STM32 与光照传感器 RS485 通信代码示例

#include <stdint.h> #include "stm32f4xx.h"

// \u5B9A\u4E49 RS485 \u63A7\u5236\u5F15\u811A #define RS485_DIR_PIN GPIO_Pin_5 #define RS485_DIR_PORT GPIOC

// \u5B9A\u4E49 RS485 \u901A\u4FE1\u5730\u5740 #define DEVICE_ADDRESS 0x01

// \u5B9A\u4E49\u529F\u80FD\u7801 #define READ_LIGHT_INTENSITY 0x01

// \u5B9A\u4E49\u53D1\u9001\u548C\u63A5\u6536\u7F13\u51B5\u5927\u5C0F #define TX_BUFFER_SIZE 8 #define RX_BUFFER_SIZE 8

// \u5B9A\u4E49\u53D1\u9001\u548C\u63A5\u6536\u7F13\u51B5 uint8_t txBuffer[TX_BUFFER_SIZE]; uint8_t rxBuffer[RX_BUFFER_SIZE];

// \u521D\u59CB\u5316 RS485 \u901A\u4FE1 void RS485_Init() { GPIO_InitTypeDef GPIO_InitStruct;

// \u521D\u59CB\u5316 RS485 \u63A7\u5236\u5F15\u811A
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOC, ENABLE);
GPIO_InitStruct.GPIO_Pin = RS485_DIR_PIN;
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_OUT;
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;
GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_Init(RS485_DIR_PORT, &GPIO_InitStruct);

// \u9ED8\u8BA4\u4E3A\u63A5\u6536\u6A21\u5F0F
GPIO_ResetBits(RS485_DIR_PORT, RS485_DIR_PIN);

}

// \u53D1\u9001\u6570\u636E void RS485_SendData(uint8_t* data, uint8_t length) { // \u8BBE\u7F6E\u4E3A\u53D1\u9001\u6A21\u5F0F GPIO_SetBits(RS485_DIR_PORT, RS485_DIR_PIN);

// \u53D1\u9001\u6570\u636E
for (uint8_t i = 0; i < length; i++) {
    USART_SendData(USART1, data[i]);
    while (USART_GetFlagStatus(USART1, USART_FLAG_TXE) == RESET);
}

// \u7B49\u5F85\u53D1\u9001\u5B8C\u6210
while (USART_GetFlagStatus(USART1, USART_FLAG_TC) == RESET);

// \u8BBE\u7F6E\u4E3A\u63A5\u6536\u6A21\u5F0F
GPIO_ResetBits(RS485_DIR_PORT, RS485_DIR_PIN);

}

// \u63A5\u6536\u6570\u636E void RS485_ReceiveData(uint8_t* data, uint8_t length) { // \u8BBE\u7F6E\u4E3A\u63A5\u6536\u6A21\u5F0F GPIO_ResetBits(RS485_DIR_PORT, RS485_DIR_PIN);

// \u63A5\u6536\u6570\u636E
for (uint8_t i = 0; i < length; i++) {
    while (USART_GetFlagStatus(USART1, USART_FLAG_RXNE) == RESET);
    data[i] = USART_ReceiveData(USART1);
}

}

// \u521D\u59CB\u5316 USART1 void USART1_Init() { GPIO_InitTypeDef GPIO_InitStruct; USART_InitTypeDef USART_InitStruct;

// \u521D\u59CB\u5316 USART1 \u7684 GPIO \u5F15\u811A
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_9 | GPIO_Pin_10;
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;
GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_Init(GPIOA, &GPIO_InitStruct);

GPIO_PinAFConfig(GPIOA, GPIO_PinSource9, GPIO_AF_USART1);
GPIO_PinAFConfig(GPIOA, GPIO_PinSource10, GPIO_AF_USART1);

// \u521D\u59CB\u5316 USART1
RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);
USART_InitStruct.USART_BaudRate = 9600;
USART_InitStruct.USART_WordLength = USART_WordLength_8b;
USART_InitStruct.USART_StopBits = USART_StopBits_1;
USART_InitStruct.USART_Parity = USART_Parity_No;
USART_InitStruct.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
USART_InitStruct.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
USART_Init(USART1, &USART_InitStruct);

USART_Cmd(USART1, ENABLE);

}

// \u5411\u5149\u7167\u4F20\u611F\u5668\u53D1\u9001\u8BFB\u53D6\u5149\u5F3A\u5EA6\u7684\u547D\u4EE4 void ReadLightIntensity() { txBuffer[0] = DEVICE_ADDRESS; txBuffer[1] = READ_LIGHT_INTENSITY;

RS485_SendData(txBuffer, 2);

}

int main(void) { // \u521D\u59CB\u5316 RS485 \u901A\u4FE1\u548C USART1 RS485_Init(); USART1_Init();

while (1) {
    // \u53D1\u9001\u8BFB\u53D6\u5149\u5F3A\u5EA6\u7684\u547D\u4EE4
    ReadLightIntensity();
  
    // \u63A5\u6536\u5149\u7167\u4F20\u611F\u5668\u8FD4\u56DE\u7684\u6570\u636E
    RS485_ReceiveData(rxBuffer, 2);
  
    // \u5904\u7406\u63A5\u6536\u5230\u7684\u6570\u636E
    uint16_t intensity = (rxBuffer[0] << 8) | rxBuffer[1];
  
    // \u5728\u6B64\u5904\u6DFB\u52A0\u4F60\u60F3\u8981\u7684\u5904\u7406\u903C\u8F91\uff0c\u6BD4\u5982\u6253\u5370\u5149\u5F3A\u5EA6\u503C
  
    // \u5EF6\u65F6\u4E00\u6BB5\u65F6\u95F4
    for (uint32_t i = 0; i < 1000000; i++);
}

}