Why pay for a scoppy?


Author Message
matherp
Guru

Joined: 11/12/2012
Location: United Kingdom
Posts: 9171
Posted: 10:48am 25 Oct 2024      

Specially for Harm  
Coming in RC10 I've unlocked the ADC speed and it can now sample up to CPU speed/96
So in the example below on a RP2040 I'm running the CPU at 378MHz and sampling two channels each at 1.96775 MHz to give a total sample rate of over 3.9MHz

https://youtu.be/7w7MKo9nofo





CLS
FRAMEBUFFER create
FRAMEBUFFER write f
Dim float a(1279),b(1279),aa(639),bb(639),c(639),d(639),e(639)
ADC open 1968750,2,done
For i=0 To 639:e(i)=i:Next
Do
ADC start a(),b()
Do
Loop Until f%=1
f%=0
p%=Math(crossing a(),1.5,-1)
Memory copy float Peek(varaddr a(p%)),Peek(varaddr aa(0)),640
Memory copy float Peek(varaddr b(p%)),Peek(varaddr bb(0)),640
Math scale aa(),50,aa()
Math scale bb(),50,bb()
Math add aa(),50,aa()
Math add bb(),250,bb()
Line graph e(),c(),0
Line graph e(),d(),0
Line graph e(),aa(),RGB(green)
Line graph e(),bb(),RGB(cyan)
FRAMEBUFFER copy f,n
Math scale aa(),1,c()
Math scale bb(),1,d()
Loop
Sub done
f%=1
End Sub


Volhout
Guru

Joined: 05/03/2018
Location: Netherlands
Posts: 4270
Posted: 11:02am 25 Oct 2024      

Hi Peter,

Looking at the saw-tooth waveform it looks like the ADC silicon problem amplifies when you sample faster. Thanks for providing the option.

About Scoppy. You could build a system with an additional build in Pico-W (if you can spare the extra 100mA) that is always available. For diagnosis you would only bring your phone to the site, and connect to the pico-w and diagnose. Even if the system is on top of a mast. Sounds like a solution for some projects. Maybe it is not if you think about it deeper. IS this a solution looking for a problem..? Maybe..

Volhout

PhenixRising
Guru

Joined: 07/11/2023
Location: United Kingdom
Posts: 883
Posted: 12:08pm 25 Oct 2024      

  matherp said  Specially for Harm  
Coming in RC10 I've unlocked the ADC speed and it can now sample up to CPU speed/96
So in the example below on a RP2040 I'm running the CPU at 378MHz and sampling two channels each at 1.96775 MHz to give a total sample rate of over 3.9MHz


Outstanding  

Pluto
Guru

Joined: 09/06/2017
Location: Finland
Posts: 361
Posted: 07:08pm 25 Oct 2024      


Volhout
Guru

Joined: 05/03/2018
Location: Netherlands
Posts: 4270
Posted: 07:45pm 25 Oct 2024      

Hi Peter,

I tried the Scoppy app, and it works really decent. You cannot compare it to a genuine oscilloscope, but for diagnose it is perfect. The default is still 500kHz, but you can configure it different. The Pico-W has a build in (square wave) generator, and 8 channel logic analyzer as well. All in all a decent tool, waiting for some analog interfaces.

I gladly payed the 3 euro's (one time fee) to get the full functionality.

Volhout
Edited 2024-10-26 05:47 by Volhout

PhenixRising
Guru

Joined: 07/11/2023
Location: United Kingdom
Posts: 883
Posted: 08:12pm 25 Oct 2024      

@Volhout

Thanks, Harm. I'm excited about this