pp协议 0x8021
时间: 2023-07-21 10:56:56 浏览: 208
PP协议是一种点对点协议,用于在串行通信线路上封装网络层数据。PP协议中定义了很多控制字段,其中0x8021是一个控制字段的值,表示对方请求发送数据。
具体来说,在PP协议中,每个数据包都由固定长度的头部和一个可变长度的负载组成。头部中包含了一些控制字段,用于表示包的类型、序列号、协议类型等信息。0x8021就是一个控制字段的取值,表示对方请求发送数据,即请求发送一个数据包。当收到一个带有0x8021控制字段的数据包时,发送方应该立即回复一个带有0x8023控制字段的数据包,表示同意接收数据。
需要注意的是,PP协议是一种比较老旧的协议,现在通常被PPP协议所取代。如果需要在现代网络中进行点对点通信,建议使用更先进的协议,例如VPN或SSL/TLS等。
相关问题
生成一段代码,实现STM32通过485协议只接收数据0x11,0x22,0x33,之后发送0x44,0x55,0x66
以下是一段示例代码,实现STM32通过485协议只接收数据0x11,0x22,0x33,之后发送0x44,0x55,0x66:
```c
#include "stm32f4xx.h"
#define USARTx USART1
#define USARTx_CLK RCC_APB2Periph_USART1
#define USARTx_IRQn USART1_IRQn
#define USARTx_IRQHandler USART1_IRQHandler
#define GPIOx GPIOA
#define GPIOx_CLK RCC_AHB1Periph_GPIOA
#define GPIOx_PIN_TX GPIO_Pin_9
#define GPIOx_PIN_RX GPIO_Pin_10
#define GPIOx_PIN_DE GPIO_Pin_8
#define RX_BUFFER_SIZE 10
uint8_t rxBuffer[RX_BUFFER_SIZE];
uint8_t rxIndex = 0;
void initUSART(void) {
GPIO_InitTypeDef GPIO_InitStructure;
USART_InitTypeDef USART_InitStructure;
RCC_AHB1PeriphClockCmd(GPIOx_CLK, ENABLE);
RCC_APB2PeriphClockCmd(USARTx_CLK, ENABLE);
GPIO_InitStructure.GPIO_Pin = GPIOx_PIN_TX | GPIOx_PIN_RX | GPIOx_PIN_DE;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;
GPIO_Init(GPIOx, &GPIO_InitStructure);
GPIO_PinAFConfig(GPIOx, GPIO_PinSource9, GPIO_AF_USART1);
GPIO_PinAFConfig(GPIOx, GPIO_PinSource10, GPIO_AF_USART1);
USART_InitStructure.USART_BaudRate = 9600;
USART_InitStructure.USART_WordLength = USART_WordLength_8b;
USART_InitStructure.USART_StopBits = USART_StopBits_1;
USART_InitStructure.USART_Parity = USART_Parity_No;
USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
USART_Init(USARTx, &USART_InitStructure);
USART_ITConfig(USARTx, USART_IT_RXNE, ENABLE);
USART_DirectionModeCmd(USARTx, USART_Mode_Tx, ENABLE);
USART_DirectionModeCmd(USARTx, USART_Mode_Rx, ENABLE);
USART_Cmd(USARTx, ENABLE);
}
void USARTx_IRQHandler(void) {
if (USART_GetITStatus(USARTx, USART_IT_RXNE) != RESET) {
uint8_t data = USART_ReceiveData(USARTx);
if (data == 0x11 || data == 0x22 || data == 0x33) {
rxBuffer[rxIndex++] = data;
if (rxIndex == RX_BUFFER_SIZE) {
rxIndex = 0;
}
}
}
}
void sendData(void) {
USART_DirectionModeCmd(USARTx, USART_Mode_Tx, ENABLE);
USART_SendData(USARTx, 0x44);
while (USART_GetFlagStatus(USARTx, USART_FLAG_TC) == RESET);
USART_SendData(USARTx, 0x55);
while (USART_GetFlagStatus(USARTx, USART_FLAG_TC) == RESET);
USART_SendData(USARTx, 0x66);
while (USART_GetFlagStatus(USARTx, USART_FLAG_TC) == RESET);
USART_DirectionModeCmd(USARTx, USART_Mode_Tx, DISABLE);
}
int main(void) {
initUSART();
while (1) {
if (rxBuffer[0] == 0x11 && rxBuffer[1] == 0x22 && rxBuffer[2] == 0x33) {
sendData();
}
}
}
```
stm32通讯协议代码
针对不同的通讯协议,STM32的代码实现也会有所不同。以下是常见的几种通讯协议的代码实现:
1. SPI通讯协议代码示例:
```c
#include "stm32f10x.h"
#define SPI_PORT GPIOA
#define SPI_NSS GPIO_Pin_4
#define SPI_SCK GPIO_Pin_5
#define SPI_MISO GPIO_Pin_6
#define SPI_MOSI GPIO_Pin_7
void spi_init(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
GPIO_InitStructure.GPIO_Pin = SPI_NSS | SPI_SCK | SPI_MISO | SPI_MOSI;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_Init(SPI_PORT, &GPIO_InitStructure);
SPI_InitTypeDef SPI_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1, ENABLE);
SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
SPI_InitStructure.SPI_Mode = SPI_Mode_Master;
SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;
SPI_InitStructure.SPI_CPOL = SPI_CPOL_Low;
SPI_InitStructure.SPI_CPHA = SPI_CPHA_1Edge;
SPI_InitStructure.SPI_NSS = SPI_NSS_Hard;
SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_16;
SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
SPI_InitStructure.SPI_CRCPolynomial = 7;
SPI_Init(SPI1, &SPI_InitStructure);
SPI_Cmd(SPI1, ENABLE);
}
uint8_t spi_transfer(uint8_t data)
{
while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_TXE) == RESET);
SPI_I2S_SendData(SPI1, data);
while (SPI_I2S_GetFlagStatus(SPI1, SPI_I2S_FLAG_RXNE) == RESET);
return SPI_I2S_ReceiveData(SPI1);
}
```
2. I2C通讯协议代码示例:
```c
#include "stm32f10x.h"
#define I2C_PORT GPIOB
#define I2C_SCL GPIO_Pin_6
#define I2C_SDA GPIO_Pin_7
void i2c_init(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);
GPIO_InitStructure.GPIO_Pin = I2C_SCL | I2C_SDA;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_OD;
GPIO_Init(I2C_PORT, &GPIO_InitStructure);
I2C_InitTypeDef I2C_InitStructure;
RCC_APB1PeriphClockCmd(RCC_APB1Periph_I2C1, ENABLE);
I2C_InitStructure.I2C_Mode = I2C_Mode_I2C;
I2C_InitStructure.I2C_DutyCycle = I2C_DutyCycle_2;
I2C_InitStructure.I2C_OwnAddress1 = 0x00;
I2C_InitStructure.I2C_Ack = I2C_Ack_Enable;
I2C_InitStructure.I2C_AcknowledgedAddress = I2C_AcknowledgedAddress_7bit;
I2C_InitStructure.I2C_ClockSpeed = 100000;
I2C_Init(I2C1, &I2C_InitStructure);
I2C_Cmd(I2C1, ENABLE);
}
void i2c_start(void)
{
I2C_GenerateSTART(I2C1, ENABLE);
while (!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_MODE_SELECT));
}
void i2c_stop(void)
{
I2C_GenerateSTOP(I2C1, ENABLE);
}
void i2c_write(uint8_t data)
{
I2C_SendData(I2C1, data);
while (!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_TRANSMITTED));
}
uint8_t i2c_read_ack(void)
{
I2C_AcknowledgeConfig(I2C1, ENABLE);
while (!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_RECEIVED));
return I2C_ReceiveData(I2C1);
}
uint8_t i2c_read_nack(void)
{
I2C_AcknowledgeConfig(I2C1, DISABLE);
while (!I2C_CheckEvent(I2C1, I2C_EVENT_MASTER_BYTE_RECEIVED));
return I2C_ReceiveData(I2C1);
}
```
3. UART通讯协议代码示例:
```c
#include "stm32f10x.h"
#define UART_PORT GPIOA
#define UART_TX GPIO_Pin_9
#define UART_RX GPIO_Pin_10
void uart_init(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
GPIO_InitStructure.GPIO_Pin = UART_TX;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_Init(UART_PORT, &GPIO_InitStructure);
GPIO_InitStructure.GPIO_Pin = UART_RX;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
GPIO_Init(UART_PORT, &GPIO_InitStructure);
USART_InitTypeDef USART_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_USART1, ENABLE);
USART_InitStructure.USART_BaudRate = 9600;
USART_InitStructure.USART_WordLength = USART_WordLength_8b;
USART_InitStructure.USART_StopBits = USART_StopBits_1;
USART_InitStructure.USART_Parity = USART_Parity_No;
USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
USART_Init(USART1, &USART_InitStructure);
USART_Cmd(USART1, ENABLE);
}
void uart_send(uint8_t data)
{
while (USART_GetFlagStatus(USART1, USART_FLAG_TXE) == RESET);
USART_SendData(USART1, data);
}
uint8_t uart_receive(void)
{
while (USART_GetFlagStatus(USART1, USART_FLAG_RXNE) == RESET);
return USART_ReceiveData(USART1);
}
```
以上代码仅供参考,具体实现需要根据具体的硬件和通讯协议进行调整。