EEVblog Electronics Community Forum
Products => Test Equipment => Topic started by: cdev on May 31, 2015, 02:10:49 pm
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Although I now have a nice but quite old Tektronix DSO, I have for quite some time been hoping to someday get one of the Bitscope line, just because they seem well made, have a good reputation, and especially, because they take care to release versions of their software for different platforms, making it a lot more flexible. Now they even have ARM versions for Raspbian. Given the ease of powering an RPI from a floating DC supply, this means that you can have a floating oscilloscope that way, which is nice.
Anyway, they are at http://www.bitscope.com (http://www.bitscope.com).
They combine both a 2 channel analog input and an 8 channel logic analyzer.
Perhaps the new Rigol raises the bar quite a bit.. I guess my main question is, which is the better value in your opinion? I already have an HDMI to DVI connector so I can use my RPI with any monitor.
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The BitScope can't be compared to a normal standalone oscilloscope, simply because of its basic specs, which are woefully poor:
http://my.bitscope.com/store/?p=list&a=list&i=cat+0 (http://my.bitscope.com/store/?p=list&a=list&i=cat+0)
40MSa/s is simply inadequate to sample anything more than a 20MHz sine (or maybe a 5MHz square wave, but that's already stretching it) in realtime, and 12k buffer is ludicrously low for a modern scope. Even DSOs from the late 80's had better specs than these BitScopes. Since you mentioned Rigol, even the low-cost DS1000z offers 500MSa/s and 12M memory.
What also rubbed me off a bit was that I had to go to the shopping site to see the basic specs, as they are surprisingly absent from the product page where they just talk about the software.
These BitScopes could be fine for simple automated tasks or low frequency measurements (i.e. audio, although a good soundcard is probably the better option there), or for the education sector, but it's a far cry from a substitute of a standalone scope.
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If you're after a Bitscope unit cheap, I have two for sale here (https://www.eevblog.com/forum/buysellwanted/for-sale-(aus)-bitscope-bs10u-logic-analyser/) and here (https://www.eevblog.com/forum/buysellwanted/for-sale-(aus)-bitscope-bs50-logic-analyser/).
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For the "tl;dr" folks: The BitScope Micro is good hardware for the money, but the software is horrible.
I recently purchased the BS05 ("BitScope Micro") to go with my RasPi2, to be used developing sensors, actuators and nodes for my home automation/security system. Yes, the BS05 specs are minimal (but certainly not trivial), and they do contain a few gotchas (e.g., analog gains are ganged, with no separate per-channel adjustment).
I needed something faster than a multimeter with both analog and logic inputs, and preferably close to the size of a Raspberry Pi (my lab instrument display and server). I surveyed the entire USB MSO market. The competitors included (among others): Saleae, Pico, Link, and Embedded Artists (http://www.embeddedartists.com/products/app/labtool.php). For my immediate needs, the BS05 had the best bang for the buck.
I also liked the good hardware layout and simple packaging: A piece of clear heat-shrink over the entire board that nicely covers everything but the connectors. Tiny and tidy.
Also, being addicted to EEVblog, I liked that the BitScope folks are Aussies in Sydney (though I purchased mine from a US distributor).
However, to my great surprise the software ("BitScope-DSO") is a dog's breakfast. A UI nightmare that takes no clues whatsoever from the success of other MSOs in the market, and blatantly violates every UI interaction metaphor. It is so poorly designed/implemented that it actually hides some of the instrument's capabilities! And changing some settings actively disables or changes other settings, despite the hardware being able to handle all of them without a problem.
Silly, stupid software. It provides the best definition of "counter-intuitive" I've ever seen. It looks and acts more like a piece of early graphical DOS software from the 1980's, as if it were force-fit onto a low-res screen.
The thing I most abhor is that the BitScope folks keep inventing their own acronyms instead of using industry standard terminology, making it a pain to decode the language in their hardware documentation and in the software. And the software insists on using cryptic short abbreviations that must be memorized, and the software totally fails to provide any contextual help and/or hover-text to assist the user in making sense of the gibberish.
The software is also missing some fundamental capabilities most of us would take for granted: It can't save / restore the instrument configuration. It doesn't let you name the signals (so the screen display is easier to map to the project, and to make it easier to resume a prior experiment). The displayed measurements are few in number and are difficult or impossible to configure, with obtusely cryptic 2-letter names. The logic decoder app (for UART/I2C/SPI/CAN decoding) can't run while the MSO app is running. The list of brain farts goes on. And on. And on.
The worst sin of all is that they market this to STUDENTS! It will only serve to needlessly discourage some, and set the rest up for unpleasant surprises when they try to use "real" MSOs.
At one time there were multiple open source efforts to craft a better UI for the BitScope hardware, but all of the projects all seem to have either ended or gone in different directions (to support other hardware instead of BitScope).
Yes, the software does get enough of the job done to permit samples to be captured, displayed and exported for offline use. But it does so in the most awkward and non-obvious way possible.
The BitScope-DSO software isn't all bad (just ugly, needlessly difficult to use, mis-matched to the hardware, and lacking features). It does have the ability to remotely control a BitScope over the Internet (or LAN), which makes the demo truly useful: The BitScope folks have placed an MSO (called "Sydney") online for users to play with! Very kind of them.
So, be sure to try the software FIRST, before buying any BitScope hardware. If you know you can live with it, only then consider placing an order. In my case it would have been a show-stopper, since I would have been gagging too hard to press the "Buy" button. YMMV.
Still, I do love the hardware: A RasPi2 + BS05 makes a capable and inexpensive basic MSO. Connecting it to an HDTV permits the display to be further away from my breadboard, giving me more room to work (and less need to squint).
Attaching a pair of scope probes is a hassle unless you purchase the $30 MP01 "Hammerhead" (http://www.bitscope.com/product/MP01/) accessory. I rolled my own using BNC adapters (http://www.mpja.com/Adaptor-BNC-Female-to-DC-Connector/productinfo/30413%20PL/) with a couple of female-female jumper leads (http://www.mpja.com/40Pc-Header-Female-Female-Jumpers-8in/productinfo/30117%20PL/) cut in half. Combining a couple of 20 MHz probes (http://www.mpja.com/20MHz-Oscilloscope-Probe/productinfo/15085%20TE/) with such light hardware, I was concerned that dropping a probe could pull down everything: This way, it just unplugs itself from the BS05.
Be careful when buying the BNC adapters: Some that look identical to the ones above contain an RF balun for connecting antennas to coax. I verified with MPJA that the above adapter does NOT contain a balun.
Edit: If anyone would like a more detailed BS05 hardware review, let me know.
Dave, would you mind stepping over to the BitScope offices (http://www.bitscope.com/about/) and strangling some sense into their software crew? Or, better yet, ask for a sample unit and do a review!
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I have the little Bitscope. It is no substitute for a real scope, but it can help in a pinch (software is buggy though, I use OS X). I got it for travel, but when I am home I never use it as it's useless next to a real scope.
I would not recommend it for your main scope. Especially considering that you can get a real 2nd hand scope for the price.
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I concur regarding the software. I bought a BS50 quite some years ago, nice idea to have something to travel with, and it was bus powered, only one BNC in but two analogue ins, an LA and an AWG. The concept was awesome, it was really well made. But the software, well, it's all been said.
For an example of how to do software properly, look at the Digilent Analog Explorer Discovery, but I think the GUI's only Windaz. I believe that the API is cross platform, I am sure someone will be able to correct and/or clarify. That device's hardware bandwidth specs are woefully underestimated too, it's way more than the 5MHz or so quoted. I sat on a train yesterday for a couple of hours with one debugging an SMPS, got a couple of funny looks but I wasn't wheeled off by the rozzers for being sober in charge of an oscilloscope. If you have academic credentials there are substantial discounts to be had on it.
Meanwhile, the Bitscope remains in a drawer, as it has done for almost all of its life.
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even the low-cost DS1000z offers 500MSa/s and 12M memory.
1GSa/s...
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I've had a BS325N, which is the LAN interfaced dual input model for 10 years now. At the time it was a pretty good scope for the money, but today I'd just go buy a Rigol DS1000Z (which I have one of also). The software is very sub-par. These days I use it mainly for long-term data capture, but even their SDK is pretty poor compared to an LXI device. The bandwidth is fine, but 40MSa/s and 1M capture isn't a modern spec even for an entry level scope. I agree with all the comments on the software. It is, however, indestructible - could run it over with a bulldozer and all that would happen is it got embedded in the road surface... I do use it as a logic analyzer on occasion as well.
If you can get one for a good price it might be worthwhile, like $100-150. Maybe.
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even the low-cost DS1000z offers 500MSa/s and 12M memory.
1GSa/s...
Yes, but only in single channel mode.
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I wanted an MSO I could stuff in the side of a laptop bag and that didn't need a separate power supply, which to me means a USB MSO. MSOs with a front panel are great at the test bench, but they are a royal pain to drag into the yard to debug a moisture sensor or a sprinkler actuator, or to the driveway to help with a car hack.
Were I in the market again, I'd probably go with the MSO-28 from Link Instruments (http://www.linkinstruments.com/mso28.html). Double the price of the BitScope BS05 (after you add scope probes and adapter to the BS05), but with vastly greater hardware capabilities (2 Gsps) and much clearer software (but Windows-only).
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Bitscope is junk. I had one 4 channel plus the 16 bit logic analyser. I threw it away. Its got no memory , samples very slow , uses two pic processors running some scripting sytstem to change its functionality. The analog fromtend is crap. Comes with 1:100 probes (good luck picking up anything in the sub one vt range
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Were I in the market again, I'd probably go with the MSO-28 from Link Instruments (http://www.linkinstruments.com/mso28.html). Double the price of the BitScope BS05 (after you add scope probes and adapter to the BS05), but with vastly greater hardware capabilities (2 Gsps) and much clearer software (but Windows-only).
The 2GSa/s sample rate is ETS (i.e. repetitive), not real-time (the real-time sampling rate is a lowly 200MSa/s) which is pretty poor compared to a modern DSO, and 1000 points (1M) memory isn't stellar, either.
If you need something portable then you're probably much better off with one of the various handheld DSOs than with these USB scopes.
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If you're after a Bitscope unit cheap, I have two for sale here (https://www.eevblog.com/forum/buysellwanted/for-sale-(aus)-bitscope-bs10u-logic-analyser/) and here (https://www.eevblog.com/forum/buysellwanted/for-sale-(aus)-bitscope-bs50-logic-analyser/).
I guess nobody wants to buy something that the seller can not use either given the poor specs :)
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If you're after a Bitscope unit cheap, I have two for sale here (https://www.eevblog.com/forum/buysellwanted/for-sale-(aus)-bitscope-bs10u-logic-analyser/) and here (https://www.eevblog.com/forum/buysellwanted/for-sale-(aus)-bitscope-bs50-logic-analyser/).
I guess nobody wants to buy something that the seller can not use either given the poor specs :)
2 out of 3 sold. I simply didn't use the older ones due to the software. I don't need the newest one as I have a DS1054Z now. :)