用python写一个基于串口的ymodem升级工具

好的，下面是基于Python的YModem升级工具。首先需要安装 `pyserial` 库来进行串口通信。

import os
import sys
import time
from typing import Tuple
import serial


def send_packet(serial_port: serial.Serial, packet: bytes) -> None:
    """发送一个数据包"""
    serial_port.write(packet)
    serial_port.flush()


def read_packet(serial_port: serial.Serial) -> Tuple[bytes, int]:
    """读取一个数据包"""
    packet_data = serial_port.read(1024)
    packet_length = len(packet_data)
    return packet_data, packet_length


def send_ymodem_file(serial_port: serial.Serial, file_path: str) -> None:
    """发送YModem文件"""
    file_size = os.path.getsize(file_path)
    file_name = os.path.basename(file_path)
    file_mode = "wb"
    file = open(file_path, file_mode)

    # 发送起始包
    send_packet(serial_port, bytes([0x00]))
    send_packet(serial_port, bytes([0x06]))
    packet, packet_length = read_packet(serial_port)
    if packet_length != 1 or packet[0] != 0x43:
        print("Failed to start YModem transfer.")
        return

    # 发送文件名和文件大小
    packet_number = 0
    packet_data = bytes([0x00] * 128)
    packet_data = packet_data[:len(file_name)] + file_name.encode() + bytes([0x00] * (128 - len(file_name)))
    packet_data = packet_data[:len(str(file_size))] + str(file_size).encode() + bytes([0x00] * (128 - len(str(file_size))))
    while True:
        send_packet(serial_port, bytes([0x01, packet_number, 0xFF - packet_number, 0x00]))
        send_packet(serial_port, packet_data)
        packet, packet_length = read_packet(serial_port)
        if packet_length == 1 and packet[0] == 0x06:
            break
        elif packet_length == 1 and packet[0] == 0x15:
            print("Receiver canceled transfer.")
            return
        packet_number += 1

    # 发送文件数据
    packet_number = 1
    while True:
        packet_data = file.read(1024)
        if not packet_data:
            # 发送结束包
            send_packet(serial_port, bytes([0x01, packet_number, 0xFF - packet_number, 0x00]))
            send_packet(serial_port, bytes([0x00] * 128))
            packet, packet_length = read_packet(serial_port)
            if packet_length == 1 and packet[0] == 0x06:
                print("Transfer complete.")
            else:
                print("Transfer failed.")
            break
        send_packet(serial_port, bytes([0x01, packet_number, 0xFF - packet_number, 0x00]))
        send_packet(serial_port, packet_data)
        packet, packet_length = read_packet(serial_port)
        if packet_length == 1 and packet[0] == 0x06:
            packet_number += 1
        elif packet_length == 1 and packet[0] == 0x15:
            print("Receiver canceled transfer.")
            return


if __name__ == "__main__":
    serial_port = serial.Serial(port="COM1", baudrate=115200, timeout=1)
    file_path = "test.txt"
    send_ymodem_file(serial_port, file_path)

这个工具可以通过串口发送文件，实现YModem升级。其中，需要将 `COM1` 替换为实际的串口名称，将 `test.txt` 替换为实际的文件路径。在发送文件时，程序会先发送起始包，然后发送文件名和文件大小，最后按照每包1024字节的大小发送文件数据，并在最后发送结束包。在发送过程中，程序会读取接收方的反馈信息，如果发生错误则会打印相关提示信息。