maixduino串口通信

from fpioa_manager import fmimport time, sensor, imagefrom machine import UART
fm.register(9, fm.fpioa.UART2_TX, force=True)fm.register(10, fm.fpioa.UART2_RX, force=True)
uart_A = UART(UART.UART2, 115200, 8, 1, 0, timeout=1000, read_buf_len=4096)
write_str = "hello world"sensor.reset()sensor.set_pixformat(sensor.RGB565)sensor.set_framesize(sensor.QVGA)sensor.skip_frames(time = 2000)while True:        img = sensor.snapshot()        for i in range(20):            uart_A.write(write_str)            print("string = ",write_str)uart_B.deinit()del uart_B
怎么无法再电脑位机接收到数据