GPIO_Init(GPIOA, &GPIO_InitStructure);		
	
	RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);	
	DMA_DeInit(DMA1_Channel1);
	
	DMA_InitStructure.DMA_PeripheralBaseAddr = ADC1_DR_Address; // ADC地址
	DMA_InitStructure.DMA_MemoryBaseAddr = (u32) &ADC_ConvertedValue;  // 内存地址
	DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralSRC;
	DMA_InitStructure.DMA_BufferSize = 448;
	DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable; // 外设地址固定
	DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable; // 内存地址改变
	DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord; 
	DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord; 
	DMA_InitStructure.DMA_Mode = DMA_Mode_Circular; // 循环
	DMA_InitStructure.DMA_Priority = DMA_Priority_High;
	DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
	DMA_Init(DMA1_Channel1, &DMA_InitStructure);

	DMA_ClearITPendingBit(DMA1_IT_TC1);
	DMA_ITConfig(DMA1_Channel1, DMA_IT_TC, ENABLE); // 允许传输完成中断
	
	DMA_Cmd(DMA1_Channel1,ENABLE);

	ADC_DeInit(ADC1);  //¸´Î»ADC1 
	ADC_InitStructure.ADC_Mode = ADC_Mode_Independent;	// 独立模式
	ADC_InitStructure.ADC_ScanConvMode = ENABLE;	// 多通道扫描
	ADC_InitStructure.ADC_ContinuousConvMode = DISABLE;	// 不使能连续
	ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_T2_CC2; // ADC触发事件
	ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;	// 右对齐
	ADC_InitStructure.ADC_NbrOfChannel = 7;	// 扫描通道数量
	ADC_Init(ADC1, &ADC_InitStructure);
//	ADC_TempSensorVrefintCmd(ENABLE); // 内部温度传感器

	RCC_ADCCLKConfig(RCC_PCLK2_Div6);   // ADC时钟分频

	ADC_RegularChannelConfig(ADC1, ADC_Channel_0, 1, ADC_SampleTime_7Cycles5);
	ADC_RegularChannelConfig(ADC1, ADC_Channel_1, 2, ADC_SampleTime_7Cycles5);
	ADC_RegularChannelConfig(ADC1, ADC_Channel_2, 3, ADC_SampleTime_7Cycles5);
	ADC_RegularChannelConfig(ADC1, ADC_Channel_3, 4, ADC_SampleTime_7Cycles5);
	ADC_RegularChannelConfig(ADC1, ADC_Channel_4, 5, ADC_SampleTime_7Cycles5);
	ADC_RegularChannelConfig(ADC1, ADC_Channel_5, 6, ADC_SampleTime_7Cycles5);
	ADC_RegularChannelConfig(ADC1, ADC_Channel_6, 7, ADC_SampleTime_7Cycles5);

	ADC_DMACmd(ADC1, ENABLE); // 使用DMA模式

	ADC_Cmd(ADC1, ENABLE);	// 使能ADC

	// ADC校准
	ADC_ResetCalibration(ADC1);
	while(ADC_GetResetCalibrationStatus(ADC1));
	ADC_StartCalibration(ADC1);
	while(ADC_GetCalibrationStatus(ADC1));

	ADC_ExternalTrigConvCmd(ADC1, ENABLE);		// 使能外部事件触发	
	
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
	
	TIM_TimeBaseStructure.TIM_Period = 255;
	TIM_TimeBaseStructure.TIM_Prescaler = 99; // 频率3.2kHz
	TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
	TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
	TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
	
	TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
	TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
	TIM_OCInitStructure.TIM_Pulse = 1000;
	TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;
	TIM_OC2Init(TIM2, &TIM_OCInitStructure);
	
	TIM_Cmd(TIM2, ENABLE);	
}