Considering purchasing a Logic Analyzer

[Agent24]

Re: Considering purchasing a Logic Analyzer

Are you using the latest version of Sigrok from their github repository? How stable is it? I've been planning on using the libserialport library that Sigrok uses and develops (I believe) to control my Weller WHP3000 preheater. I wanted to release the code open-source on github for other people but I didn't want to have to write separate code for Windows and for Linux. libserialport seems extremely portable and does all the hard work for me.

At the time, I used the latest one downloaded from the latest ubuntu repos (which was for a higher version than 12.04 I am running on the machine I use for electronics stuff). At that time it was the same version as the one on their official download page IIRC. I don't know if it would be latest version now. I haven't needed to use it for a while.

Mostly it worked fine, but sometimes it would stop capturing prematurely. This happened in pulseview and sigrok. I suspect the hardware. I think I found a post about it online saying the same thing. I can try to find it again if you want to know the exact problem.

But aside from that issue, everything seemed OK for what I did. I never used protocol decoding so far because I so far have not needed to. But from the demo capture files included it does seem to work.

Good thing about it being open source, I expect it would be quite easy to implement new decoders.

[Spork Schivago]

Re: Considering purchasing a Logic Analyzer

I think I'm going to be happy with my 16702B when it comes. I was thinking of replacing the 18GB SCSI2 drive with one of those SCSI2SD adapters. They plug into a 50-pin SCSI port and can emulate SCSI 1 or 2 from what I've read and you just use a MicroSD card. They support SDSC, SDHC, and SDXC. The price is a little steep compared to something like a 146GB SCSI Ultra 320 drive but I'd still need an adapter for that to work in this. If the hard drive is bad, I'll probably by the SCSI2SD adapter. If it's good, I'll probably wait a few months before making the upgrade.

[Spork Schivago]

Re: Considering purchasing a Logic Analyzer

Sounds good, if you can get it going.

For the record, I bought a $20 USB one (LCSoft Devboard\knockoff) and built my own input protection board. I use the Sigrok\Pulseview software in Linux. It doesn't always work perfectly, but it has been quite useful so far. I would like to get something better one day but for the price they are surprisingly good value.

Are you using the latest version of Sigrok from their github repository? How stable is it? I've been planning on using the libserialport library that Sigrok uses and develops (I believe) to control my Weller WHP3000 preheater. I wanted to release the code open-source on github for other people but I didn't want to have to write separate code for Windows and for Linux. libserialport seems extremely portable and does all the hard work for me.

[stj]

Re: Considering purchasing a Logic Analyzer

For the record, I bought a $20 USB one (LCSoft Devboard\knockoff) and built my own input protection board.

that's the same basic hardware as the one i linked for under $10
i got one expecting to have to change the buffer chip only to find the chinese had already updated the board!

[Agent24]

Re: Considering purchasing a Logic Analyzer

Sounds good, if you can get it going.

For the record, I bought a $20 USB one (LCSoft Devboard\knockoff) and built my own input protection board. I use the Sigrok\Pulseview software in Linux. It doesn't always work perfectly, but it has been quite useful so far. I would like to get something better one day but for the price they are surprisingly good value.

[Spork Schivago]

Re: Considering purchasing a Logic Analyzer

OMG! I'm so excited! I got the 500MHz bandwidth 2 Gigasamples / second two channel digitizing storage oscilloscope module! Ebay wanted anywhere from 500$ to 1000$ for them but this guy was selling one as is because he couldn't get the triggering to work on it. He said all he did to test was hook it up to his signal generator. I've already downloaded the service manual for it but I'm hoping it's going to be some as simple as it just needs calibrating! I see in the user manual, there's a calibration routine for the triggering stuff. He wanted 150$ + 20$ shipping, I offered 75$, he counter offered 115$, I took it and went for the faster but cheaper shipping (USPS was cheaper and faster than UPS ground) and I paid a total of around 127$ for it!!!!

[Spork Schivago]

Re: Considering purchasing a Logic Analyzer

I just need to figure out if this accessory kit will work with my Logic Analyzer now or not. If not, I need to find one that will work.

http://www.ebay.com/itm/111863055111...%3AMEBIDX%3AIT

[Spork Schivago]

Re: Considering purchasing a Logic Analyzer

Oh, it's not that bad I guess. 22 inches deep by 16.75 inches wide by 9 inches high.

[Spork Schivago]

Re: Considering purchasing a Logic Analyzer

wow - nice spec but it's FUCKING HUGE!!!

Wait, how big is huge? I was thinking around the size of my oscilloscope! I see I can add a 500MHz Bandwidth two-channel storage oscilloscope module but they're freaking expensive! They can be daisy chained together though, so if I could have 2 of them for 4 channels, 3 for 6 channels, 4 for 8 channels, etc. Maybe in the future!

[stj]

Re: Considering purchasing a Logic Analyzer

wow - nice spec but it's FUCKING HUGE!!!

[stj]

Re: Considering purchasing a Logic Analyzer

if you replace fans, get the flow-spec of the originals and dont go under with the new ones.

[Spork Schivago]

Re: Considering purchasing a Logic Analyzer

I bought one! I got the HP 16702B model with 100Mb ethernet! It has a built-in SCSI CD-ROM drive so I can reinstall the OS and everything. It only has an 18GB hard drive but I plan on upgrading that to a 146GB SCA Ultra320 SCSI drive. I also want to replace the fans inside of it to quiet it down a little bit. I plan on connecting to it mainly via ethernet with an X-Windows remote session. It comes with Option 003 as well!!! And it comes with two modules, the 16771A 48-Channel Pattern Generator Module and the 16740A 48-Channel Pattern Generator Module!!!

It needs some TLC. It needs 3 filler plates and although it comes with PODS, it doesn't come with clips or grabbers. I'll have to pick some of those up somewheres. I'm so excited!!! This is the one I bought:

http://www.ebay.com/itm/172031834984...%3AMEBIDX%3AIT

[stj]

Re: Considering purchasing a Logic Analyzer

i2c is old, i'd expect them to handle it, not sure about spi - specially as it can be pretty fast.

do your homework & download some equipment flyers/manuals

and remember you need a serial/ethernet port on the analyser and the sotfware for the pc side to transfer your captures.

[Spork Schivago]

Re: Considering purchasing a Logic Analyzer

i would avoid the old desktop stuff,
unless your going to link it to a pc they wont decode modern protocols - simply because the units are older than the modern protocols like can,lin etc.

they are great for what they were designed for though, watching data buses on boards.

Thank you. So would I be able to use it for I2C and SPI type stuff? The older benchtop models I mean?

[stj]

Re: Considering purchasing a Logic Analyzer

i would avoid the old desktop stuff,
unless your going to link it to a pc they wont decode modern protocols - simply because the units are older than the modern protocols like can,lin etc.

they are great for what they were designed for though, watching data buses on boards.

[Spork Schivago]

Re: Considering purchasing a Logic Analyzer

Thanks Stj! I'm trying to decide now between three of them. The USB one you showed me, an HP 16500B with a 16550A Module or waiting to find something like this HP 16702A that came with three 16555A modules and one 16522A module.
http://www.ebay.com/itm/161896554869

If I saw this HP 16702A before it sold, I would of probably of bought that one!

[stj]

Re: Considering purchasing a Logic Analyzer

Oooh! RS232 would be nice too. To be able to see RS232 traffic and save it. That'd be real nice. I'm sure I'd use that in the future. I got devices that can talk via RS232. I'd like to be able to decode that traffic so I can figure out the protocol and write my own software to communicate with the devices via the PC.

for that, get a pair of usb-serial adapters and do a "man-in-the-middle" style attack.
there is software for that.

[stj]

Re: Considering purchasing a Logic Analyzer

look at these softwarez
https://www.saleae.com/
http://sigrok.org/

both do protocol decoding with that ebay hardware.

limitations of the saleae clone, no trigger input, only 8 lines, only 24mhz limit.
however, it's a lot cheaper than a 16/32line 100mhz unit,
and it's good enough for sniffing most comms.
works on 2v-5v signals btw.

[Spork Schivago]

Re: Considering purchasing a Logic Analyzer

Oooh! RS232 would be nice too. To be able to see RS232 traffic and save it. That'd be real nice. I'm sure I'd use that in the future. I got devices that can talk via RS232. I'd like to be able to decode that traffic so I can figure out the protocol and write my own software to communicate with the devices via the PC.

[Spork Schivago]

Re: Considering purchasing a Logic Analyzer

I've definitely been looking at some of the USB ones, because of their prices. Basically, is there any time where I wouldn't be able to do something with the USB ones but would be able to do it with a benchtop model?