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smadge1

555s and LM358s - DSO138

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Hi folks

 

I built myself a DSO138 kit recently, with the intention of learning how to oscilloscope!

 

I have a bunch of various "frequency generator" modules from eBay. Some are based on the 555 timer, and some are based on the LM358 Op-Amp.

 

I thought I had the 555 figured out, it uses external components and internal logic gates to switch an output pin on or off. The timing is based on the values of the external resistors and capacitors.

 

I'm not sure how the LM358 accomplishes the same thing, but I assume it's used as a comparator, similar to the 555, using similar external components.

 

https://twitter.com/smadge1/status/677072320117141504

CWVxqqHUYAEPOnU.jpg

 

I have this setup at the moment, connected the DSO138 to the output pin of the LM358. I have removed all the jumpers, these add extra capacitors into the circuit. The two trimpots adjust the frequency and the duty cycle of the square wave.

 

 

https://twitter.com/smadge1/status/677078367812775936

CWV3KB2UkAA8a3Z.jpg

 

 

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It is looking really very interesting to build an Oscillioscope.
I also want to build the same.
Can you please help me how i could start?
What components are required for this?
Which MCU you are using here?

 

passive components

Edited by DagArenas

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It is looking really very interesting to build an Oscillioscope.

I also want to build the same.

Can you please help me how i could start?

What components are required for this?

Which MCU you are using here?

 

it's a partly pre-assembled kit (ie, the SMD are already on the board), The MCU is a STM32F103C8

 

Check these sites:

JYETech Link: http://www.jyetech.c...dScope/e138.php

or

SainSmart link: http://www.sainsmart...msps-probe.html

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