5 ms·

I love these little stories, they always make me want to go out and buy a proper oscilliscope so I can start my own adventures. I'm surprised by how simple and

• slig 9y ago
  I'm an electronics enthusiast (play with it on weekends) and the Rigol DS1054Z oscilloscope (it's the same used by OP) has a really good cost/benefit, and it's also hackable.
  • tomxor 9y ago
    Yes I was just looking at it, £300 seems pretty reasonable. A while ago I was looking at old used stuff but even they are in the thousands. Thanks for recommending it, it's nice to know some HN readers are using it because I don't really know what to look for in an oscilliscope :)
    • cushychicken 9y ago
      I know Rigol was doing a promotion around the holidays where they'd give you expanded bandwidth, serial decode/trigger, and a few other goodies at no charge. Of course, you can always just see about taking matters into your own hands (http://gotroot.ca/rigol/riglol/ http://gotroot.ca/rigol/riglol/)
      • watersb 9y ago
        Test Equipment dot Net is running the Rigol promotion through June: https://www.tequipment.net/rigol-promotions-and-offers/ https://www.tequipment.net/rigol-promotions-and-offers/
    • joshvm 9y ago
      If you want a cheaper and more portable solution, have a look at Picoscope (UK). Don't believe the guff about USB scopes being garbage. These things have plenty of bandwidth and it's really nice being able to carry around a scope in your pocket. Unless you do a lot of high speed IO, 25MHz covers pretty much everything (most 8-bit Micros top out at 20MHz, some go to 48-50MHz). Even the 10MHz version is fine if you were just doing audio work or slower digital stuff. For £300 you could get a 50MHz 2 channel scope (at 0.5Gs/s). If you want 4 channels you're not going to beat the Rigol for price, but portability matters sometimes (other times being able to monitor every SPI line simultaneously is a godsend). I have a Rigol DS1104Z and a Picoscope 2205A, I've used both extensively. Plus you get a lot of nice features in the software (which is cross platform), including serial decoding for free. Most of them have a signal generator built in too.
      • tomxor 9y ago
        Wow, it also has drivers for the raspberry Pi ! https://www.picotech.com/support/topic14649.html https://www.picotech.com/support/topic14649.html This pairing would make for a trully tiny all in one oscilliscope, i'm tempted to get a picoscope and a tiny LCD just for laughs: project #1
        • tridentlead 9y ago
          You may not want to do that. The sampling rate is very important on a scope, especially for analog signals because of Nyquist.
          • joshvm 9y ago
            I think the idea is to use the Pi purely as a display. Picotech's scopes tend to be well specced with regard to analogue bandwidth/sampling rates - around 5x Nyquist typically.
          • tomxor 9y ago
            Hmm, I was expecting the sampling frequency to have been made independent of the USB bus, (i.e for the sampling to occur purely on the picoscope itself and data merely relayed over USB). I don't even know what the frequency limitations of USB are I just know it's capabilities are highly dependent on the host so relying on it for precise high frequency sampling seems like a bad idea, and if that is the case for the picoscope then you are correct, I just find it a surprising design decision. Am I wrong in thinking this? or are you referring to a different reason?
            • joshvm 9y ago
              Yes, all the sampling is performed on the Picoscope and then streamed over USB. This is something that you need to grok when using scopes: you're capturing (often) a teeny-tiny snapshot of time. The waveform on your display might be 50ns wide. You certainly can't process this data in real-time using your eyes (that'd be 20 million frames a second). So you're not seeing a continuous signal, you're seeing short snippets of your signal separated by some dead time. The majority of this dead time is probably just writing to the display. You're not pushing pixels to the display at the sampling rate of the scope, otherwise these would be some of the best monitors in existence! Usually scopes are triggered somehow and you'll be sent waveforms, typically centred on the trigger point, at some maximum frame rate. So you'll see a little bit before the trigger and a little bit after. Most scopes let you vary the trigger offset, e.g. if care more about stuff that happens before or after. Using an oscilloscope well is all about the triggering! The scope will have (a) a max. sampling speed and (b) a fixed size sample buffer. You trade off both. You can sample really fast for a short period of time, or slower, but see a longer time period. If you want to see 'all' the signal, then you can set the timebase to something long - e.g. 100ms/div. That's useful for seeing slowly varying signals, but you'll lose resolution. A scope with a nice big sample buffer will let you zoom in on a signal once its been captured. Once the buffer is full, the scope has to transfer that data to you, either directly to a screen or over a serial connection. Unless you're in single shot mode, this process will repeat every time the trigger condition is satisfied.
• carrigan 9y ago
  Thank you for the kind words! I will echo slig and say that I have been really happy with the Rigol DS1054Z so far. I love that you can build a really capable electronics lab at home in 2018 for less than $500.
  • joewee 9y ago
    Any guides in getting started with an oscilloscope?
    • himom 9y ago
      eevblog has an extensive collection of oscilloscope vids.
    • rasz 9y ago
      https://www.youtube.com/watch?v=rTPhuRQBmLQ https://www.youtube.com/watch?v=rTPhuRQBmLQ
  • jjoonathan 9y ago
    Micsig scope tablets are great too. Similar price and specs but they're also battery powered and portable!
• yellowapple 9y ago
  In this particular case, it's not too surprising. PC-connected barcode scanners traditionally use a relatively-ordinary RS232 (or USB nowadays, usually with support for either depending on which cable you're using), and almost always just pretend to be ordinary keyboards. I'd be more surprised if it deviated from that at all. I was kinda hoping that this would be someone porting Nerves to run on the barcode scanner itself; quite a few of these scanners actually have reasonably-powerful ARM cores (especially once you get into the 2D scanners).
• himom 9y ago
  Watch EEVblog and bigclive on YT for oscilloscope advice.
  • DanBC 9y ago
    bigclive works on electric / electronic stuff, and he's sometimes a bit sniffy about cheap hobbyist kit. (Fair enough when he's talking about things you use with / on mains electricity where there's a risk of death.) For RS232 any 'scope is going to be fine, even a chinese clone knockoff or an ancient second hand scope.
    • gh02t 9y ago
      For decoding serial one of those $5 logic analyzers is more than sufficient, you don't really need an oscilloscope at all. I don't really like using protocol decoding on my scope unless I need to correlate timing with an analog signal because it's tedious to set up and use for a simple digital signal. https://www.aliexpress.com/item/New-Arrival-USB-Logic-Analyzer-24M-8CH-MCU-ARM-FPGA-DSP-debug-tool/32810021495.html https://www.aliexpress.com/item/New-Arrival-USB-Logic-Analyz...
      • slig 9y ago
        It's worth noting that some of those cheap logic analyser only work with pirated versions of expensive logic analysers software.
        • voxadam 9y ago
          While cheap knockoff analyzers often ship with pirated software (e.g. Saleae) many, if not most, work equally as well with the open source Sigrok software.
          • gh02t 9y ago
            Saleae gives their software away for free, there's not any need to pirate it but still using their software is morally shady IMO because they put a lot of effort into it. I prefer Sigrok anyway, even with the actual Saleae analyzers. Also worth noting that Sigrok loads the analyzer with open source firmware, you're not using any pirated code. The hardware is basically a clone of the original Saleae logic analyzer, but the Saleae hardware is just a standard reference implementation of a cheap Cypress chip so that doesn't really bother me.
• ChuckMcM 9y ago
  Having an oscilloscope is great, and it needn't be thousands. For general tinkering and exploring I picked up the Digilent Analog Explorer 2 with the Ham Radio bundle[1]. They had a coupon deal where 'hamradioworkbench2018' would unlock a $100 discount. Not sure if that still works. While it is a USB scope (so you are dependent on your PC/Laptop for a display) it includes some other useful bench top tools. Used scopes in the 100 - 200 Mhz range from the 90's are often pretty inexpensive and can usually be calibrated and repaired. This is especially true of the Tektronix 465 and 475 series which were sold in huge numbers. While not as crisp as a digital scope they work well and can be found (at least in the Bay Area) for $50 - $100. About double that on ebay. The Rigol folks really pushed the price point hard and their DS1054 and DS1102D series are fairly common and inexpensive at $300 - $500. Scrounge around HAMFests or surplus liquidators and you can often find a deal if you know what you want. [1] https://store.digilentinc.com/ham-radio-workbench-bundle/ https://store.digilentinc.com/ham-radio-workbench-bundle/