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

[gsgmx]

Sounds great,

i might get one of these scopes too. My Z is runnin g Cacko 1.23 now so your hostsw should run now. But i am planning to switch to pdaXii13. Qt apps do run there too, i am not shure whether or not.

The DSO is described as USB Host powered, so does it run direct from the 100mA the Z can supply or does it need more mAmps? So it needs a powered USB hub?

Thks, George

[jfr]

The DSO is described as USB Host powered, so does it run direct from the 100mA the Z can supply or does it need more mAmps?  So it needs a powered USB hub?

It does need a powered hub - the scope draws (I think) about 400mA. Also, the scope spec says it needs USB2, but I've found that the Z's USB1 port does drive it acceptably enough. There's an occasional problem in high-resolution mode (where you can capture 32k samples per channel and then examine the waveform in detail), in that sometimes some sample data will be lost. I haven't tracked that down fully, but I believe it's due to the USB1 issue and I haven't found it to be a significant drawback. My software doesn't flag it up when it happens, but it could easily be made to do so.

Cheers

John

[Drake01]

It does need a powered hub - the scope draws (I think) about 400mA. Also, the scope spec says it needs USB2, but I've found that the Z's USB1 port does drive it acceptably enough. There's an occasional problem in high-resolution mode (where you can capture 32k samples per channel and then examine the waveform in detail), in that sometimes some sample data will be lost. I haven't tracked that down fully, but I believe it's due to the USB1 issue and I haven't found it to be a significant drawback. My software doesn't flag it up when it happens, but it could easily be made to do so.

Cheers

John

Sounds like a very cool project. I'd also to point out that the Z does have a USB 2.0 port. The USB 2.0 standard can operate at different speeds. (Decided to actually check Wikipedia to get my facts straight) "High speed" is 480Mbps, "Full speed" is 12Mbps, and "Low speed" is 1.5 Mbps. The Zaurus does not run at High speed, but supposedly it supports the rest of the 2.0 protocol.

Out of curiosity, have you run this on a desktop PC? How does it perform on a PC? And this generally works well on a Z?

[jfr]

Sounds like a very cool project.  I'd also to point out that the Z does have a USB 2.0 port.  The USB 2.0 standard can operate at different speeds.  (Decided to actually check Wikipedia to get my facts straight)  "High speed" is 480Mbps, "Full speed" is 12Mbps, and "Low speed" is 1.5 Mbps.  The Zaurus does not run at High speed, but supposedly it supports the rest of the 2.0 protocol.

Out of curiosity, have you run this on a desktop PC?  How does it perform on a PC?  And this generally works well on a Z?

Thanks, Drake01 - I really had thought it was USB1, and I admit I'm still not quite convinced. The output of lsusb -v on my C3000 begins:
Bus 001 Device 001: ID 0000:0000
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 1.10

I thought the last line there was the USB version number, and hence my comment. But I admit to not having checked further, and I'd certainly welcome a reference where I could learn more. I haven't yet plucked up the courage to go and read the full standard...

Desktop PC: the original Tcl/Tk software runs fine on a desktop (Linux, Mac or Windows, though I've only run it under Linux). I haven't gone so far as to try the port on a desktop - if that's what you meant - some of the code assumes it's on a Z, and I wasn't aiming for anything other than a Z port.

Cheers

John

[Drake01]

Thanks, Drake01 - I really had thought it was USB1, and I admit I'm still not quite convinced. The output of lsusb -v on my C3000 begins:
Bus 001 Device 001: ID 0000:0000 
Device Descriptor:
  bLength                18
  bDescriptorType        1
  bcdUSB              1.10

I thought the last line there was the USB version number, and hence my comment. But I admit to not having checked further, and I'd certainly welcome a reference where I could learn more. I haven't yet plucked up the courage to go and read the full standard...

That's interesting. I had never actually checked that before. The documentation I've read on the Wiki's all states that it's USB 2.0, but not running at high speed. This output seems to imply something else.