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> Zaurus Oscilloscope, using commercial hardware
post Aug 24 2007, 03:43 PM
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This post is a trawl, to see whether there's any wider interest in an oscilloscope project I've been working on.

The project uses a digital scope manufactured by Syscomp - the DSO-101. It's a two-channel scope, which plugs into a USB port and uses the conputer as its driver and display. You can read lots more about it at Syscomp's web site.

What I've been doing is to port the host software to the Z.

I bought the scope in the first place in connection with a Morse-to-speech project (mentioned before in these forums). I liked the spec and the price, and I particularly liked the fact that the software that runs on the host is open sourced. The software is written in Tcl/Tk, and I've been porting the main functionality to C++/Qt.

The scope hardware is physically bigger than a Zaurus, but not by all that much, so I thought it would be neat to use the Z as a host and thus end up with a pocket-sized oscilloscope system.

I've now got the port working pretty much to my satisfaction (YMMV). The port doesn't have all the advanced features of the original software, but I think it does count as a workable system. My Zauri are still using their original Sharp ROMs, and the program should work on C1000/3000/3100/3200.

(Dis)claimer: When I first bought the scope, I was merely another customer for Syscomp. I then offered them a couple of contributions for the host software, and that progressed to the point where I became a beta-tester for them. From that, I discussed the idea of the Z port and they were immensely supportive, including supplying extra hardware for the purpose. From that, you'll correctly gather that I think these people are Good Guys. But I have no commercial relationship with them - this is an open source project, pure and simple.

Maybe this is just my private toy, but if anyone else would be interested, I'd be happy to share it.


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post Aug 31 2007, 10:01 AM
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Hum ... I think it's more commonly known as "Shannon sampling theorem".
Anyway since xoscope does not use any additional hardware it's limited by two factors:
1) the Shannon sampling theorem"
2) the bandpas filters in the input circuitary sound hardware (wich must have a high cut off frequench <= 1/2 sampling freq or the ADC would start pproducing odd informations and any fast furier trasformation on the digital signal thus produced would be hevily distorted)
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post Aug 31 2007, 12:01 PM
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hmm, it's been a long time since I did analogue and digital comms at university! I recall Nyquist being the stuff about sampling rate being double the max frequency to avoid aliassing, and Shannon being about information rate... but it looks as if it's all counted together now:

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post Sep 1 2007, 06:44 AM
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Ok, here's some further info on the project. On my minimalist web site there's now a page with screen shots and description of the work so far.

There's also an ipk file, for any brave souls who would like to see whether the program runs on their machine. If you try it, take a backup first - this needs to be treated as untrusted software which could crash and burn. It should run on C1000, C3000, C3100 and C3200 but I've been testing it only on a stock C3000.

Running the program without a scope connected to it won't be a terribly rewarding process, but you should be able to operate the controls and generally inspect the GUI.

For anyone who might already have a DSO-101, you'll also need to change the permissions on /dev/ttyUSB* to allow read/write access for all users.

Feedback (positive or negative) would be very welcome.


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Posts in this topic
jfr   Zaurus Oscilloscope   Aug 24 2007, 03:43 PM
gsgmx   Sounds great, i might get one of these scopes too...   Aug 25 2007, 03:42 AM
jfr   QUOTE(gsgmx @ Aug 25 2007, 12:42 PM)The DSO i...   Aug 25 2007, 04:55 AM
Drake01   QUOTE(jfr @ Aug 25 2007, 07:55 AM)It does nee...   Aug 25 2007, 07:24 AM
jfr   QUOTE(Drake01 @ Aug 25 2007, 04:24 PM)Sounds ...   Aug 25 2007, 03:55 PM
Drake01   QUOTE(jfr @ Aug 25 2007, 06:55 PM)Thanks, Dra...   Aug 26 2007, 07:45 AM
pelrun   Wow, I think I need to start putting away some pen...   Aug 25 2007, 08:57 AM
aeazocar   jfr, Congratulations, this is a great project...   Aug 26 2007, 06:28 AM
boardboyd   Just to add, I'm in support of this project an...   Aug 28 2007, 08:43 AM
speculatrix   am definitely interested... in fact I talked to a ...   Aug 28 2007, 02:17 PM
jfr   QUOTE(speculatrix @ Aug 28 2007, 11:17 PM)am ...   Aug 28 2007, 03:46 PM
speculatrix   definitely very interested, whether the source was...   Aug 30 2007, 01:55 PM
Da_Blitz   mm, cant believe i missed this post, i am thinking...   Aug 31 2007, 01:53 AM
louigi600   I've been using on my x86 pc (with linux natur...   Aug 31 2007, 04:31 AM
Da_Blitz   xoscope is nice but it has its limits, mainly bien...   Aug 31 2007, 05:13 AM
speculatrix   QUOTE(Da_Blitz @ Aug 31 2007, 02:13 PM)xoscop...   Aug 31 2007, 08:20 AM
louigi600   A free audible band oscilloscope/spectrom analizer...   Aug 31 2007, 06:18 AM
louigi600   Hum ... I think it's more commonly known as ...   Aug 31 2007, 10:01 AM
speculatrix   hmm, it's been a long time since I did analogu...   Aug 31 2007, 12:01 PM
jfr   Ok, here's some further info on the project. O...   Sep 1 2007, 06:44 AM
Da_Blitz   not to mention the low freq cutoff is normally fai...   Aug 31 2007, 10:26 AM
speculatrix   cool! excellent work! I assume you're ...   Sep 1 2007, 01:14 PM
jfr   QUOTE(speculatrix @ Sep 1 2007, 10:14 PM)cool...   Sep 1 2007, 02:36 PM
speculatrix   QUOTE(jfr @ Sep 1 2007, 11:36 PM)I also had t...   Sep 1 2007, 02:56 PM
jfr   QUOTE(speculatrix @ Sep 1 2007, 11:56 PM)are ...   Sep 1 2007, 03:24 PM
speculatrix   I am wondering if anyone's done anything new f...   May 13 2008, 01:04 PM
Ragnorok   - Neat! I've been looking for a DSO to do...   Jun 29 2008, 04:10 PM
jfr   QUOTE(Ragnorok @ Jun 30 2008, 01:10 AM) 1...   Jul 20 2008, 02:39 PM
pelrun   Well the syscomp features adjustable pre and post ...   Jun 29 2008, 05:00 PM
Ragnorok   - Sorry for my slow reply. I have seventy differe...   Aug 28 2008, 10:36 AM

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