Cheap oscilloscope

crutschow

Joined Mar 14, 2008
34,285
Those aren't oscilloscopes, they are A/D converters.
There's a significant amount of additional circuitry needed to display the digital signal on a display.
Here's an example design.
 

Thread Starter

Motanache

Joined Mar 2, 2015
540
Thanks for link.
A device of that kind I intend to realize.

PIC30F2020 I had it for few years ago and I know how it work.
I'm looking to modify this scheme for better characteristics of the oscilloscope.
 

DickCappels

Joined Aug 21, 2008
10,152
Your choice of Analog to Digital converter will depend upon the uses to which you expect to put your scope, how much you want to learn from the experience, and of course how much you can spend.

For example:

To what use do you plan to put your scope?

Are you interested in writing interpolation routines (to connect the dots)?
 

Thread Starter

Motanache

Joined Mar 2, 2015
540
I want to write code.(ASM+C)

There are some cheap oscilloscope kits:
https://www.aliexpress.com/item/DSO...lectronic-Learning-Kit-Parts/32395194259.html

28$:
Major features of DSO138:

Analog bandwidth: 0 - 200KHz
Sampling rate: 1Msps max
Sensitivity: 10mV/Div - 5V/Div


The price is good since it has a color dispaly.


Something like that I want to do but with a higher bandwidth.

It will be a general purpose device.
With this occasion I will practice programming and math.
I want to use it in the ham radio band 3.5MHz 14MHz and CB27MHz for verification of power stage.
Ideally you can view the signal and 144MHz band, but I realize I can not achieve this without fpga.

It is a hobby device.
 

Thread Starter

Motanache

Joined Mar 2, 2015
540
Red Pitaya apparently is a good oscilloscope.
redpitaya.com/
They said it is open source.
It's quite expensive, but I wanted to make a calculation of the cost components.

But unfortunately I have not yet found a diagram of this oscilloscope.
 

UAX

Joined Jan 10, 2017
8
The DSO138 is actually a incredibly useful (and cheap!) device. Great for analyzing all sorts of basic circuits, as long as you stay within its limits. I can definitely recommend it to anyone and imo it's handier than those cheap chinese USB dso:s. You'll need something much faster, though...
 

MrAl

Joined Jun 17, 2014
11,389
Hi,

To get faster you can use the "F" series TTL logic for the address counters. That can get you up to maybe 100MSPS.
I did this on a scope i was working on back in the mid 1990's when small scopes were very very expensive.
These days you can get a 200MHz/1GSPS scope for 300 dollars (USD) or so. That's less than the cheapest CRT scope you could get back then.

Yeah the little 1MSPS red pc board scopes look cute :)
 
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