Are low/lower cost USB Oscilloscope's any good?
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From: joseph2k on 17 Dec 2006 07:28 Charlie Edmondson wrote: > bill.sloman(a)ieee.org wrote: > >> Charlie Edmondson wrote: >> >>>Joerg wrote: >>> >>> >>>>PeteS wrote: >>>> >>>> >>>>>Joerg wrote: >>>>> >>>>> >>>>>>Hal Murray wrote: >>>>>> >>>>>> >>>>>>>>I've been impressed with these guys: http://www.cleverscope.com/ -- >>>>>>>>they seem to have a solid understanding of what terms like "noise" >>>>>>>>and "jitter" mean, unlike many of the cheap scopes out there. >>>>>>> >>>>>>> <snip> >> >> Wherever I've worked, rule one has always been, don't develop anything >> you can buy. Academics do have delusions about developing stuff in no >> time with no bugs, but university workshops know better. >> > Well, I have also seen the same sort of thing on the commercial side, > too, where a boss didn't want to upset the budget apple cart to get > something he felt the 'boys' should be able to just whip up out of teh > parts room... > > Charlie Bog, reminds me of when my boss wanted me to build a digitizing 'scope. It was about the time the early 6-bit and 8-bit flash converters first hit the market. Doing the design was not the problem, i even could get the parts i wanted; getting the hours to actually build it was. It turned out, of the available personnel only i had the necessary combination of expertise to do the various tasks required to build a useful unit. (yes i was both tech and engineer) and management decided that my time was too valuable elsewhere to complete the project. You are invited to design working pre-trigger recording at near logic limit speed as well. (at the time 20 MSPS, today, about 6 GSPS) -- JosephKK Gegen dummheit kampfen die Gotter Selbst, vergebens. --Schiller
From: Charlie Edmondson on 18 Dec 2006 17:04
joseph2k wrote: > Charlie Edmondson wrote: > > >>bill.sloman(a)ieee.org wrote: >> >> >>>Charlie Edmondson wrote: >>> >>> >>>>Joerg wrote: >>>> >>>> >>>> >>>>>PeteS wrote: >>>>> >>>>> >>>>> >>>>>>Joerg wrote: >>>>>> >>>>>> >>>>>> >>>>>>>Hal Murray wrote: >>>>>>> >>>>>>> >>>>>>> >>>>>>>>>I've been impressed with these guys: http://www.cleverscope.com/ -- >>>>>>>>>they seem to have a solid understanding of what terms like "noise" >>>>>>>>>and "jitter" mean, unlike many of the cheap scopes out there. >>>>>>>> >>>>>>>> > > <snip> > >>>Wherever I've worked, rule one has always been, don't develop anything >>>you can buy. Academics do have delusions about developing stuff in no >>>time with no bugs, but university workshops know better. >>> >> >>Well, I have also seen the same sort of thing on the commercial side, >>too, where a boss didn't want to upset the budget apple cart to get >>something he felt the 'boys' should be able to just whip up out of teh >>parts room... >> >>Charlie > > > Bog, reminds me of when my boss wanted me to build a digitizing 'scope. It > was about the time the early 6-bit and 8-bit flash converters first hit the > market. Doing the design was not the problem, i even could get the parts i > wanted; getting the hours to actually build it was. It turned out, of the > available personnel only i had the necessary combination of expertise to do > the various tasks required to build a useful unit. (yes i was both tech and > engineer) and management decided that my time was too valuable elsewhere to > complete the project. You are invited to design working pre-trigger > recording at near logic limit speed as well. (at the time 20 MSPS, today, > about 6 GSPS) > And, sometimes it gets built in house due to politics... I was working on toll roads, and we needed a 'presence' detector, i.e. Is there a car there, or not? We had a great laser sensor from a manufacturer ($10K per unit...) but only covered about 3 feet. We needed to cover 12 feet of lane, three lanes wide, so this would use 12 units. BUT, this was to replace the only commercial unit they had found that was $100 PER LANE, so management wanted to see if we could do it. Now, the obvious solution would be to just hook up all four sensors (they connected with just two wires for sensor line a and b) to the lane control computers, and do the combination in software. However, the lane control computers were with a different branch of the company, and their software 'assumed' they would just get a single line saying car present, or not. So, they were going to just put out the $300K for the commercial units. So, I went to the boss, and said that I could put together a simple interface and logic board to interface with the units, and save us $150K. So, in this case, I volunteered for the job. He gave me 6 weeks to get a prototype out. I also suggested that I could add some intelligence by using programmable logic (an eprom state machine) but that would take a little longer. He gave me an additional 4 weeks to add the programmability. I designed and built the prototype in four weeks. It was tested and heading out to the test track in 6 weeks... with three different programmable state machines! Charlie |