measure output with oscilloscope

Projects General Guidance
1

Hi

I want to measure the output of the Blink example with the oscilloscope Tektronix TDS 1001. In the example the Build-In LED pin on an Arduino Zero should be 1s high, 1s low. This works. But if I measure it with the oscilloscope I get a weird sine wave with much noise. Not a square wave, definitely false.

Does someone know what are the settings for the oscilloscope to measure it? For example coupling, ... I have tried a lot of different setting, but I get always the same result.

Thanks

2

Is your scope's ground connected to Arduino ground?

3

And channel mode set to DC?

4

Oscilloscope-GND connected to Arduino GND
DC-coupling
1s/div
2V/div
Trigger: Auto, rising edge, 2V

5

Why should I set it to DC? I see now something with AC
yes ground is connected on the arduino ground

I found out want my problem is:

I measure a 10us peak which occurs every second. So very different timescales. Is there a solution that I can see this peak on the oscilloscope with a timesetting of 500ms for example?

I guess not..
But I was measured with AC not DC. I see nothing on DC

6

https://blogs.keysight.com/blogs/tech/bench.entry.html/2018/10/18/when_to_use_ac_coupl-X0K7.html

If you see nothing on DC, maybe your trigger is set below 0V