@kidswong999 我发现电脑串口发送数据后，电脑串口会收到一个返回的十六进制的 00 。但是openmv 按照示例写发送，电脑还是什么都收到不到。

@kidswong999 接线对的，可以收到数据。引脚焊接也没问题。

# UART Control
#
# This example shows how to use the serial port on your OpenMV Cam. Attach pin
# P4 to the serial input of a serial LCD screen to see "Hello World!" printed
# on the serial LCD display.

import time
from pyb import UART

# Always pass UART 3 for the UART number for your OpenMV Cam.
# The second argument is the UART baud rate. For a more advanced UART control
# example see the BLE-Shield driver.
uart = UART(3, 9600)

while(True):
    uart.write("Hello World!\r")
    time.sleep_ms(1000)

固件版本：4.4.2
IDE版本： 3.0.3