USB scope probe - request for comments and ideas

Question

Idea:

Take one oscilloscope probe, and one USB cable. Cut the BNC connector off the oscilloscope probe, and the USB B connector off the USB jack and splice them together.

Mount all the USB <--> analog circuitry inside the scope probe body and/or the USB A connector body. It would essentially compete with all the other USB oscilloscopes out there, but it would be in a single cable design - no extra boxes, etc.

1. Is this a product you would like?
2. What are your minimum specifications for this type of product?
3. What are your ideal specifications for this type of product?
4. Would this be any more useful or desirable than the current USB oscilloscopes available?

My biggest concerns are:

• Obtaining the speed necessary to be reasonably useful without requiring a lot of components
• Synchronizing multiple probes into the computer (Getting nS accuracy without wiring the probes together seems problematic...)
• Fitting it all into the form factor and power limitations of a USB port (ideally 100mA unpowered hub ~0.5W)
• Keeping the assembled cost low

I'd appreciate feedback on any or all of the above (what you want vs how to implement it). Ideally it'd be completely open source, but using very tiny surface mount parts it might not be easily assembled by hand.

Answer 1

I would certainly be interested in this. Particular things that would appeal to me:

1. Isolation from PC and from other channels
2. Multiple synchronised channels
3. Polished cross-platform interface software
4. Cheaper than the competition: the other self-contained units such as the handheld picoscopes.

I've used quite a few USB scopes, but the (single- and dual-channel) picoscopes trump the rest simply on the software at the moment.

To be honest, personally I'm not that bothered by the self-contained thing or the unpowered hub thing. If I could find some good, cost-effective, multi-channel USB scopes that worked on any platform, had good software, reasonable specs and isolation between the channels, I'd be over the moon.

Answer 2

Multiple inputs are pretty important. If you could figure out how to use one probe to trigger the others there would be some good potential. A single probe useful but on a pretty limited basis.

Answer 3

You might also be interested in: Digital Oscilloscope at fpga4fun.

Answer 4

1. Yes
2. 1MHz, 1Msps, completely isolated from my PC's USB port
3. 10Mhz, 10Msps
4. Only if it were a lot cheaper. The DSO nano is $89 and is self-contained.

Answer 5

See this interesting little AtmelTiny45 CPU based scope. This could easily fit in a probe shell and gives basic functionality for a few bucks...