Author Topic: DSLogic  (Read 26953 times)

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Offline eev_makr

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Re: DSLogic
« Reply #25 on: January 09, 2014, 05:25:40 am »
guys, all I can say for now: be prepared for another kickstarter launch in 10 days from now, which will solve your questions in a more professional approach, offers more and... comes even at a lower cost (especially for the 100 early birds)

by makers for makers; as a true kickstarter should be
 

Offline BloodyCactus

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Re: DSLogic
« Reply #26 on: January 11, 2014, 05:32:53 am »
I'm in, just so I can replace my open bench logic sniffer. looks like they should hit their second goal and upgrade the memory from 64mbits to 256mbits which will make it a really nice replacement for the OLS
 

Offline electronic_eel

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Re: DSLogic
« Reply #27 on: January 11, 2014, 05:40:10 am »
Hi,

could anybody enlighten me about the specs of the logic analyzer:

In their Spartan6 strech goal announcement they claim 400MHz @ 4 channels. This matches the 1600Mbps Bandwidth they write about.

But below, under "Interface for logic analyzer" they have:
CH15 ~ CH0: 
Maximum Input Bandwidth: 50MHz
CLK, TI, TO:
Maximum state clock: 50MHz

Now how does this fit together? I want to sample fast serial signals, so I'm interested in the 400MHz @ 4 channels they claim. Don't care about the scope stuff, I have a decent scope.
 

Online Marco

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Re: DSLogic
« Reply #28 on: January 11, 2014, 07:10:54 am »
Lets say a 1 feet ribbon cable and lets be optimistic and posit 10 pF capacitance ... at 400 MHz a non active 1x probe with such a cable would load your circuit with <40 Ohm capacitive impedance. At these speeds you really need either active probes or attenuated probes and thus an input stage capable of distinguishing attenuated logic levels.
« Last Edit: January 11, 2014, 07:13:33 am by Marco »
 

Offline electronic_eel

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Re: DSLogic
« Reply #29 on: January 11, 2014, 08:02:18 am »
I see. Thanks Marco.

Why do they then go the FPGA&Mem route? Why not just take a FX3 and let the PC do all the heavy lifting?
 

Online Marco

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Re: DSLogic
« Reply #30 on: January 11, 2014, 08:44:05 am »
Dunno, but that question is relevant regardless ... even your 4x400 Mbps could easily fit across USB 3.0.
 

Offline rrpilot

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Re: DSLogic
« Reply #31 on: January 11, 2014, 08:58:22 am »
I see. Thanks Marco.

Why do they then go the FPGA&Mem route? Why not just take a FX3 and let the PC do all the heavy lifting?

I don't think this product is designed to feed the data to your PC in real time. Basically it's going to trigger, start recording, fill up memory and then slowly (in relative terms) transfer the data to the PC. This is how other high-sample rate logic analyzers function. I worked with one from Agilent that used Firewire and it worked in the same fashion. Since they mention using USB 2.0, there's no way the PC interface could handle the data.
 

Offline electronic_eel

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Re: DSLogic
« Reply #32 on: January 11, 2014, 09:51:00 am »
Yeah, this is what I was talking about. They trigger & record till the mem is full. And then they transfer over usb 2. So all trigger logic has to be inside the FPGA. If you wanted real protocol triggers (which they don't have and don't claim, but are extremely useful), you'd have to code that up in VHDL and try to fit it in the FPGA.

That is why I think using an FX3 and USB 3 would so be much better: the la could be stupid and just transfer all data in realtime to the pc. Using a decent processor for compression, enough ram and a big ssd you could sample all day. A regular pc software, which is easier to write than VHDL and more versatile, could then search for the data you are looking for. No need for intelligent triggers at all.

This is what makes the saleae so simple and still very useful. Using the FX3 would just take it to a new level.
 

Offline dunkemhigh

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Re: DSLogic
« Reply #33 on: January 12, 2014, 01:25:53 am »
Quote
This is what makes the saleae so simple

The Saleae is overly simple: triggering is on levels and an edge only - no protocol stuff, no sequencing, nothing else. Years ago, when it first came out and I bought one, I asked for the triggering to be auto-armed after capture (so you didn't need to keep hitting the capture button), but it's never shown up. You could do the fancy PC stuff in a 74 series logic chip so far as i can see.

And... if the answer is a PC and the stumbling block the LA->PC link, why not do away with the link and shove a PC right there in the LA? A RPi would fit OK, wouldn't it? Do whatever the hell you want and dribble the result out via a web page if you wanted to be perverse, but that web page could be fronting serious real-time cleverness. More likely, you'd dribble the result over a slow bus to some PC GUI app, and that would be the slow and simple thing it should rightly be.
 

Online Kean

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Re: DSLogic
« Reply #34 on: January 12, 2014, 01:38:59 am »
And... if the answer is a PC and the stumbling block the LA->PC link, why not do away with the link and shove a PC right there in the LA? A RPi would fit OK, wouldn't it? Do whatever the hell you want and dribble the result out via a web page if you wanted to be perverse, but that web page could be fronting serious real-time cleverness. More likely, you'd dribble the result over a slow bus to some PC GUI app, and that would be the slow and simple thing it should rightly be.
That is what the Red Pitaya is doing (edit: will do...).  In fact it is (edit: will be...) capable of a lot more that the DSLogic, but at a higher price point.
http://www.kickstarter.com/projects/652945597/red-pitaya-open-instruments-for-everyone
 

Offline dunkemhigh

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Re: DSLogic
« Reply #35 on: January 12, 2014, 01:59:02 am »
You pays your money and takes your choice :)
 

Online Kean

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Re: DSLogic
« Reply #36 on: January 12, 2014, 02:11:30 am »
Or, if you're like me - you hedge your bets and throw money in both directions!  :-+
 

Offline dunkemhigh

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Re: DSLogic
« Reply #37 on: January 12, 2014, 02:22:23 am »
Another man with an accumulation of shelf-ware ;)
 

Offline BloodyCactus

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Re: DSLogic
« Reply #38 on: March 27, 2014, 02:40:50 am »
looks like the dslogic is shipping with its nifty little aluminium case this week! right in its stated delivery window. nice to have a kickstarter come in on its said schedule!
 

Offline jancumps

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Re: DSLogic
« Reply #39 on: June 08, 2014, 04:50:02 pm »
... anyone bought one?
 

Online Kean

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Re: DSLogic
« Reply #40 on: June 09, 2014, 10:16:21 am »
... anyone bought one?
I got mine - just the starter kit (core board), but in the nice aluminium case.
It seems to work fine, and the software is reasonable (almost but not quite Saleae quality).  I haven't yet done any serious measurements with it to verify timing and bandwidth.
It also shipped in better than average packaging for a Chinese product.
 

Offline BloodyCactus

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Re: DSLogic
« Reply #41 on: June 10, 2014, 02:33:33 am »
yep. nice case it came in, as stated above, it was packaged like a real product not just a padded bag!

i build the software from github source. it would be nice to see it integrated back to sigrok but for now its not. builds and seems to work just fine. under linux you need to run it as root tho (for me at least) so it can access the usb device and upload its firmware each time it runs.
 

Offline motocoder

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Re: DSLogic
« Reply #42 on: June 17, 2014, 05:52:45 pm »
yep. nice case it came in, as stated above, it was packaged like a real product not just a padded bag!

i build the software from github source. it would be nice to see it integrated back to sigrok but for now its not. builds and seems to work just fine. under linux you need to run it as root tho (for me at least) so it can access the usb device and upload its firmware each time it runs.

You can almost certainly fix the root requirement with a udev rule to set the permissions on the USB device.
 

Offline JohnSL

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Re: DSLogic
« Reply #43 on: July 14, 2014, 08:39:01 am »
I just setup my DSLogic box today, but I'm not sure how to get it to work. I've never used a logic analyzer before (I have used oscilloscopes), and I couldn't find a manual anywhere. I installed the software and drivers, and then fired up the DSLogic application. It found my DSLogic box. I also hooked up the ground, and channel 0 and 1 to a circuit that I'm playing around with. What I expect to see is that when channel 0 drops to 0V, channel 1 will drop a short time later. I want to see what this delay is. Right now I'm driving my board with a 1 Hz input signal.

I set DS Logic to use 1k samples @ 10Khz. I'm not sure what this means, as there is no manual. Does it mean that I need 1,000 samples before anything will show up on the screen? Right now I see the big round logo with three circles that alternately light up. I don't see any traces on any of the channels.
 

Offline miguelvp

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Re: DSLogic
« Reply #44 on: July 14, 2014, 08:49:03 am »
I just setup my DSLogic box today, but I'm not sure how to get it to work. I've never used a logic analyzer before (I have used oscilloscopes), and I couldn't find a manual anywhere. I installed the software and drivers, and then fired up the DSLogic application. It found my DSLogic box. I also hooked up the ground, and channel 0 and 1 to a circuit that I'm playing around with. What I expect to see is that when channel 0 drops to 0V, channel 1 will drop a short time later. I want to see what this delay is. Right now I'm driving my board with a 1 Hz input signal.

I set DS Logic to use 1k samples @ 10Khz. I'm not sure what this means, as there is no manual. Does it mean that I need 1,000 samples before anything will show up on the screen? Right now I see the big round logo with three circles that alternately light up. I don't see any traces on any of the channels.

I don't have a DSLogic box or a logic analyzer for that matter, but I can explain what is happening to you.

10KHz sampling rate is 10,000 samples per second and you are capturing 1K or 1,000 so you are just getting one tenth of a second or 0.1 seconds. Since your board is running at 1 Hz (1 cycle per second) then you won't see anything.

So you need to lower the sample frequency to be lower, or increase the number of samples captured to be higher than the sample frequency, or change your board to run quicker than 1 Hz.


I hope that makes sense.
 

Offline JohnSL

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Re: DSLogic
« Reply #45 on: July 14, 2014, 10:43:43 am »

I don't have a DSLogic box or a logic analyzer for that matter, but I can explain what is happening to you.

10KHz sampling rate is 10,000 samples per second and you are capturing 1K or 1,000 so you are just getting one tenth of a second or 0.1 seconds. Since your board is running at 1 Hz (1 cycle per second) then you won't see anything.

So you need to lower the sample frequency to be lower, or increase the number of samples captured to be higher than the sample frequency, or change your board to run quicker than 1 Hz.

I hope that makes sense.

Yes, thanks, that makes sense. I also tried 16 M samples at 10 KHz (that's the slowest sampling rate), and I still don't see anything. It just keeps showing the dancing dots that seem to indicate it's collecting data. When I click the stop button and zoom out, I see the time range as being 1.64 seconds. But I still don't see any traces.

So I'm wondering if perhaps my box isn't working correctly.
 

Offline madworm

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Re: DSLogic
« Reply #46 on: July 14, 2014, 10:48:28 am »
Look at the trigger settings!

You will most likely have to set up a trigger condition. E.g. channel 0 going from LOW to HIGH or something along those lines.
 

Offline JohnSL

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Re: DSLogic
« Reply #47 on: July 14, 2014, 02:47:45 pm »
Look at the trigger settings!

You will most likely have to set up a trigger condition. E.g. channel 0 going from LOW to HIGH or something along those lines.

I tried several different ways to set a trigger, and I still don't see any waveforms showing up. So I've sent an email to their tech support. I was hoping someone would give me the "magic sauce" I was missing so I could get it working this weekend. Oh well.
 

Offline elektrinis

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Re: DSLogic
« Reply #48 on: June 23, 2018, 01:52:00 am »
Fast forward 4 years and...
Anyone use DSlogic now? They also have a DScope and the software looks okay. I wonder if it is safe to buy now.
Could not find any reviews of DScope so far.
Also there seems to be at least 3 versions of DSlogic available:
1. 2.5mm pitch inputs
2. 2mm pitch inputs with 256k memory
3. 2mm pitch inputs with 256M memory
 

Offline Doctorandus_P

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Re: DSLogic
« Reply #49 on: July 01, 2018, 05:48:04 am »
Just had a look on their website.
Almost all products are "out of stock".
Hackaday sold it for a while, but it seems that a lot of products are dissapearing from Hackaday and they might be phasing out the "shop" on their site.  :-//

From what I've heared DSlogic has modified the (old) Sigrok / (Pulseview) source a lot and in ways that are almost impossible to port back.

For a logic Analyser I use the cheap (EUR 5) "24m 8ch" boxes from Ebay / Ali / China with Sigrok & Pulseview. (Any Cypress Cy7C68013A development board will do).
These EUR 5 LA's are plenty for debugging microcontroller stuff such as SPI  UART, RS485 and a lot of other serial protocols. I've even captured low speed USB with that box and Pulseview has decoders for it.
A general development board for the Cypress supports 16 channels, but does not have the extra input protection that the logic analyser boards have.

I will gladly buy a "better" logic analyser, especially if it is oficially supported by Sigrok and it means pushing some money in their direction.
 


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