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 Post subject: Looking for Oscilloscope/Logic Analyzer recommendations.
PostPosted: May 28th, 2019, 18:33 
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Joined: May 26th, 2017, 12:52
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I'm looking to get an oscilloscope/logic analyzer for monolith pinout detection and phone repair, but I'm unsure of what are some good affordable brands of oscilloscope.


What kind of specs should I be looking for in an oscilloscope/logic analyzer?


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 Post subject: Re: Looking for Oscilloscope/Logic Analyzer recommendations.
PostPosted: May 28th, 2019, 18:49 
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Rigol appears to be a good, but relatively inexpensive, brand.

The EEVblog forum would be a good place to ask.

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 Post subject: Re: Looking for Oscilloscope/Logic Analyzer recommendations.
PostPosted: May 29th, 2019, 15:48 
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fzabkar wrote:
Rigol appears to be a good, but relatively inexpensive, brand.

The EEVblog forum would be a good place to ask.


Thank you for your recommendations!

I'll check out the EEVBlog Forums for more ideas and recommendations.


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 Post subject: Re: Looking for Oscilloscope/Logic Analyzer recommendations.
PostPosted: May 29th, 2019, 22:39 
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There are many Rigol models, I would say fine for a scope, but if you are going to spend the amount a decent rigol LA would be, I would spend it on something else. combo ones will not give you a great LA.


a ZeroPlus LAP-C(322000) should do for NAND pinout.

I have a Logic Pro 16 https://www.saleae.com/ and new firmware has increased capability where it might do the job as well, though 16 channels not really enough.


I still haven't seen anybody recommend a LA that works great for pinout discovery, and is affordable, say around $1,000 -$2,000


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 Post subject: Re: Looking for Oscilloscope/Logic Analyzer recommendations.
PostPosted: May 30th, 2019, 1:21 
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Joined: October 24th, 2009, 15:22
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HaQue, we use LA - it cost 99$ :)

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 Post subject: Re: Looking for Oscilloscope/Logic Analyzer recommendations.
PostPosted: May 30th, 2019, 1:52 
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arvika wrote:
HaQue, we use LA - it cost 99$ :)


Hey there!

Yes, I know you can get away with ones cheaper if you are skilled :-) Though I haven't seen one that cheap that I would consider having the specs needed. Good to know.

But I still stand by my last point, even if I change it slightly:

Quote:
I still haven't seen anybody recommend a LA that works great for pinout discovery, and is affordable, say around $99 - $2,000



no-one is saying model numbers or resources for the people wanting to get into pinout discovery.

I realise there is excellent training available from Rusolut for VNR, I mean in the community as many cant afford travel, time or the course fee.

I understand the unwanted competition argument.


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 Post subject: Re: Looking for Oscilloscope/Logic Analyzer recommendations.
PostPosted: May 30th, 2019, 14:24 
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We are using from beginning ZeroPlus LAP-C (322000) and sometimes even this it's to slow to catch some frequency. In some rare cases (which we usually get :roll: ) cheap LA will not "catch' signal properly... also most of cheap one don't have NAND decoder which can help too....

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 Post subject: Re: Looking for Oscilloscope/Logic Analyzer recommendations.
PostPosted: July 16th, 2019, 4:50 
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Find the crystal frequency on the embedded system under test; buy an oscilloscope with sampling frequency 2x minimum of crystal frequency and 10x of crystal frequency under test for best results.
Its very easy to think this way. 1)Nyquest limit considerations and basic math used to calc max allowed input frequency
2)All the data lines/clock lines etc will be definitely lower than the crystal frequency. :D
So you are safe with fulfilling just point number 1.


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 Post subject: Re: Looking for Oscilloscope/Logic Analyzer recommendations.
PostPosted: July 16th, 2019, 13:10 
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sin wrote:
Find the crystal frequency on the embedded system under test; buy an oscilloscope with sampling frequency 2x minimum of crystal frequency and 10x of crystal frequency under test for best results.
Its very easy to think this way. 1)Nyquest limit considerations and basic math used to calc max allowed input frequency
2)All the data lines/clock lines etc will be definitely lower than the crystal frequency. :D
So you are safe with fulfilling just point number 1.


Well,
Simran Arora Son Of Anaes Arora ,Would You Please Stop Bombarding The Forums With Useless Comments Boss .Really You Have No Idea Of NAND ,Its Working Etc Etc Seriously .All The Stuff You Wrote Make ZEROOOOOOOOOO Sense

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 Post subject: Re: Looking for Oscilloscope/Logic Analyzer recommendations.
PostPosted: July 16th, 2019, 15:23 
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Joined: September 17th, 2016, 16:06
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Hi Little Red Ridinghood , surely I am a proud son of an Anesthesiologist Doctor who is a Gold Medalist of Mumbai University. I am son of that healer and pain reliever who has passed from the best medical school in Mumbai. I am the son of a person who put up a fabulous company called Data Recovery Factory which runs about 419 Reviews on Google reviewed by clients who really loved his services. I am the son of a man who helped me with a soldering iron when I was just 12!
So yeah :) Anaesarora/Dr.Arora is far beyond as a professional and a person. He is some one who can fix humans and hard drives too :) Relieve the pain of the person under operation and reliving the pain of a client suffering from data loss and having both of the kinds recover gracefully.

Now as far as my general qualifications stand, I am a Diploma in Audio Engineering associated with Bollywood Music Industry (you cant even dream of being in this zone of professionals, and doctors too! ). I am a bachelors degree holder in electronics and communication who has studied 4 semester of hardcore math,electronics(digital/analog design), Apart from that more 4 semesters of Analog Communication, Digital Communication, RF theory,Signals and Systems, Audio DSP, VIDEO DSP, a core understanding of networking and what not. You have not practically even passed 12th grade. You are fit as a peon in any Indian Government office and nothing beyond. But some how you got into salesmanship early in your career and turned into DR to dupe your customers...what else ?


Better luck at that. :)

And to understand what I said. Which is quite generic for any EE or ECE grad, you will not understand it because you have a small mind. Can't help with that.

I also feel, honestly, by reading all your previous posts here. I feel you are deeply hurt in life. I don't have sympathies for that and neither a solution. So feel free to be in your comfort zone, shit posting around, eating mud and getting abused for life. That's your job and daily appetite.

I don't know if your son will ever be proud of you. I have sympathies for him.

--


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 Post subject: Re: Looking for Oscilloscope/Logic Analyzer recommendations.
PostPosted: July 16th, 2019, 19:37 
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I don't know what is up with you two, and don't care, but Sin's answer is ok, but not extremely helpful to regular Joe without decent electronics background that want to start finding pinouts.

The hardest part is parsing all the technical specs to make sure any LA you might be interested in will actually do the job. On the surface you might see a 200MHz, 500MHz one etc, but read on and discover that as soon as you add more sampling channels, it reduces down sample rate to below what is required.

If you know what you are looking for, and have experience, you might be able to get away with lower spec one.. but given the fact that one is asking for recommendations, it is a safe bet that they don't have the required experience. Plus if the did, they wouldn't need to ask.

Amarbir: which LA do you use?


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 Post subject: Re: Looking for Oscilloscope/Logic Analyzer recommendations.
PostPosted: July 17th, 2019, 2:20 
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Joined: September 17th, 2016, 16:06
Posts: 431
Location: India
Ok let me brush up basic concepts

Nyquest theorem or nyquist theorem suggests that to capture an analog AC signal and represent it correctly without any aliasing of the input frequency one needs to have the sampling frequency ATLEAST 2x the intended input frequency. This is the first theorem one learns when one starts to understand basics of SAMPLING.

Now if you have a device which runs on a clock of 10MHz. As per the theorem one has to have an oscilloscope of 20MHz sampling frequency for faithful representation of the AC input signal. However in reality this minimum is never enough and one needs to have a measurement unit atleast 4 to 10x of the intended input AC frequency. So atleast 40MHz is a good start to sample a 10MHz clock signal.

Not following this law causes ALIASING which means that the fundamental frequency will take a different form at multiples of the input frequency and appear across the whole band on a FFT. However the intended input frequency will not be measured correctly or will not be measured at all.

So if a hard drive crystal oscillator or a SSD crystal oscillator is at X MHz rating, one needs to buy a DSO of atleast 4X sampling frequency for faithful representation.

Also if you say that the whole SSD/embedded system works at 25MHz, that would mean all clock and data lines will be mostly lower than 25MHz which are to be measured and buying a DSO of 100MHz ensures that all the signals in sub system will get measured correctly.
However there is a chance that the microcontroller/embedded system under test does an internal clock multiplication of the main clock line. Which means generating say, 50MHz from 25MHz line. In that case to measure 50MHz line you will require a DSO that does 200MHz input sampling.

These all numbers are just for reference to understand how to decide input sampling frequency(which decides faithful representation of measured signal) while buying the DSO.

Most DSOs are 10 - 12 bit plus systems so you will not have to worry about the resolution part.

This is from the basics of EIM (electronics instruments and measurements) that we learn here in our 4th semester.
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 Post subject: Re: Looking for Oscilloscope/Logic Analyzer recommendations.
PostPosted: July 17th, 2019, 11:39 
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fine, but OP is talking about monolith pinout discovery, and signals are a lot faster.
And as I said before, specs of the LA should be carefully scrutinised to make sure that once you start using 20 plus channels, the effective specifications you have available are not much, much lower.


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 Post subject: Re: Looking for Oscilloscope/Logic Analyzer recommendations.
PostPosted: July 17th, 2019, 13:26 
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Joined: September 17th, 2016, 16:06
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HaQue wrote:

The hardest part is parsing all the technical specs to make sure any LA you might be interested in will actually do the job. On the surface you might see a 200MHz, 500MHz one etc, but read on and discover that as soon as you add more sampling channels, it reduces down sample rate to below what is required.




Adding more sampling channels causes this because a single ADC is used with a MUX. It takes more processing time aswell and conversion time for every reading has to be made of a feasible size to record stuff correctly across multiple channels.
In such cases one should opt for devices that have multiple individual ADCs.

Say I want to measure 20 channels. I have 2 multiplexed ADCs with 10 channels.... every ADC doing 10 channels. Now it takes more time to process, the sampling frequency is decreased, aliasing occours. On the contrary if I have 5 ADCs and 10 channel per ADC, I can use 2 channel across 5 ADCs and still attain higher sampling frequency to capture high frequency signals faithfully.
Hence it is important to know how many ADCs your LA should have.


What I am providing is a very generic information on instrumentation and not recommending any brand. Knowing what is to be measured is always a pre requisite. In that case one can take a middle route. Buying things of more than required and utilized capabilities is a waste of money. So why not add up on some information before hand and spend wisely, choose well and live happily.

:D
--


Last edited by sin on July 17th, 2019, 13:40, edited 1 time in total.

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 Post subject: Re: Looking for Oscilloscope/Logic Analyzer recommendations.
PostPosted: July 17th, 2019, 13:29 
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HaQue wrote:
fine, but OP is talking about monolith pinout discovery, and signals are a lot faster.
And as I said before, specs of the LA should be carefully scrutinised to make sure that once you start using 20 plus channels, the effective specifications you have available are not much, much lower.


I know. I am just giving examples.. I am not saying a SSD runs on a 25MHz...I have clearly stated EMBEDDED system which means the approach can be applied to SSDs too as they are equally embedded.

Also, my recommendation was about oscilloscope and specifically DSO and not logic analyzer.... an oscilloscope is not a logic analyzer and the OP mentions both.
If he means 'OR' then more basics need to be cleared in terms of general electronics.

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 Post subject: Re: Looking for Oscilloscope/Logic Analyzer recommendations.
PostPosted: July 17th, 2019, 20:53 
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problem is, we see this "generic" advice given to people new to this type of research and it helps them in no meaningful way. Sure they could study for a year...


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 Post subject: Re: Looking for Oscilloscope/Logic Analyzer recommendations.
PostPosted: July 18th, 2019, 18:44 
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Joined: September 17th, 2016, 16:06
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One click fix. One suggest buy...Both are dangerous.
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 Post subject: Re: Looking for Oscilloscope/Logic Analyzer recommendations.
PostPosted: July 18th, 2019, 23:42 
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Location: Adelaide, Australia
sin wrote:
One click fix. One suggest buy...Both are dangerous.
--


Yes I agree, but a short list of alternatives with pros and cons can go a long way to help someone understand what features/specs are important.

To be honest, if one were to buy a LA that was recomended, and they started using it only to discover that they were missing something, or performance was not adequate... Then I would call this a reasonable outcome as they learnt something and now have experience and a better understanding what to look for.

Currently they still have relatively little to go on.

It would not be the end of the world to have to sell it and buy another one. I bought a Hantek similar to this: https://www.banggood.com/Hantek-4032L-Logic-Analyzer-32Channels-USB-Oscilloscope-Handheld-2G-Memory-Depth-Osciloscopio-Portat-p-1376105.html?gmcCountry=AU&currency=AUD&createTmp=1&utm_source=googleshopping&utm_medium=cpc_bgs&utm_content=frank&utm_campaign=pla-tools-1-au-pc-0625&ad_id=357626386482&gclid=EAIaIQobChMI7Im-54fA4wIVyoRwCh3ofQ9WEAQYAiABEgKIBfD_BwE&cur_warehouse=CN
and sold it again for minimal loss, it was a piece of junk for anything not basic serial embedded stuff.

Quote:
I have clearly stated EMBEDDED system which means the approach can be applied to SSDs too as they are equally embedded

BTW the LA was asked for to do MONOLITH pinout discovery. Nothing to do with SSDs, though currently there is a BGA SSD on the market, so I am talking regular Monolith UFD, SD, MicroSD etc


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 Post subject: Re: Looking for Oscilloscope/Logic Analyzer recommendations.
PostPosted: July 19th, 2019, 11:25 
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Joined: September 17th, 2016, 16:06
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Location: India
Hi, with respect to that, living in Mumbai we have a few good stores that deal with such products that are in GHz range that way. Maintaining decent relations with the store managers and bosses helps me get a few things delivered on trial basis (demo units). If the thing fits my needs, i usually pick up the demo piece itself. If the product is not suitable for my application they either help with another model / company or just take the demo unit back. In such cases it is always helpful to bear with local transportation charges and one free meal to the delivery and pick up boy usually works out good.
So if such a try before you buy option exists, one can opt for that as well.

--


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 Post subject: Re: Looking for Oscilloscope/Logic Analyzer recommendations.
PostPosted: July 19th, 2019, 11:28 
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Joined: September 17th, 2016, 16:06
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Location: India
SSD, monoliths, or audio preamplifiers..if there is a clocking fundamentals and AC signal digitization principles will always be same.
And the way to capture them will also be on the said theory
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