import serial
import time

# 配置串口（请根据实际情况修改设备名）
PORT = '/dev/ttyS0'  # 或 '/dev/ttyUSB0'
BAUDRATE = 115200

try:
    # 打开串口
    ser = serial.Serial(PORT, BAUDRATE, timeout=1)
    print(f"✅ 已打开串口 {PORT}")

    # 发送数据
    data_to_send = b'123456\n'

    # 持续读取数据（注意：此时串口是打开的！）
    print("📥 开始监听串口数据...")
    while True:
        ser.write(data_to_send)
        print("📤 已发送数据")
        try:
            line = ser.readline()
            if line:
                print("接收到:", line.hex())
        except serial.SerialException as e:
            print("❌ 串口异常:", e)
            break
        time.sleep(1)

except serial.SerialException as e:
    print(f"❌ 无法打开串口 {PORT}: {e}")
except KeyboardInterrupt:
    print("\n🛑 用户中断")
finally:
    if 'ser' in locals() and ser.is_open:
        ser.close()
        print("🔌 串口已关闭")