Zaurus Oscilloscope, using commercial hardware Options

[jfr]

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.

Cheers

John

[speculatrix]

cool! excellent work! I assume you're using the qtopia/qt toolkit, did you build the toolkit from scratch or did you find a verson for downloading?

[jfr]

cool! excellent work! I assume you're using the qtopia/qt toolkit, did you build the toolkit from scratch or did you find a verson for downloading?

Well, it's based around the Qt library, but almost all the widgets are hand-crafted (I invented a JWidget base class, which paints itself on a single parent QWidget). The reason was that I couldn't control the QWidget resize behaviour well enough: the widgets on the scope panel have to rearrange themselves in response to a change in the main window size (ie orientation), but when Qt issues the resize event it's already recalculated the window size from the current widget arrangement and I couldn't find a way around the problem. I'm sure it would have been possible with the right insight, but there you go. It did make life easier with the horizontal scroll bar and its drop-down cursors.

Which reminds me to mention that the horizontal scroll bar has a hidden feature. If you drag the thumb, it responds as normal. But if you start the drag in the trough, it gives a finer control. At high magnifications, that means you can still position the waveform accurately.

The project's cross-compiled from a desktop machine, basically using the instructions given at http://www.oesf.org/index.php?title=Compiler_Setup and with the downloads recommended there. I wrote a Tcl script to automate the build and the ipk generation.

I also had to incorporate a fixed-point arithmetic class, because otherwise the display update was much too slow, given the Z's lack of floating point hardware. Got the update time down from 114ms to 27ms that way.

Did you try running the program btw?

[speculatrix]

I also had to incorporate a fixed-point arithmetic class, because otherwise the display update was much too slow, given the Z's lack of floating point hardware. Got the update time down from 114ms to 27ms that way.

Did you try running the program btw?

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are you releasing this work under the GPL or other approved OSS license, and if so, is your friend releasing his work too so that you can release source code?

'fraid I won't get round to running this very soon 'cos I'm running Angstrom with GPE (i.e. GTK/X11), but when qtopia2 or qtopia4 on angstrom makes it to beyond beta then I've love to give it a go building your code for Angstrom!

Paul

[jfr]

are you releasing this work under the GPL or other approved OSS license, and if so, is your friend releasing his work too so that you can release source code?

The Syscomp software that comes with the DSO-101, and from which my port was derived, is released as the Open Instrumentation Project on sourceforge, under the GPL. I plan to contribute my port to that project when it's proven to work well enough, so It'd be under the same licence.