代码
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, 19200, timeout_char=200)

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