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RC Equipments => Tools, Materials and Building Techniques => Topic started by: satyagupta on May 13, 2020, 01:26:25 PM



Title: General Questions about Oscilliscope
Post by: satyagupta on May 13, 2020, 01:26:25 PM
Hello All,

I am posting in RCI after a very long time. (nostalgic  8-) )

I want to know few information about oscilloscope. Since they cost a lot of money, i want to make sure that i buy the right one.

I am working on a new product and it needs to check lot of signals/frequencies. Hence planning to buy an oscilloscope.

I have few questions.

Most of my products would have mcu either atmega328p or STM32 Arm

Q's

1. How many channels should i select 2 or 4?
2. 70Mhz or 100 Mhz
3. Does the brand matters? tecktronix/keysight etc
4. What config you suggest for a hobbyist who has a budget of around 50K


Thanks in advance  :hatsoff: :hatsoff: :hatsoff:

I understand RCI does not have lot of people online as we used to have back those days. But i hope i get few replies  :thumbsup: :thumbsup:


Title: Re: General Questions about Oscilliscope
Post by: ujjwaana on May 13, 2020, 03:09:30 PM

1. How many channels should i select 2 or 4?
More the Better
2. 70Mhz or 100 Mhz
70Mhz would be fine unless you are looking at very fast signaling protocol. Remember you dont need a Scope fast as the Clock frequency of the MCU, unless you plan to debug the Board/MCU itself.
3. Does the brand matters? tecktronix/keysight etc
You wont get a decent featured scope from these companies for under 50K.
4. What config you suggest for a hobbyist who has a budget of around 50K
You can find shops sellign refurbed, old Scope of these companies, sourced from College/Labs discarding them. I have a HP 54601B, 4 Channel, 100Mz Digital Scope from 90's, which I bought for 11K. But I mostly use it for RF work. For Digital Electronics, you better buy a DSO, with lots of Feature (more channel, math functions etc). For 50K, you can get the latest 4Ch -100Mhz Scope from companies like Rigol, Hantek, Even Unit-T.

But before you really buy a Scope, try with PC based Logic Analyser, because unless you are developing a new Hardware, you can live with PC based Logic Analysers for 90% of debugging involving protcols etc...

https://www.tanotis.com/products/sparkfun-usb-logic-analyzer-25mhz-8-channel?gclid=CjwKCAjwte71BRBCEiwAU_V9h5LB558BzDa8JYFx36JR3NYis06ti3e-KWlo249PlX2JQGo8q56oiRoC_2QQAvD_BwE


https://robu.in/product/usb-logic-analyze-24m-8ch-mcu-arm-fpga-dsp-debug-tool/?gclid=CjwKCAjwte71BRBCEiwAU_V9hz7fItSCHHEgALtdwBcXnG72t3FkSESW4nszWPMets265GMjDwMF7xoCLU8QAvD_BwE


Title: Re: General Questions about Oscilliscope
Post by: satyagupta on May 13, 2020, 06:07:27 PM
What exactly you meant when you say
unless you are developing a new Hardware


Title: Re: General Questions about Oscilliscope
Post by: ujjwaana on May 13, 2020, 08:58:40 PM
What exactly you meant when you say
unless you are developing a new Hardware

I mean if you are developing a  new sensor and writing Protocol for it ... else if you are developing a board using general purpose Sensors which have standard and published API/Library and communicate using standard protocol like I2C, SPI, CAN, etc , you can use the cheap Logic Analyazer instead of DSO , because the Logic Analyser can easily show you the communication signal form and even the decode the underlying protocol  and help you debug.  Like if you are using Parallel/SPI LCDs, Sensors communicating in SPI/I2C , you can use logic analyzers like BusPirate etc to sniff the traffic and see what is actually reaching to devices and what they are replying with, if at all.

Only if you are developing something where the MCU or peripheral devices involves Raw data format (Analog or even Digital), only then you will need Scope. 

I would again highly suggest first  buying one of these cheap Logic Analysers and give a try (of course giving time learning how to use them). Only if end of the day you find they are not enough, look for a used / new DSO ( Digital Storage Oscilloscope).


Title: Re: General Questions about Oscilliscope
Post by: satyagupta on May 13, 2020, 09:02:21 PM
Hmmm you have a point, but these LA would help with frequency test/analysis??

For example, I want to check if data is been transmitted from a module wirelessly but not received properly


Title: Re: General Questions about Oscilliscope
Post by: ujjwaana on May 13, 2020, 09:28:19 PM
Say its a UART data you want to send wireless. So in theory, The Data on Tx pin of Transmitter should re-appear on the Rx Pin of (Paired) Receiver. That you can do by putting LA on both pins and comparing their trace on Screen or first Save and  then compare.

I doubt you would even intend to "Sniff" the Radio Spectrum, reconstruct the Data transmission from RF and then debug. For those thing, you might need more than DSO. Actually even if you want to do something like that (sniffing the Radio traffic) , you can get yourself a Cheap $10-20 RTL-SDR, or more standard $60-$150 "Hack RF".

Again I repeat, a DSO would absolutely help in debugging and is de-facto tool, but dont expect magic out of it. There are cheaper , though more convenient tools like a USB Logic Analyzer, which can more suite your day to day debugging issues.
For example, a classic problem with Chinese SPI LCDs is that they have a totally different hard coded Address than what you will see in Example Code using original Ardafruite/Sparkfun module.  You can easily do a Scan and catch the actual address to which the Module responds, using the LA.


Title: Re: General Questions about Oscilliscope
Post by: satyagupta on May 14, 2020, 10:19:12 AM
 :thumbsup: :thumbsup: :thumbsup: :hatsoff: :hatsoff: :hatsoff:

Thanks Ujjwaana, you had mentioned Hantek for cheaper option. How is that for a oscilloscope?

I am getting DSO4104B model for around 40k locally


Title: Re: General Questions about Oscilliscope
Post by: ujjwaana on May 14, 2020, 12:34:57 PM
If you are finally spending so much, go for RIGOL instead of Hantek as Regol has more presence and reputation at least among small-medium enterprise / individual service center than Hantek. You can try to bargain these listed prices and even 100Mhz one (with Wave generator) would  come under 50K :

https://www.salicontech.com/digital-storage-oscilloscope.html

DS1104Z - 4 Channel DSO with 100 MHZ Bandwidth,1GSa/s
DS1074Z-S  70MHz ,4Ch.,1GSa/s,12Mpts Digital Storage oscilloscope with 25Mhz,2ch.



Title: Re: General Questions about Oscilliscope
Post by: satyagupta on May 14, 2020, 12:37:48 PM
Thank you I will follow up with them :)


Title: Re: General Questions about Oscilliscope
Post by: asperised on July 15, 2020, 06:03:24 PM
This maybe an old post but I didn't want to start a new one. I am also considering getting an oscilloscope and have been leaning towards the Rigol 1054Z. It should be more than enough for my needs as of now and it's hackable to 100MHZ which should make it future proof. Is it a good choice? Are there other options out there in India? Siglent and the likes? I also recently got an offer through an indiamart reseller for a keysight EDUX1052A for 33,000₹ + taxes. Seems like an amazing deal considering it's keysight but just two channels might be an issue and it doesn't look like there are any hacks for the EDU version to upgrade the bandwidth which might be a bottleneck later. Is the Rigol worth it? It's available for around 37k on salicontech, couldn't find it any cheaper anywhere.

Nitesh