#!/usr/bin/env python3
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# -*- coding: utf-8 -*-
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"""
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校验和调试工具 - 详细分析STM32输出的原始数据帧
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"""
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import serial
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import struct
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import time
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# 协议常量
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FRAME_HEADER = bytes([0xAA, 0x55])
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FRAME_FOOTER = bytes([0x0D, 0x0A])
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TYPE_GPS = 0x01
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TYPE_IMU = 0x02
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def calculate_checksum(data):
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"""计算16位累加和"""
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return sum(data) & 0xFFFF
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def main():
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port = "COM28"
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baudrate = 921600
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print(f"打开串口 {port} @ {baudrate}")
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try:
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ser = serial.Serial(port, baudrate, timeout=1)
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print("串口已打开，接收数据中...\n")
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buffer = bytearray()
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frame_count = 0
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while frame_count < 5: # 只分析前5帧
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if ser.in_waiting > 0:
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data = ser.read(ser.in_waiting)
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buffer.extend(data)
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# 查找帧头
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while len(buffer) >= 9:
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idx = buffer.find(FRAME_HEADER)
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if idx == -1:
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buffer.clear()
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break
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if idx > 0:
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buffer = buffer[idx:]
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# 检查是否有足够的数据解析帧头
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if len(buffer) < 5:
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break
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frame_type = buffer[2]
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payload_len = struct.unpack('<H', buffer[3:5])[0]
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expected_len = 2 + 1 + 2 + payload_len + 2 + 2
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print(f"\n[调试] 发现帧头 @ buffer[{idx}], 类型=0x{frame_type:02X}, 载荷长度={payload_len}, 需要={expected_len}, 可用={len(buffer)}")
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if len(buffer) < expected_len:
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print(f"[调试] 数据不足，等待更多数据...")
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break
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# 提取完整帧
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frame = buffer[:expected_len]
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buffer = buffer[expected_len:]
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frame_count += 1
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# 详细分析这一帧
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print(f"{'='*70}")
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print(f"帧 #{frame_count} - 类型: 0x{frame_type:02X} ({'GPS' if frame_type == TYPE_GPS else 'IMU' if frame_type == TYPE_IMU else '未知'})")
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print(f"{'='*70}")
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# 打印原始十六进制
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print(f"原始数据 ({len(frame)} 字节):")
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hex_str = ' '.join(f'{b:02X}' for b in frame)
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for i in range(0, len(hex_str), 72):
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print(f" {hex_str[i:i+72]}")
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# 解析各个部分
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print(f"\n帧结构分析:")
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print(f" 帧头: {frame[:2].hex().upper()} (应为 AA55)")
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print(f" 类型: 0x{frame[2]:02X}")
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print(f" 长度: {payload_len} (0x{frame[3]:02X}{frame[4]:02X})")
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payload = frame[5:5+payload_len]
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print(f" 载荷: {payload.hex().upper()} ({len(payload)} 字节)")
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checksum_received = struct.unpack('<H', frame[5+payload_len:5+payload_len+2])[0]
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print(f" 校验和(接收): 0x{checksum_received:04X}")
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footer = frame[5+payload_len+2:5+payload_len+4]
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print(f" 帧尾: {footer.hex().upper()} (应为 0D0A)")
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# 计算校验和 - 三种方式
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print(f"\n校验和验证:")
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# 方式1: Type + Length + Payload (正确方式)
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checksum_data1 = frame[2:5+payload_len]
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checksum_calc1 = calculate_checksum(checksum_data1)
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match1 = "✓" if checksum_calc1 == checksum_received else "✗"
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print(f" 方式1 (Type+Len+Payload): 0x{checksum_calc1:04X} {match1}")
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print(f" 计算范围: 字节[2:{5+payload_len}] = {checksum_data1.hex().upper()}")
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# 方式2: 包含帧头 (错误方式)
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checksum_data2 = frame[0:5+payload_len]
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checksum_calc2 = calculate_checksum(checksum_data2)
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match2 = "✓" if checksum_calc2 == checksum_received else "✗"
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print(f" 方式2 (含帧头AA55): 0x{checksum_calc2:04X} {match2}")
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# 方式3: 只有Payload (错误方式)
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checksum_calc3 = calculate_checksum(payload)
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match3 = "✓" if checksum_calc3 == checksum_received else "✗"
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print(f" 方式3 (仅Payload): 0x{checksum_calc3:04X} {match3}")
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# 计算差值
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diff = checksum_received - checksum_calc1
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print(f"\n 差值 (接收 - 方式1): {diff} (0x{diff & 0xFFFF:04X})")
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print()
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if frame_count >= 5:
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break
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time.sleep(0.01)
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ser.close()
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print("分析完成")
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except Exception as e:
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print(f"错误: {e}")
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import traceback
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traceback.print_exc()
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if __name__ == "__main__":
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main()
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