Oscilloscope Wave for PWM Signal

Thread Starter

Lesliev

Joined Jan 13, 2021
9
Hello, I am new to this forum and still learning about some aspects of electronics. I have purchased and installed a USB oscilloscope and am trying to learn how to use it one step at a time. I have set up an Arduino Uno with a PWM sketch to cause an LED to pulse. That part works just fine. However when I connect my Oscilloscope I get a wave form like the one shown in the attached file. As a complete newbie to the oscilloscope I am trying to understand why I am not getting the square waveform I was expecting. I dont know if it is the oscilloscope, its settings or the Arduino setup I am using which is pretty much a very standard setting as is using the basic Fade sketch available in the Arduino GUI I am using.
Sure hope someone can help as I have tried everything and just keeping get ting further lost
 

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Thread Starter

Lesliev

Joined Jan 13, 2021
9
OK after posting I then ran through my very simple setup again and found I was not connecting the probe correctly. Obviously something I should have done before posting a request for help so my apologies for a pointless post. Now, with the correct connections and input from hexreader I am seeing a square wave as expected and now just have to work out how to adjust the Oscope to get a clean wave.
Sure is lots to learn with the Oscope but a great deal of enjoyment doing it.
 

dl324

Joined Mar 30, 2015
12,466
Welcome to AAC!

Now, with the correct connections I am seeing a square wave as expected and now just have to work out how to adjust the Oscope to get a clean wave.
Show us the wave form and settings for vertical amplifier and timebase.
 

Thread Starter

Lesliev

Joined Jan 13, 2021
9
You guys and gals are incredible. So much help and so helpful.
I have attached the latest screen shot of the Oscope and any advice would be so welcome. I do live in Australia and I believe that we do use 50Hz power her but to pick up on that is amazing. As I said you guys and gals are amazing.

Should I post full image or thumbnail??
Waveform-2.jpg
 
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