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import sensor, image, time from pyb import Pin, Timer
tim = Timer( 4 ,freq = 500)
tim.channel(2,Timer.PWM,pin=Pin("P8"),pulse_width_percent=50)
while(True): time.sleep_ms(1000)
换了另一个就对了,这该怎么检查
检查引脚焊接,如果焊接没问题,寄回检查。