Should I Buy the Finrsi DSO510 on a Tight Budget? - Page 1
Forum section: electronics / testgear

author: osmax_br
author_rank: Regular Contributor
timestamp: January 26, 2025, 12:07:53 pm
content: I am am a hobbyist who works on ESP32 projects, TFT displays, I2C devices, and does some circuit debugging here and there. I'm looking to buy an oscilloscope on a budget, specifically thinking about the Finrsi DSO510 (10 MHz, 48 MS/s, + 50 kHz function generator). My budget is very tight, around $30.Of course, my question is NOT whether it is as good as a $300-$400 oscilloscope. My question is: Is it usable or somewhat useful for my work scenarios, or is it just a complete $30 waste of money, essentially e-garbage? Should I avoid buying it altogether and be without an oscilloscope?I don't currently have any oscilloscope and can't afford a proper one for the next 4 years until I'm out of debt. Should I get the DSO510, or would I be better off waiting 4 years to save up for a $300 one?

author: tunk
author_rank: Super Contributor
timestamp: January 26, 2025, 12:22:40 pm
content: For a bit more you can get the Zeeweii DSO1C81 (80MHz, 250MSps).

author: Psi
author_rank: Super Contributor
timestamp: January 26, 2025, 12:30:36 pm
content: Are the BNC grounds connected to mains/USB earth on the Zeeweii DSO1C81 ?

author: artag
author_rank: Super Contributor
timestamp: January 26, 2025, 12:46:54 pm
content: It's essentially a learning tool or toy due to low speed and single channel. It isn't enough to debug your intended targets - it can tell you there's a signal but not what the data is, for example.It may be useful enough to give you a feel for using an oscilloscope, show gross errors such as shorted wiring etc. Kind of like a DMM oir logic probe with just a little more information but frustrating lack of ability. It will tell you something about what you want in a real scope.If it's all you can afford it may better than nothing but I would still aim to replace it with a 2-channel 50MHz (better still 100MHz) unit as soon as you have the money. If buying this makes that significantly harder then that may be a mistake.I would suggest you save up for something better but fill the gap in your knowledge other ways. Maybe join a hackspace and use their equipment (though this too has a cost). Maybe look out for someone givinmg away an old analogue oscilloscope. Most will be better than this one - digital oscilloscopes have to be pretty good to be better than a 50 year old tektronix.Specifically for the I2C/SPI etc jobs, get a $10 USB logic analyser. It will have enough channels to do something useful for digital debug and does something that an old analog can't do - storage. I'm assuming you have a PC to run it - a phone isn't enough.

author: Fungus
author_rank: Super Contributor
timestamp: January 26, 2025, 02:13:24 pm
content: Any'scope is better than no 'scope at all so get whatever you can.Quote from: tunk on January 26, 2025, 12:22:40 pmI think Zeeweii make better 'scopes than FNIRSI. Get FNIRSI for power supplies, Zeeweii for 'scopes.The higher bandwidth and sample rate of the DSO1C81 will make a huge difference on the digital signals produced by an ESP32.

author: osmax_br
author_rank: Regular Contributor
timestamp: January 26, 2025, 03:04:09 pm
content: Quote from: tunk on January 26, 2025, 12:22:40 pmOMG thanks , it is only 10$ more , but I honestly think it is like "too good to be true"Did try one or know someone who tried it?

author: Peabody
author_rank: Super Contributor
timestamp: January 26, 2025, 03:30:42 pm
content: The least expensive two-channel scope I've seen is the SC02. The manufacturer is a mystery, but you can get it at Aliexpress for about $40 including two probes:https://www.aliexpress.us/item/3256807551530702.htmlEdit: Here's another seller at a lower price - about $35 with two probes:https://www.aliexpress.us/item/3256806585989509.htmlI know nothing about it, and have never seen any comments here from anyone who uses it. But the price is certainly right if it's any good. Here's a video review:

author: tunk
author_rank: Super Contributor
timestamp: January 26, 2025, 03:31:53 pm
content: Quote from: osmax_br on January 26, 2025, 03:04:09 pmThere's one user report here:https://www.eevblog.com/forum/testgear/zeeweii-dso1c81/msg5741961/#msg5741961

author: tggzzz
author_rank: Super Contributor
timestamp: January 26, 2025, 03:32:22 pm
content: Quote from: osmax_br on January 26, 2025, 12:07:53 pmYes, repeat noScopes show analogue waveform shape and timing.Strategy for digital circuits: use an analogue domain tool (i.e. a scope) to ensure analogue signal integrity (voltages, timing), then flip to the digital domain and debug digital signals with digital domain tools (i.e. logic/protocol analyser or printf()). Signal integrity can be assured by ensuring repetitive waveforms. That implies that a storage scope is not necessary.Realise that the clock frequency of a digital circuit is irrelevant; theonlyimportant parameter is the rise/fall time. Then you need BW >0.35/trisetime. A scope's samples/second spec is less important.Anyworkingscope which can deal with the edge rates and voltages is better than no scope. Having said that, with sufficient understanding and imagination, a heck of a lot can be done with some switches, LEDs, voltage sources, and a DVM. That was all I had when I designed my first computer, a 6800 with 128bytesof RAM. (No, you couldn't fit an SMS message in that!)If money is tight then realiseLogic/protocol analysers can be very cheap and sufficient for many purposes.Second-hand analogue scopes can be very cheap and sufficient for many purposes - provided they are working. Beginners shouldn't want to have to fix their scopeAlternatively try to find a local hackspace/makerspace, and use their tools.

author: nctnico
author_rank: Super Contributor
timestamp: January 26, 2025, 03:39:03 pm
content: I recommend against getting an analog scope. It will be way less usefull compared to anything digitial for the single shot feature alone.To the OP: don't look at specs alone but try to find reviews from people and pay attention to their remarks where it comes to the user interface. Better specifications mean very little if the user interface makes a device hard to use.

author: osmax_br
author_rank: Regular Contributor
timestamp: January 26, 2025, 04:10:48 pm
content: Quote from: Peabody on January 26, 2025, 03:30:42 pmIn the product description it saysQuoteI didnt understand how it has 2 bandwidths actuallyBut thx for the suggestion, still 2ch is better than one

author: tggzzz
author_rank: Super Contributor
timestamp: January 26, 2025, 04:21:05 pm
content: Quote from: nctnico on January 26, 2025, 03:39:03 pmThe OP is cash-strapped.10/20MHz analogue scopes are almost free nowadays. Certainly my local hackspace seems to be given them on a regular basis. Look at fleabay or gumtree, find a local one, verify it works.Single shot digital signals can be captured perfectly well with a very cheap logic analyser. In many cases that will bebetterthan a low-end scope, digitising or otherwise.The number of times I've had to debug single-shot analogue signals isverylimited. If the OP's use-cases include those, then a digitising scope is necessary; if not, a DSO is optional.If I had to choose betweena moderate working analogue scope plus a basic logic analysera low-end new digitising scope plus nothing elsethen I would choose the first option.That would leave money available for theotherthings the OP has yet to discover they need.

author: tggzzz
author_rank: Super Contributor
timestamp: January 26, 2025, 04:35:05 pm
content: Quote from: osmax_br on January 26, 2025, 04:10:48 pmDigitising scopes are complex, and their internal operation is not intuitively easy for a beginner to understand; beginners often mislead themselves. That's reflected in the specifications; there are many ways in which manufacturers can and do highlight irrelevant numbers simply because they are impressively large.Analogue scopes are much simpler, and the specifications are correspondingly simple. All the controls are visible on the front panel, whereas digitising scopes usually have some important controls buried within a menu structure.I haven't checked, but it might be that the scope bandwidths you mention are higher for repetitive waveforms and lower for single shot waveforms. That's a classic trick manufacturers play. long ago I used a high-end HP scope with a 1GHz bandwidth but only 25MS/s, i.e. 1GHz for repetitive waveforms but ~50MHz for single shot waveforms.

author: ledtester
author_rank: Super Contributor
timestamp: January 26, 2025, 05:52:31 pm
content: Quote from: osmax_br on January 26, 2025, 12:07:53 pmSince you deal a lot with digital signals save $10 for one of these logic analyzers:Low cost logic analyzer -- Mr.T's Design Graveyardhttps://youtu.be/3IA_6MwInVg

author: deadly_penguin
author_rank: Contributor
timestamp: January 26, 2025, 09:50:36 pm
content: $30 is pushing it - I'd usually say not to bother with a super cheap new scope as not being worth the hassle, but with that budget... £30 on fleabay here only usually runs to a knackerd museum piece (at best), though there are a couple of Hantek USB scopes right now that might be okay.As others have said a cheap logic probe paired with a cheap meter (an Aneng an8002/8?) might be better.

author: OLderDan
author_rank: Regular Contributor
timestamp: January 26, 2025, 10:03:31 pm
content: another great logic analyser option (mine still lives on a breadboard!) is using an old android phone/tab with a raspberry pico (if you use the W version you can connect with wifi or usb) and the free scoppy app. I use it often to confirm spi or i2c or uart on my arduino/esp32/pi projects beffore i switch to my pc based logic analyser through pulseview to use the decoding plugins.

author: tggzzz
author_rank: Super Contributor
timestamp: January 26, 2025, 10:57:45 pm
content: Quote from: OLderDan on January 26, 2025, 10:03:31 pmFor working with i2c, spi, uarts, etc etc, consider a BusPirate5. It also acts as a small PSU, simple logic analyser and even a 0.5MS/s oscilloscope.Benefit: it enables you tocapturetheinformation(i.e. decode the digital signals) and also togeneratethe signals. Hence you can use it to peekandpoke peripherals.

author: nctnico
author_rank: Super Contributor
timestamp: January 27, 2025, 12:01:46 am
content: While those logic analysers may be handy for protocol decoding, I'd prioritize on getting an oscilloscope. An oscilloscope shows you the actual signal. There can be a million things wrong with a signal which you won't catch using a logic analyser.

author: tggzzz
author_rank: Super Contributor
timestamp: January 27, 2025, 12:11:23 am
content: Quote from: nctnico on January 27, 2025, 12:01:46 amThat argument works both ways round.There can be a million things wrong with digital signals that you won't catch with a scope.Consider "long" sequences of two-way messages between a processor and one or more devices on a bus.

author: osmax_br
author_rank: Regular Contributor
timestamp: January 27, 2025, 04:38:31 am
content: Quote from: OLderDan on January 26, 2025, 10:03:31 pmIt is actually really solid idea , thanks !

author: osmax_br
author_rank: Regular Contributor
timestamp: January 27, 2025, 04:50:39 am
content: Quote from: tggzzz on January 26, 2025, 04:21:05 pmWell I actually got a free analog oscilloscope, it is a 20 MHz goldstar os9020g with a function gen , it worked fine 2,3 times and then died , I tried fixing it but it is very complicated circuit (1000s of components) + I get terrified when poking around HV CRT while not having enough experience, I finally gave up and gave it to a friend of mine who repairs board issues on laptops and he told me that he wasn't able to find the problemSince I have very little experience on this stuff (especially reverse engineering and repairs) I concluded that I am better buying a cheap dso since I didn't find any other analog scope in my local areaAlso , do you have any suggestions for a course to get comfortable with repairs and reverse engineer circuits , do you recommend watching "old oscilloscope repair" videos on YouTube or that's a waste of time and you'd be better on a proper course online on Udemy or yt+ I am the same guy who was asking about pursuing electronics as a med student , you always reply on all posts , thanks for your help and time

author: tggzzz
author_rank: Super Contributor
timestamp: January 27, 2025, 09:06:57 am
content: Quote from: osmax_br on January 27, 2025, 04:50:39 amGood decisionQuoteNo, I don't.Be aware that design and repair are very different in all ways. While there is a lot of overlap, it is enlightening to turn up the contrast and consider the differences. Hence simplistically...Repair is about understanding something that already exists. It doesn't require that you understand how the circuit works. It is mainly understanding the symptoms of failure, understanding what typically fails, looking at components carefully to spot gross failures, following test procedures to localise failures, knowing how to repair failures and having the coordination skills. The first of those have a lot in common with doctors, with where the specific published test procedures are the NICE guidelinesThe latter are more nurse/technician skills. It it quite often beneficial to have an older experienced person diagnosing the problem, and a younger less decrepit person doing the repair.Design is about working out and understanding the problem you are trying to solve. You need to understand the maths and physics of the system you are creating, components ideal and non-ideal behaviour, how they are typically put together to minimise the non-ideal behaviour. Beginners worry about how the system will work; professionals worry about how the working system will fail (and how to ameliorate that).EDIT: if you want to have a quick overview of repairing equipment,skimthe blue paragraphs inhttps://emperoroftestequipment.weebly.com/and look at the summary section near the bottom. There are many different types of equipment mentioned, but you will be able to see some recurring themes: electrolytic capacitors and switch contacts.Skimming that is much much faster and more than listening to dozens of talking heads s-l-o-w-l-y droning on in a yoootooob vid. No surprises there

author: tautech
author_rank: Super Contributor
timestamp: January 27, 2025, 09:45:07 am
content: Quote from: tggzzz on January 27, 2025, 09:06:57 amYeah well I started this road with nothing more than a MC meter and unregulated soldering iron !Was gifted a busted 60 MHz CRO and at that time no manuals were available for it online but paper copies from the UK were.Many components were obsolete for that old Telequipment D83 but repaired and serviceable it became and sent me down the road of acquiring any cheap broken CRO I could find, with 1 proviso, full manuals for it must be available !Quickly I had to accept the EHT levels of -2750V were to be the norm and just make the best of it....safely !I fixed many CRO's until discovering the power of a DSO and after repairing a few Tek DSO's and them selling very well luckily enough I was Johnny on the spot to grab an upcoming brand agency......There are times one must be brave......

author: osmax_br
author_rank: Regular Contributor
timestamp: February 02, 2025, 07:24:31 pm
content: Thank you all for your adviceI've decided to get an analog oscilloscope, for around 30$ I got goldstar os9020g 20mhz + 1mhz func genI know that it wouldn't be very useful for my digital work , since I do mostly work on esp32 , i2c , spi ,TFT screens ETC.....However as many mentioned , This 30$ dso is the worst of both worldsSo I would probably get a 10$ logic analyzer in addition to my analog oscilloscopeAny suggestions or adivce?

author: tggzzz
author_rank: Super Contributor
timestamp: February 02, 2025, 08:51:06 pm
content: Quote from: osmax_br on February 02, 2025, 07:24:31 pmThat's a simple instrument - which is beneficial for a beginner.With some imagination and understanding, itwillbe useful for your digital work. The main limitation is that its risetime will be 17ns, so it won't display transients faster than that.Depending on what tests you want to do with i2c etc, a BusPirate5 may be helpful, since it can record and generate a variety of digital bus signals. OTOH, if you are just recording digital signals generated by other devices, then a simple $10 data recorder (plus software for post-processing) may well be sufficient.So, have fun, learn to use your instruments to their fullest, and afterwards you will be in a better position to define what you doand don'tneed in another instrument. I designed and built my first computer (with 128bytes of RAM) using LEDs and a voltmeter, plus an oscilloscope to measure signal integrity on one line.

author: mwb1100
author_rank: Frequent Contributor
timestamp: February 03, 2025, 08:29:07 pm
content: Quote from: osmax_br on February 02, 2025, 07:24:31 pmIf it works, that's a great starting point!Quote from: osmax_br on February 02, 2025, 07:24:31 pmYou've already got the advice on the $10 LA.There's a ton of youtube content about oscilloscope basics (and beyond) as well as using those $10 logic analyzers. So much free resources - start soaking it in.

author: osmax_br
author_rank: Regular Contributor
timestamp: February 04, 2025, 08:41:53 pm
content: Quote from: tggzzz on February 02, 2025, 08:51:06 pmFirst of all , thank you for the advice , I really appreciate itI do intend to start learning analog electronics since it is essential and you can't skip on it -esp32 isn't enough- , I think my analog oscilloscope would be great for thatAlso I do have a question ,I remember you saying that you are a retired engineer in a previous thread , I am really curious how did you learn to use oscilloscope in the 70s and 80s , when there weren't google or YouTube or internet or EEVBLOG to ask peopleI have knowledge about basic usage of the oscilloscope (I did watch hours of tutorials on YouTube) , However there is a pattern , it is either using a DSO therefore not explaining how to do manual measurements on the analog scope , or they do use an analog oscilloscope but they just explain the basics ( nothing beyond how to use time and volt divs and maybe simple triggering, but no more )So I am eager to know your approach on how to learn oscilloscope without internet and it's not so-useful videosPs : I will post this question as a separate thread in the forums ,so don't be shocked to see the same question twice (feel free to copy-paste your reply here over there)Thank you very much in advance

author: tggzzz
author_rank: Super Contributor
timestamp: February 04, 2025, 10:06:48 pm
content: Hm. It was so long ago I can't remember99.9% of yootoob vids are a waste of time, so I can't recommend any.TAoE is as good as any textbook, but I'm sure there are others.It was part of physics lessons at school, so we just learned many things., e.g. how to use a piece of wire, a metre rule and a 2% meter to measure volts to 0.1%. More helpfully, it was a very simple scope, but yours is only slightly more complicated.Basic technique, as with anything, is to RTFM and start with knownMRI scanswaveforms. Twiddle each control and see what happens. But do not attempt to measure mains voltages; that way lies disappointment or worse.Realise there are there are three independent control groups.Volts: vertical channel controls, scale and offset and AC/DC coupling, duplicated for each input.Time: horizontal timebase speed, and triggering.Sweep: how two channels are multiplexed onto a single electron beam.Understand what you ought to see, select appropriate V/div and central offset and AC coupling, seconds/div, auto trigger AC trigger central level. You ought to be able to see a horizontal line in the middle of the screen. Apply signal, and twiddle controls until you see something useful.And when you can't find a trace, there is "beam find"Do realise that there are many classes of scope probe, each with advantages and disadvantages, and they all affect your circuit - minimally if the right class is correctly used. All comment probes have their shield connected to the scope case, and then to protective mains earth.Never ever disconnect the scope's earth, since a mistake could cause the scope case to become live. Some people will claim "floating the scope" isn't dangerous because they have done it and not come to harm. Ignore that advice and them.

author: Fungus
author_rank: Super Contributor
timestamp: February 04, 2025, 10:30:07 pm
content: Quote from: osmax_br on February 04, 2025, 08:41:53 pmUm, yeah. That's aboutallthey did.

author: osmax_br
author_rank: Regular Contributor
timestamp: February 11, 2025, 01:15:48 am
content: Well , guys I have a stupid questionMy analog scope (os9020g 20mhz plus 1 mhz function generator) that I bought is out of calibration, it was in a humid storage environment for 30 yearsHOW DO I CALIBRATE THIS THING WIITHOUT SEPARATE FUNCTION GENERATOR, I have the service manualHowever I only have a dmm (cheap one) and this scopeMy stupid question is : can I do a BASIC calibration using the built-in function gen, or it is a stupid ideaAnd if it is a stupid idea (most probably is) , what is the least expensive thing I can buy to calibrate this thing , should I just do a simple crystal oscillator circuit and call it a day?!!Or just leave it as is since I might do more de-calibration than calibration with my not-good equipmentAlso one more stupid question, when I push times 10 knob, the crt becomes very dim that I barly see a trace , any suggestions about the problem or a guess why it happened?

author: tggzzz
author_rank: Super Contributor
timestamp: February 11, 2025, 11:14:39 am
content: Quote from: osmax_br on February 11, 2025, 01:15:48 amThe principal function of a scope is to show a waveform's shape, not the absolute voltage, not the absolute timing. Analogue scopes are about as accurate as an analogue multimeter, around 2%.To calibrate the vertical deflection, use a PSU as a voltage source, and measure the voltage with a DVM (which should be much better than 2%).To calibrate the horizontal deflection, you need a known frequency. Mains frequency will be accurate to better than 1%, except in exceptional conditions. Do not connect to the mains; just connect a wire to the input and you will see (very distorted) EMI pickup at mains frequency.If your internal function generator is based on a crystal oscillator, then it will be accurate. If, as I expect, it is not then its frequency will be suspect. Use your scope to compare it's output frequency accuracy with the mains using the lissajous figures X Y method; that does not guarantee frequency accuracy at other frequencies.So, creating your own crystal oscillator and digital divider is probably the best route.When the scope's horizontal is *10, then it is sweeping ten times faster (doh!), so only 10% of the electrons are hitting each spot. That will make it dimmer.

author: tunk
author_rank: Super Contributor
timestamp: February 11, 2025, 12:26:49 pm
content: Quote from: osmax_br on February 11, 2025, 01:15:48 amPlease don't double-post, and this has nothing to do with the DSO510:https://www.eevblog.com/forum/testgear/calibrating-analog-scope-with-minimal-equipment-only-built-in-generator/

author: osmax_br
author_rank: Regular Contributor
timestamp: February 11, 2025, 01:08:18 pm
content: Quote from: tunk on February 11, 2025, 12:26:49 pmGot it boss , sorry for the inconvenience I madeI am kinda new to the forums