ADC-定时器触发

定时器触发：通过定时器产生外部触发信号的方式叫做定时器触发

试验：光敏传感器的模拟输出接到PA0引脚上，PA0对应的是单片机ADC的通道0，把通道0写入到注入序列第一行，外部触发信号选择TIM1_TRGO，通过定时器1的TRGO产生脉冲启动注入序列，注入序列第一行被执行完，通道0的转换结果被保存到JDR1寄存器，把JDR1寄存器里存储的结果读出来。

1.连接电路

2.初始化串口

3.配置定时器1的TRGO

4.注入序列的编程接口

5.初始化ADC(注入序列)

6.读取并发送测量结果

cs 复制代码

	while(1)
	{
		//1.等待注入序列转换完成
		while(ADC_GetFlagStatus(ADC1, ADC_FLAG_JEOC)== RESET);
		
		//2.读取转换的结果
		uint16_t jdrl = ADC_GetInjectedConversionValue (ADC1, ADC_InjectedChannel_1);
		
		//3.清除JEoc标志位
		ADC_ClearFlag (ADC1, ADC_FLAG_JEOC) ;
		
		//4.把结果转换成电压
		float voltage = jdrl * (3.3f / 4095);
		
		//#5.通过串口把结果发送出发去
		My_USART_Printf (USART1, "%.3f\n", voltage);
	}

总代码：

cs 复制代码

#include "stm32f10x.h"
#include "usart.h"

void App_USART1_Init(void);
void App_TIM1_Init(void);
void App_ADC_Init(void);

int main(void)
{
	App_USART1_Init();
	App_TIM1_Init();
	App_ADC_Init();
	
//	My_USART_SendString(USART1, "Hello world. \r\n");

	
	while(1)
	{
		//1.等待注入序列转换完成
		while(ADC_GetFlagStatus(ADC1, ADC_FLAG_JEOC)== RESET);
		
		//2.读取转换的结果
		uint16_t jdrl = ADC_GetInjectedConversionValue (ADC1, ADC_InjectedChannel_1);
		
		//3.清除JEoc标志位
		ADC_ClearFlag (ADC1, ADC_FLAG_JEOC) ;
		
		//4.把结果转换成电压
		float voltage = jdrl * (3.3f / 4095);
		
		//#5.通过串口把结果发送出发去
		My_USART_Printf (USART1, "%.3f\n", voltage);
	}
}

void App_USART1_Init(void)
{
	//#1.初始化I0引脚，A9
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE);
	GPIO_InitTypeDef GPIO_InitStruct = {0};
	GPIO_InitStruct.GPIO_Pin = GPIO_Pin_9;
	GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF_PP;
	GPIO_InitStruct.GPIO_Speed = GPIO_Speed_2MHz;
	GPIO_Init(GPIOA, &GPIO_InitStruct);
	
	//#2.开启USART1的时钟
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);
	
	//#3.配置串口的参数
	USART_InitTypeDef USART_InitStruct = {0};

	USART_InitStruct.USART_BaudRate = 115200;
	USART_InitStruct.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
	USART_InitStruct.USART_Mode = USART_Mode_Tx;
	USART_InitStruct.USART_Parity = USART_Parity_No;
	USART_InitStruct.USART_StopBits = USART_StopBits_1;
	USART_InitStruct.USART_WordLength = USART_WordLength_8b;
	USART_Init(USART1, &USART_InitStruct);
	
	//#4.闭合串口的总开关
	USART_Cmd(USART1, ENABLE);
}

void App_TIM1_Init(void)
{
	//#1.使能TIM1的时钟
	RCC_APB2PeriphClockCmd (RCC_APB2Periph_TIM1,ENABLE);
	//#2.配置TIM1的时基单元
	TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStruct = {0};
	TIM_TimeBaseInitStruct.TIM_CounterMode = TIM_CounterMode_Up;
	TIM_TimeBaseInitStruct.TIM_Period = 999;
	TIM_TimeBaseInitStruct.TIM_Prescaler = 71;
	TIM_TimeBaseInitStruct.TIM_RepetitionCounter = 0;
	TIM_TimeBaseInit (TIM1, &TIM_TimeBaseInitStruct);
	
	// #3. TRGO:Update
	TIM_SelectOutputTrigger (TIM1,TIM_TRGOSource_Update);
	
	//#4.开启定时器1的总开关
	TIM_Cmd(TIM1, ENABLE);
}

void App_ADC_Init(void)
{
	//#1.初始化I0引脚
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE) ;
	GPIO_InitTypeDef GPIO_InitStruct = {0};
	GPIO_InitStruct.GPIO_Pin = GPIO_Pin_0;
	GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AIN;
	GPIO_Init (GPIOA, &GPIO_InitStruct) ;
	
	//#2.配置ADC模块的时钟
	RCC_ADCCLKConfig (RCC_PCLK2_Div6);
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);
	
	//#3.配置ADC的基本参数
	ADC_InitTypeDef ADC_InitStruct = {0};
	ADC_InitStruct.ADC_ContinuousConvMode = DISABLE;
	ADC_InitStruct.ADC_DataAlign = ADC_DataAlign_Right;
	ADC_InitStruct.ADC_ExternalTrigConv = ADC_ExternalTrigConv_None;
	ADC_InitStruct.ADC_Mode = ADC_Mode_Independent;
	ADC_InitStruct.ADC_NbrOfChannel = 1;
	ADC_InitStruct.ADC_ScanConvMode = DISABLE;
	ADC_Init (ADC1,&ADC_InitStruct);
	
	//#4.配置注入序列的额外参数
	ADC_InjectedSequencerLengthConfig(ADC1,1);
	ADC_ExternalTrigInjectedConvConfig(ADC1, ADC_ExternalTrigInjecConv_T1_TRGO);
	ADC_ExternalTrigInjectedConvCmd(ADC1,ENABLE);
	ADC_InjectedChannelConfig(ADC1,ADC_Channel_0, 1, ADC_SampleTime_13Cycles5);
	
	//#5.闭合总开关
	ADC_Cmd(ADC1,ENABLE);
}