update: 增加帧尾
This commit is contained in:
117
serial_module.c
117
serial_module.c
@@ -1,6 +1,5 @@
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#define PY_SSIZE_T_CLEAN
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#include <Python.h>
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#include <stdint.h>
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#include <string.h>
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#include <stdlib.h>
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#include <unistd.h>
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@@ -11,35 +10,34 @@
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#include <pthread.h> // 引入 pthread 库
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// 宏定义
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// #define USE_FEC
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#ifdef USE_FEC
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#define FEC_SIZE 32 // 前向纠错冗余数据大小
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#else
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#define FEC_SIZE 0 // 前向纠错冗余数据大小
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#endif
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#define FRAME_HEADER 0xAA55 // 帧头
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#define FRAME_TAIL 0x0D7E // 帧尾
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#define FRAME_SIZE (240) // 每帧大小
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#define HEADER_SIZE (4) // 帧头 + 帧序号 + 数据长度
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#define TAIL_SIZE (2) // 帧尾
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#define CHECKSUM_SIZE (4) // CRC32 校验和大小(4 字节)
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#define DATA_SIZE (FRAME_SIZE - HEADER_SIZE - CHECKSUM_SIZE - FEC_SIZE) // 数据段大小
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#define DATA_SIZE (FRAME_SIZE - HEADER_SIZE - CHECKSUM_SIZE - FEC_SIZE - TAIL_SIZE) // 数据段大小
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#define RING_BUFFER_SIZE (1024 * 10) // 环形缓冲区大小 - default 10KB
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#define QUEUE_MAX_SIZE 1024 // 队列最大容量
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// 全局变量
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static by_serial_t serial_port;
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static by_ringbuf_t ring_buffer;
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static uint8_t send_buffer[FRAME_SIZE];
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static uint8_t frame_counter = 0;
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static uint8_t data_len = 0;
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uint8_t output_data[8192];
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static unsigned char send_buffer[FRAME_SIZE];
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static unsigned char frame_counter = 0;
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static unsigned char data_len = 0;
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unsigned char output_data[8192];
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static int output_len = 0;
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// 定义队列结构体
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typedef struct
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{
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uint8_t *data;
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unsigned char *data;
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int length;
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} FrameData;
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@@ -48,71 +46,82 @@ static FrameData frame_queue[QUEUE_MAX_SIZE]; // 存储接收
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static int queue_head = 0; // 队列头指针
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static int queue_tail = 0; // 队列尾指针
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static pthread_mutex_t queue_mutex = PTHREAD_MUTEX_INITIALIZER; // 保护队列的互斥锁
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static bool stop_receiving = false; // 控制接收线程停止的标志
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static int stop_receiving = false; // 控制接收线程停止的标志
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// 前向声明
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void *receive_thread_func(void *arg);
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// 计算 CRC32 校验和
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uint32_t calculate_crc32(const uint8_t *data, size_t length)
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unsigned long calculate_crc32(const unsigned char *data, size_t length)
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{
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return crc32(0, data, length);
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}
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// 解析一帧数据
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int parse_frame(by_ringbuf_t *ringbuf, uint8_t *output_data, int *output_len)
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int parse_frame(by_ringbuf_t *ringbuf, unsigned char *output_data, int *output_len)
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{
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uint8_t frame[FRAME_SIZE];
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unsigned char frame[FRAME_SIZE];
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unsigned char buffer[FRAME_SIZE * 3];
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int available_data = by_ringbuf_available_data(ringbuf);
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while (by_ringbuf_available_data(ringbuf) < FRAME_SIZE)
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{
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int ret = by_serial_read(&serial_port, buffer, FRAME_SIZE);
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if (ret > 0)
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{
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by_ringbuf_append(&ring_buffer, buffer, ret);
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}
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}
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// TODO 有无必要
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// 检查是否有足够的数据解析一帧
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if (available_data < HEADER_SIZE + CHECKSUM_SIZE + FEC_SIZE)
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if (available_data < FRAME_SIZE)
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{
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return -1; // 数据不足,无法解析
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}
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// 查找帧头
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uint16_t header = FRAME_HEADER;
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int header_pos = by_ringbuf_find(ringbuf, (uint8_t *)&header, 2);
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unsigned short header = FRAME_HEADER;
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unsigned short tail = FRAME_TAIL;
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int header_pos = by_ringbuf_find(ringbuf, (unsigned char *)&header, 2);
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if (header_pos < 0)
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{
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return -1; // 没有找到帧头
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}
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// 弹出帧头之前的数据
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by_ringbuf_pop(ringbuf, frame, header_pos);
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// 检查是否有足够的数据解析一帧
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if (by_ringbuf_available_data(ringbuf) < FRAME_SIZE)
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{
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return -1; // 数据不足,无法解析
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}
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// 读取帧数据
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by_ringbuf_pop(ringbuf, frame, FRAME_SIZE);
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// 读取帧数据
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by_ringbuf_pop(ringbuf, frame, HEADER_SIZE);
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int tail_pos = by_ringbuf_find(ringbuf, (unsigned char *)&tail, 2);
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if (tail_pos < FRAME_SIZE - HEADER_SIZE - TAIL_SIZE - 1)
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{
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printf(" fail, next frame header pos: %d\n", header_pos);
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return -2; // 下一帧帧头小于 FRAME_SIZE,丢弃该帧
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}
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else
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{
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by_ringbuf_pop(ringbuf, frame + HEADER_SIZE, tail_pos + TAIL_SIZE);
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}
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// 解析帧序号、有效数据长度、数据段和 CRC32
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uint8_t seq = frame[2];
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uint8_t valid_data_len = frame[2 + 1];
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uint8_t *data_segment = &frame[2 + 1 + 1];
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uint32_t received_crc = *(uint32_t *)&frame[2 + 1 + 1 + DATA_SIZE];
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unsigned char seq = frame[2];
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unsigned char valid_data_len = frame[2 + 1];
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unsigned char *data_segment = &frame[2 + 1 + 1];
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unsigned int received_crc = *(unsigned long *)&frame[HEADER_SIZE + DATA_SIZE];
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// 计算 CRC32 校验
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uint32_t calculated_crc = calculate_crc32(frame, HEADER_SIZE + DATA_SIZE + FEC_SIZE);
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unsigned int calculated_crc = calculate_crc32(frame, HEADER_SIZE + DATA_SIZE + FEC_SIZE);
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if (received_crc != calculated_crc)
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{
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printf("CRC mismatch! Expected: %08X, Received: %08X\n", calculated_crc, received_crc);
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return -1; // CRC 校验失败,丢弃该帧
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return -2; // CRC 校验失败,丢弃该帧,严重错误
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}
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// 将有效数据拼接到输出缓冲区
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memcpy(&output_data[*output_len], data_segment, valid_data_len);
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*output_len += valid_data_len;
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printf("output len: %d\n", *output_len);
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printf("Received frame: seq=%d, len=%d\r\n", seq, valid_data_len);
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// 判断是否为最后一帧
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if (valid_data_len < DATA_SIZE)
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{
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@@ -125,19 +134,8 @@ int parse_frame(by_ringbuf_t *ringbuf, uint8_t *output_data, int *output_len)
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// 接收线程函数
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void *receive_thread_func(void *arg)
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{
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while (!stop_receiving)
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{
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// 从串口读取数据到环形缓冲区
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uint8_t buffer[FRAME_SIZE];
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int ret = by_serial_read(&serial_port, buffer, FRAME_SIZE);
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if (ret > 0)
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{
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by_ringbuf_append(&ring_buffer, buffer, ret);
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}
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// 尝试解析环形缓冲区中的数据
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while (1)
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{
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int parse_result = parse_frame(&ring_buffer, output_data, &output_len);
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@@ -166,12 +164,12 @@ void *receive_thread_func(void *arg)
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printf("Parsed data length: %d\n", output_len);
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break; // 数据不足或解析失败,退出循环
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}
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else if (parse_result == -1)
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else if (parse_result == -2)
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{
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output_len = 0;
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break; // 数据不足或解析失败,退出循环
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}
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}
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usleep(1000); // 避免占用过多 CPU
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}
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return NULL;
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@@ -185,20 +183,17 @@ static PyObject *serial_init(PyObject *self, PyObject *args)
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{
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return NULL;
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}
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if (by_serial_init(&serial_port, dev_name) != 0)
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{
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PyErr_SetString(PyExc_IOError, "Failed to initialize serial port");
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return NULL;
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}
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// 初始化环形缓冲区
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if (by_ringbuf_init(&ring_buffer, RING_BUFFER_SIZE) != 0)
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{
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PyErr_SetString(PyExc_IOError, "Failed to initialize ring buffer");
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return NULL;
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}
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// 启动接收线程
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pthread_t receive_thread;
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stop_receiving = false;
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@@ -207,7 +202,6 @@ static PyObject *serial_init(PyObject *self, PyObject *args)
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PyErr_SetString(PyExc_RuntimeError, "Failed to start receive thread");
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return NULL;
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}
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Py_RETURN_NONE;
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}
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@@ -220,16 +214,13 @@ static PyObject *serial_send(PyObject *self, PyObject *args)
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{
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return NULL;
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}
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size_t offset = 0;
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while (offset < length)
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{
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memset(send_buffer, 0, FRAME_SIZE);
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// 构造帧头
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uint16_t header = FRAME_HEADER;
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unsigned short header = FRAME_HEADER;
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memcpy(send_buffer, &header, 2);
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// 构造帧序号和数据长度
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memcpy(send_buffer + 2, &frame_counter, 1);
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if (length - offset > DATA_SIZE)
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@@ -241,28 +232,24 @@ static PyObject *serial_send(PyObject *self, PyObject *args)
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data_len = length - offset;
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}
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memcpy(send_buffer + 3, &data_len, 1);
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// 拷贝该帧对应数据段
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memcpy(send_buffer + HEADER_SIZE, data + offset, data_len);
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printf("Received frame: seq=%d, len=%d\r\n", frame_counter, data_len);
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// 计算 CRC32 校验和
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uint32_t crc = calculate_crc32(send_buffer, HEADER_SIZE + DATA_SIZE + FEC_SIZE);
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unsigned long crc = calculate_crc32(send_buffer, HEADER_SIZE + DATA_SIZE + FEC_SIZE);
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memcpy(send_buffer + HEADER_SIZE + DATA_SIZE + FEC_SIZE, &crc, CHECKSUM_SIZE);
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unsigned short tail = FRAME_TAIL;
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memcpy(send_buffer + HEADER_SIZE + DATA_SIZE + FEC_SIZE + CHECKSUM_SIZE, &tail, TAIL_SIZE);
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// 发送帧
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if (by_serial_write(&serial_port, (const char *)send_buffer, FRAME_SIZE) != 0)
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{
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PyErr_SetString(PyExc_IOError, "Failed to send data over serial port");
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return NULL;
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}
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offset += DATA_SIZE;
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frame_counter++;
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usleep(80000);
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}
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frame_counter = 0;
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Py_RETURN_NONE;
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}
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@@ -277,12 +264,10 @@ static PyObject *serial_receive(PyObject *self, PyObject *args)
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PyErr_SetString(PyExc_IOError, "No data available in the queue");
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return NULL;
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}
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// 获取队列中最早的数据包
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FrameData frame = frame_queue[queue_head];
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queue_head = (queue_head + 1) % QUEUE_MAX_SIZE;
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pthread_mutex_unlock(&queue_mutex);
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// 返回解析后的数据
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PyObject *result = Py_BuildValue("y#", frame.data, frame.length);
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free(frame.data); // 释放内存
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