DSO-138 Oscilloscope

I bought a DSO-138 oscilloscope for $30, and I’m not sure if I can get much use out of it. One thing missing is an external trigger line to sync signals. Another thing missing is 20MHz vs it’s optimistically rated 200kHz.


I also within 2 days later Groggy gave me a free ancient Tektronix 2MHz oscilloscope.


I am here interested in catching the output signal from my Uno, to see if my LED library is outputting the right signal. With this scope even that is hard to do. However I do not have a proper trigger set up for this experiment. Maybe it’ll be easier once I trigger properly.

I need to measure the duration of the on vs off signal with 62ns precision, counting how many 62ns increments are there for 1 vs 0 signals. It may be doable since the signal is clearly visible. The beam is also faint when I magnify it which will be needed to see what’s going on.

Well the cheap modern scope does not even detect those signals nor sync to them…

Bottom line: Get a scope with a trigger input an a probe or two inputs.


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