CodePudding user response:
There is something wrong with the oscilloscope use,CodePudding user response:
(1) the oscilloscope triggering level is set too high, so can't capture the clock signal, (2) 74 hc595 are needed more than it can achieve MHz clock frequency, if this time oscilloscope tone is too small, when you put it in one fell swoop in the past, when you put the tone bigger (such as the time base: try 1 s), (3) you may not use the oscilloscope so you can't see (if you will use the oscilloscope is when the words didn't say,) (4) may be your use of oscilloscope is too low (less than the signal bandwidth is too small to capture), the average bandwidth of about 100 m of the oscilloscope can see,