PC Oscilloscope ... getting better

Hi all, a few months ago I started to design and build my own oscilloscope...and in this groups I had a lot of help in solving some problem...

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I'm getting so excited now... and surprise at same time... how things are getting better and better. The oscilloscope is now very useful indeed, I have added the capability to see the spectrum, and it works really well.

I still have a long way to go... but it looks promising. please see the picture on my blog.

I'm starting thinking at the next prototype now... shall I go for a 200 MHz + 64 KRAM ( which I can put on the market for less that 200 pounds cheap oscilloscope but does what it says...) or shall I prototype a 1GSPS? and have a larger margin? Any suggestions is welcome.

Thanks, Francesco

Reply to
Francesco Poderico
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On a sunny day (Sun, 31 Mar 2013 13:52:24 -0700 (PDT)) it happened Francesco Poderico wrote in :

this groups I had a lot of help in solving some

getting better and better.

the spectrum, and it works really well.

on my blog.

that 200 pounds cheap oscilloscope but does what it

Did you add tegh TV part?

Reply to
Jan Panteltje

in this groups I had a lot of help in solving some problem...

getting better and better.

o see the spectrum, and it works really well.

icture on my blog.

less that 200 pounds cheap oscilloscope but does what it says...) or shall I prototype a 1GSPS? and have a larger margin?

You are doing great work!

Reply to
brent

this groups I had a lot of help in solving some

getting better and better.

the spectrum, and it works really well.

picture on my blog.

that 200 pounds cheap oscilloscope but does what it

Nice.

Hey Jan,

Looks like you need to get a bigger PIC! :)

--

John Devereux
Reply to
John Devereux

On a sunny day (Mon, 01 Apr 2013 11:17:41 +0100) it happened John Devereux wrote in :

this groups I had a lot of help in solving some

getting better and better.

see the spectrum, and it works really well.

picture on my blog.

that 200 pounds cheap oscilloscope but does what

Who knows: PIC scope with FFT: http://127.0.0.1/panteltje/pic/scope_pic/index.html

I do not even need a micro-processor for TV: http://127.0.0.1/panteltje/scope_tv/index.html

Just wrote a GPS NMEA parser in PIC 18F asm in 5726 bytes,, position, speed, heading, altitude.

And I did that with the PIC, programmer, and GPS in a different place, all remote via ssh -Y from the laptop. Zero crashes, else I would have had to go there to power cycle....

So proud of myself, can still do it :-)

root@raspberrypi:~/compile/pantel/gps_pic# jppp18pi -i gps.hex -e -p -Y Loading hex file: Program 5726 bytes at address 0x000000 ID 0 bytes at address 0x200000 Config 14 bytes at address 0x300000 EEPROM 0 bytes at address 0xf00000 Erasing chip. Writing program space. Writing config space. Verifying program space. Verifying config space. Ready.

Your turn

Reply to
Jan Panteltje

Corrected links, sorry, gave localhost... :-)

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Reply to
Jan Panteltje

OK, one more time:

PIC scope with FFT:

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I do not even need a micro-processor for TV:

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Reply to
Jan Panteltje

d in this groups I had a lot of help in solving some problem...

re getting better and better.

to see the spectrum, and it works really well.

picture on my blog.

or less that 200 pounds cheap oscilloscope but does what it says...) or sha ll I prototype a 1GSPS? and have a larger margin?

Thanks, now works at 200 MSPS! :-)

Reply to
Francesco Poderico

this groups I had a lot of help in solving some

getting better and better.

see the spectrum, and it works really well.

picture on my blog.

that 200 pounds cheap oscilloscope but does what

Yes, yes, nice... but Francesco is already doing 100MSPS and making good progress towards more it looks like.

I remember doing that, sort of, when I was a teenager with my first scope. Not very good though, did not know how to do the syncs properly, had to just adjust the frequency and hope it locked somehow.

Was still cool to see!

[...]

The only thing comparable to your scope recently was a lashed-up 120MHz STM32F205 microcontroller running a 2MHz 12 bit external ADC.

During testing I captured the sample buffer with gdb, dumped it through a little python script I found that fed it into gnuplot. Ended up with some really nice, true 12 bit high-resolution plots of various waveforms. Could make a beautiful low frequency scope like that, maybe with a really high resolution screen like the high end ultrabooks use. Job for my pi perhaps?

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John Devereux
Reply to
John Devereux

On a sunny day (Mon, 01 Apr 2013 13:37:32 +0100) it happened John Devereux wrote in :

Cool, yes it has plenty of memory to store waveforms, There is also 'risc OS' for it, I have it, but really had no time to delve into it,

Reply to
Jan Panteltje

this groups I had a lot of help in solving some problem...

getting better and better.

the spectrum, and it works really well.

picture on my blog.

that 200 pounds cheap oscilloscope but does what it says...) or shall I prototype a 1GSPS? and have a larger margin?

You seem to be doing good work. Is your spec of 5 mV/div really valid? That would be pretty nice. Most of the low cost scopes don't do so well on sensitivity.

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Rick
Reply to
rickman

in this groups I had a lot of help in solving some problem...

are getting better and better.

to see the spectrum, and it works really well.

picture on my blog.

less that 200 pounds cheap oscilloscope but does what it says...) or shall I prototype a 1GSPS? and have a larger margin?

Maybe 500Ms/s and 1 Ms ram. Really long record lengths have some specific usefulness.

?-)

Reply to
josephkk

this groups I had a lot of help in solving some problem...

getting better and better.

see the spectrum, and it works really well.

picture on my blog.

that 200 pounds cheap oscilloscope but does what it says...) or shall I prototype a 1GSPS? and have a larger margin?

Can you even buy 64 kword RAMs these days? A 32 MB SDRAM chip will do all that is needed I believe. Either run it at 100 MHz with twice the width of the storage needed or I expect it won't be hard to find SDRAM that can be clocked at 200 MHz. This wouldn't add much to the cost of the device, but would greatly improve functionality.

--

Rick
Reply to
rickman

oscilloscope...and in this groups I had a lot of help in solving some problem...

are getting better and better.

capability to see the spectrum, and it works really well.

the picture on my blog.

for less that 200 pounds cheap oscilloscope but does what it says...) or shall I prototype a 1GSPS? and have a larger margin?

specific

The 64k is a ram block inside the FPGA. Completely different situation.

?-)

Reply to
josephkk

less that 200 pounds cheap oscilloscope but does what it says...) or shall I prototype a 1GSPS? and have a larger margin?

Of course... I'm used to using the poor stepchild end of the FPGA families with only a few kB of RAM. Still, I think a RAM chip should be on the board. It seems silly to hobble what seems to be a good design. I know the extra storage would help the work I do.

I think I've offered my help before, but I'll make the same offer. I have some experience with memory interfaces.

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Rick
Reply to
rickman

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