Saleae Logic Analyser.

[bigandy]

Morning all.

I've decided that my Rigol DS1022CD Oscilloscope with logic analyser head is a little bit clunky for use decoding and monitoring communications protocols (like I2C, RS232 etc), and I think I am going to treat myself to a dedicated Logic analyser that is able to monitor communications and present them in a clear to understand way.

I've seen the salae "logic" device mentioned in a couple of threads, and looking at the website (http://www.saleae.com/logic/) it does seem to do everything I want. The main thing is that it comes with an I2c, rs232 and SPI protocol analyser built in, and also has an SDK available for developing further tools if I ever feel the need to. Looking at the website, it does seem to be well supported and documented, so the possibility of other features being added to the software are looking quite good too.

I was wondering if anyone here has one of these devices, or has tried one out at all? I'm just looking for some real world feedback on whether it is worth the money, or not? Are there any major gripes with the unit that should have me considering other devices?

Your thoughts would be much appreciate, cheers!
Andy

PS. just downloaded the demo software for a test drive :)

[bigandy]

First impressions of the PC software are that it is nice and clearly laid out, almost intuitive in fact! It seems you can assign up to 4 analysers to the 8 inputs (and choose from asynchronous serial, I2c, SPI and 1-wire protocols) at any one time, and where possible, those protocols can be tweaked for the exact settings you are looking at (such as data bits per word etc).

The display options for the captured data is also quite useful, being able to view the data in ASCII, HEX, Octal or decimal, live on the screen. The export options also look quite useful, with several options available (inc binary and CSV output).

I have just noticed one potential limitation, and that is the 24MHz maximum sample rate. It would be nice to have something that could cope with a bit more speed, but for 99% of the stuff I envisage using this for, it should be okay. Or should it?

€129 does seem quite tempting though :)

Andy

[13brv3]

I have one of the Saleae Logic analyzers, and it's just an outstanding device. It's one of my favorite bits of test gear now. If you want to play with some real I2C data, drop me an email and I'll send you some from a Mikrokopter.

Cheers,
Rusty

[Mark_O]

bigandy,

you might want to browse through this thread (http://www.rcgroups.com/forums/showthread.php?t=1023934) on USB-based logic analyzers and serial protocol analyzers. There's some discussion there of the Saleae's pro's and con's, which is a fairly nice unit, and some other alternatives.

- Mark

[bigandy]

Thanks for that link Mark, I've had a good read through of it. By the sounds of it, and now that I have seen the usbee sx device, that might be a better bit of hardware to go for. The main plus point is the fact that it can be used as a signal generator to play back captured data, which I can see being immensely useful for me!

Apart from that, it seems to do everything that the Logic unit can do, which is good....

hmmmm what would you buy?!

Andy

[bigandy]

I've looked at the manuals in a bit more detail, and it looks like you can create custom decoding routines too, which is another plus point towards the usbeesx.....

Andy

[Mark_O]

Andy asked:
> ...hmmmm what would you buy?! <

Well, both are good options, but I wound up buying the USBee SX unit. For the reasons why, and a bit more direct comparison, I've gone ahead and posted my additional comments in the above referenced thread, here (http://www.rcgroups.com/forums/showpost.php?p=12719278&postcount=54). Cheers!

- Mark

[bigandy]

That's a really useful post, cheers Mark! I've replied over there too, but at the moment I am leaning towards the USBee SX unit. The output ability is swinging it for me :)

Andy

[JimDrew]

With the Saleae product I was able to completely reverse engineer the Eagletree system so that we could make a telemetry sensor for our radio system. It is an outstanding piece of hardware and software, but I too, wish it has the ability to output data. The designer is beta testing all new firmware/PC software that is suppose to have this capability. I do not know how far along that project is.

[bigandy]

I've actually just had an email back from the chap(s) at Saleae, as I sent them an email asking a few questions about the Logic unit's capabilities. One of them questions was regarding the potential for turning it into a logic signal generator. I was told that it is certainly possible, and it is available in the current SDK beta, but is lacking the nice front end software to drive it. I was told it may be some time before that functionality is available for "end" users like myself (i.e. those that don't want to dabble with the SDK). I was actually recommended the USBee SX by them if that was a requirement of mine. That sort of attitude is really refreshing!

I'm going to buy one of the USBee SX units anyway. That does everything I would like in the short term. If (when) the saleae unit has the output capability, I'll probably test drive one, and see which I like the best :)

Cheers for the input folks, much appreciated!

Andy