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

[louigi600]

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)

[speculatrix]

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:

http://en.wikipedia.org/wiki/Nyquist%E2%80...ampling_theorem

[jfr]

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.

Cheers

John