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1、485 最基本的半双工通信配置采用 STM32F103ZET6串口 3 连接 485 芯片通信口，485 芯片的 A,B 通过 485 转串口模块与电脑相连，完成在串口软件上输入输出功能。串口 3，配置函数：void USART3_Config(void)GPIO_InitTypeDef GPIO_InitStructure;USART_InitTypeDef USART_InitStructure;NVIC_InitTypeDef NVIC_InitStructure;RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB|RCC_APB2Periph_AFI
2、O,ENABLE);RCC_APB1PeriphClockCmd(RCC_APB1Periph_USART3,ENABLE);/USART3_TX-PB10,USART3_RX-PB11GPIO_InitStructure.GPIO_Pin=GPIO_Pin_10;GPIO_InitStructure.GPIO_Mode=GPIO_Mode_AF_PP;GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz;GPIO_Init(GPIOB,&GPIO_InitStructure);GPIO_InitStructure.GPIO_Pin=GPIO_Pin_1
3、1;GPIO_InitStructure.GPIO_Mode=GPIO_Mode_IN_FLOATING;GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz;GPIO_Init(GPIOB,&GPIO_InitStructure);USART_InitStructure.USART_BaudRate=115200;/1200;USART_InitStructure.USART_WordLength=USART_WordLength_8b;USART_InitStructure.USART_StopBits=USART_StopBits_1;USART_
4、InitStructure.USART_Parity=USART_Parity_No;/USART_Parity_Even;USART_InitStructure.USART_HardwareFlowControl=USART_HardwareFlowControl_None;USART_InitStructure.USART_Mode=USART_Mode_Rx|USART_Mode_Tx;USART_Init(USART3,&USART_InitStructure);NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2);NVIC_InitStruct
5、ure.NVIC_IRQChannel=USART3_IRQn;NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=1;NVIC_InitStructure.NVIC_IRQChannelSubPriority=0;NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE;NVIC_Init(&NVIC_InitStructure);#ifdef PDU_USART3_DMAUSART_ITConfig(USART3,USART_IT_IDLE,ENABLE);#else/Enable the USART R
6、eceive interrupt:this interrupt is generated when the/USART3 receive data register is not empty/USART_ClearITPendingBit(USART3,USART_IT_TC);USART_ClearFlag(USART3,USART_FLAG_TC);USART_ITConfig(USART3,USART_IT_RXNE,ENABLE);USART_ITConfig(USART3,USART_IT_TC,ENABLE);/USART_ITConfig(USART3,USART_IT_TXE,
7、ENABLE);USART_ClearFlag(USART3,USART_FLAG_TC);#endif USART_Cmd(USART3,ENABLE);USART_ClearFlag(USART3,USART_FLAG_TC);RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOE|RCC_APB2Periph_AFIO,ENABLE);GPIO_InitStructure.GPIO_Pin=GPIO_Pin_15;GPIO_InitStructure.GPIO_Mode=GPIO_Mode_Out_PP;GPIO_InitStructure.GPIO_Sp
8、eed=GPIO_Speed_50MHz;GPIO_Init(GPIOE,&GPIO_InitStructure);RS_485_TX_ENABLE();PUTCHAR_PROTOTYPE/*Place your implementation of fputc here*/*e.g.write a character to the USART*/USART_SendData(USART3,(uint8_t)ch);/USART_SendData(USART1,(uint8_t)ch);/*Loop until the end of transmission*/while(USART_GetFl
9、agStatus(USART1,USART_FLAG_TC)=RESET)while(USART_GetFlagStatus(USART3,USART_FLAG_TXE)=RESET)return ch;中断函数：void USART3_IRQHandler(void)if(USART_GetITStatus(USART3,USART_IT_IDLE)!=RESET)USART_ClearITPendingBit(USART3,USART_IT_IDLE);if(USART_GetFlagStatus(USART3,USART_FLAG_RXNE)!=RESET)USART_ClearFlag
10、(USART3,USART_FLAG_RXNE);TIM3_Init(1000,7200);BLUE_ON();if(cnt=32)cnt=0;elsedatacnt=USART_ReceiveData(USART3);cnt+;if(USART_GetITStatus(USART3,USART_IT_TC)!=RESET)|(USART_GetITStatus(USART3,USART_IT_TXE)!=RESET)USART_ClearITPendingBit(USART3,USART_IT_TC);USART_ClearITPendingBit(USART3,USART_IT_TXE);
11、/USART_SendData(USART3,0XFFFF);void TIM3_IRQHandler(void)if(TIM_GetITStatus(TIM3,TIM_IT_Update)!=RESET)TIM_ClearITPendingBit(TIM3,TIM_IT_Update);TIM3_DeInit();BLUE_OFF();/printf(rn%x,cnt);cnt=0;static void NVIC_TIM3Configuration(void)NVIC_InitTypeDef NVIC_InitStructure;/*Set the Vector Table base ad
12、dress at 0 x08000000*/NVIC_SetVectorTable(NVIC_VectTab_FLASH,0 x0000);/*Enable the TIM3 gloabal Interrupt*/NVIC_InitStructure.NVIC_IRQChannel=TIM3_IRQn;NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=0;NVIC_InitStructure.NVIC_IRQChannelSubPriority=1;NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE;
13、NVIC_Init(&NVIC_InitStructure);定时器：void TIM3_Init(uint16_t tcon,uint16_t psc)TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;/TIM3 clock enableRCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3,ENABLE);/reset timerTIM_DeInit(TIM3);/Time base configuration/value to reloadTIM_TimeBaseStructure.TIM_Period=(tcon-
14、1);/pre-scaler value against system clockTIM_TimeBaseStructure.TIM_Prescaler=(psc-1);/scaler value against system clockTIM_TimeBaseStructure.TIM_ClockDivision=0;/counting modeTIM_TimeBaseStructure.TIM_CounterMode=TIM_CounterMode_Up;/init timerTIM_TimeBaseInit(TIM3,&TIM_TimeBaseStructure);/Clear TIM3
15、 update pending flagTIM_ClearITPendingBit(TIM3,TIM_IT_Update);/TIM IT enable of over-countingTIM_ITConfig(TIM3,TIM_IT_Update,ENABLE);/config timers interruption functionNVIC_TIM3Configuration();/Enable TIM3 counterTIM_Cmd(TIM3,ENABLE);void TIM3_DeInit(void)/Disable TIM3 counterTIM_Cmd(TIM3,DISABLE);
16、/Reset timerTIM_DeInit(TIM3);/Disable TIM3 clockRCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3,DISABLE);/tim3_stat=0 x00;主函数：#ifdef _GNF_#ifdef _GNUC_/*With GCC/RAISONANCE,small printf(option LD Linker-Libraries-Small printfset to Yes)calls _io_putchar()*/#define PUTCHAR_PROTOTYPE int _io_putchar(int ch
17、)#else#define PUTCHAR_PROTOTYPE int fputc(int ch,FILE*f)#endif/*_GNUC_*/#endif/*_GNF_*/void Delay(uint32_t tick)while(tick-);/*Private function prototypes-*/extern unsigned char datasize;extern volatile unsigned char cnt;/*Function Name:main*Description:Main program*Input:None*Output:None*Return:Non
18、e*Attention:None*/int main(void)/*USART configuration*/USART3_Config();RED_ON();BLUE_ON();GREEN_ON();Delay(100000);BLUE_OFF();RED_OFF();GREEN_OFF();/*Infinite loop*/while(1)uint8_t i=0;RS_485_TX_ENABLE();printf(rn up up day!);for(i=0;i50;i+)GREEN_ON();Delay(500000);GREEN_OFF();Delay(500000);RS_485_RX_ENABLE();while(data0=0 x00)RED_ON();Delay(500000);RED_OFF();Delay(500000);memset(data,0,size);