mini digital storage oscilloscope review

I just got in the decidedly-cute DS203 Mini DSO (digital storage oscilloscope), weighing in at a mere 80 grams. We can reasonably guess from MiniDSO.com’s website that English is a second language for them. From what I understand, this is an open-source project so it will be fun to see what I can do with this.

SainSmart
K1, K2, K3, K4 & NAV A, NAV B across the top

Open Source

From what I’m reading in an online PDF, you can tether this to a PC and it appears as a USB drive, allowing you to make some modifications to the system itself. There appear to be examples for updating the splash screen logo and downloading/updating the application itself. Since this is likely some sort of Linux as the operating system then that will mean that I might be able to hack apart the update to find out what’s inside.

Precision

Looks like there are six adjustable potentiometers “under the hood” to allow you to calibrate it for accuracy. Most full-sized scopes have this feature but usually only about two of these adjustments, to be honest.

Accessories

It was fully assembled in the box although the online PDF suggests that there was a time when the customer was asked to fully put it together. This one included two probes (1X, 10X) which is pretty generous given that they can be as much as $30 each. It includes a small hex wrench for opening the back (access to those potentiometers). And finally, there was a tri-fold card with the barest of instructions possible. Here’s an example of a third of the instructions:

Turn on the power, enter the main page of the oscilloscope. Place in the standard signal (e.g. square wave 1 KHz, Vpp = 5V), insert X1 probe’s MCX end to CH A or CH B, and the probe to “WAVE OUT”. Check if the measurement value and the standard value are equal, calibrate if different.

Okay, I know enough about oscilloscopes to know what they mean here. I’ll translate this into English-geek for you:

Connect the X1 probe to the CH A connection, power on the oscilloscope and wait for the main screen to appear. Remove the probe’s cover to reveal the bare tip, putting this into the center of the  “WAVE OUT” port. Press Key 4 until the side menu is selected then use NAV 2 to select V1 from the options. Use NAV 1 to adjust the horizontal line until it coincides with the top part of the square wave, noting the voltage—as now measured—at the bottom of the screen. If this voltage is different than the reference 5.0V from the signal generator, then calibrate the meter by following these steps…

etc

At least that is the standard routine on a full-sized oscilloscope. I guess what I’m trying to say here is that the online PDF and tri-card documentation are pretty laughable and aren’t enough for the average person to learn how to use it.

On-screen Menu

The menu is pretty difficult so far. It’s clear that NAV A and B are used in selecting different values and moving from one place to another. K4 appears to move between the top set of menus to those down the right side of the screen.

Progress

After two full evenings playing with the interface, I’m beginning to understand some of the strange logic. Some of the hidden functionality is found when you press down on either the NAV A or NAV B sliders. It’s lost on the average person that these left/right sort of controls actually can be pressed as well. This opens up the missing features which were formerly lost on me.

So now, I can put an output wave on the screen (CH A–inserted probe to WAVE OUT), adjust the signal to a square wave of 20 microseconds in width, add a single reference voltage V1, hide V2 (and Channels B/C/D), adjust the T1 and T2 reference lines to match up to the waveform’s leading/trailing edges and then reference the delta at the bottom of the screen. Given the complexity of this as compared to the absence of a working manual, I’d call that rocket science.

The next step will be to attempt to calibrate it with a known good 5V power supply which I’ve just adjusted, having measured that with a good-quality multimeter.

Thoughts

I’m torn between moving ahead now with my own work and writing a useful how-to manual for this oscilloscope. It’s a shame that someone’s not written a good tutorial yet for this.

Update

And of course, I began working on rewriting a useful manual for this.

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moore’s law and stuff

Just ordered a very cool oscilloscope by SainSmart to work on the Raspberry Pi/NeoPixels project. My last clunky, large oscilloscope from eight years ago easily weighed in over 20 pounds to heft it around and cost over $400 (minus shipping of course). The older one took up an entire workbench in footprint. The new one weighes about 80 grams without its battery, fits in your pocket and costs less than half that price.

Moore’s Law is the observation that the number of transistors in a dense integrated circuit doubles approximately every two years.

Keep in mind that Moore wrote this guesstimate in a paper back in 1965, long before the globalization effect of electronics took the market by storm.

SainSmart

If he envisioned things like this back in the sixties then he was cleverer than myself. Although I grew up on The Jetsons and just knew that we’d be flying our cars to work by the year 2000, this miniturization craze wasn’t something that I would have dreamed up. There’s was a certain limit to how tiny things could be due to the size of our own hands being a constraining factor. Someone still had to assemble it, right?

Tiny is the New Black

Speaking of which, I recently had to buy the tiniest screwdriver at Frye’s to remove the tiniest screws I’d ever thought possible in a commercial product. These are called Pentalobe screws from penta (“five”) and lobe (“times harder to find than a grain of sand if you drop it into your carpet”). Seriously, don’t drop these screws.

SONY DSC

Imagine real life for a moment and things aren’t zoomed in for your convenience.

Whatever you do, shy away from the laser-etched metal kits of Star Wars figures that require that father from “Honey, I Shrunk the Kids” fame to get his kids to put them together for you. This project will make you angry at yourself for being unable to do something that humans can’t do:  build tiny things with our big hands.

R2D2

What would it take to work at an Apple factory these days? There’s little chance that these are put together by humans, I’m guessing.

iWatch

What sucks is trying to work on an iPhone these days, especially if you have to replace a component. I keep buying tinier pointy tools to assist in the removal of and replacement of these type of modules.

I try to develop good working skills which help to prevent the loss of tiny things. Some of these are so small that the slightest breath could send them across your workbench. My current trick is to use tape on my workbench so that tiny things will stick to it.

And of course, someone had to build the wearable ring computer which probably wants to be used in digital signing or two-factor security, I’d guess. Or if you work for the Mafia, maybe you just sign someone’s face with this. It looks like it would hurt, tbh.

16labs-ring-computer-2

And then there’s the contact lens monitor since we don’t have enough eye fatigue yet by the end of an average business day.

contactlens

If you thought that nanobots were a thing of science fiction, guess again. These are robo-scallops which are designed to move around inside your body. Because as we all know, scallops are so good at healthcare. Anyway, since they’re powered by an external magnetic field, they don’t require batteries. That’s a good thing since I don’t have an AAAAAAA batteries lying around.

micro-scallop-1415079090210

It’s almost as if that finger is looking at me with tiny, tiny eyes. Now I’m creeped out.

the sophistication of phishers

Phishing is an activity where you try to con someone out of their private information (like credentials) and these people are too darn clever. I just got a perfect rendition of Apple’s classic email notification that my Apple ID had been used on a Windows 10 computer with Chrome over an IP address in Israel and that my account is now locked. It’s enough to make you panic and click the link they provided.

The Psychology of Fear

Of course, fear is a prime motivator. “ONOZ! I’ve been hacked!” No, actually. Someone just has your email, which you could have seen from the “Undisclosed Recipients” distribution list.

And yet, it was enough to make me go to a different computer, visit Apple’s website and confirm that my Apple ID wasn’t locked out and it’s only being used on my own devices.

Apple’s Lack of Customer Support

For a company that makes as much money each year as Microsoft, Oracle, Google and Adobe combined, you’d think that there would be room in the budget to support their customers.

showmethemoney

In fact, I just spent many moments trying to let Apple know of the sophistication of this phishing attempt, to identify the culprit(s), their website(s), email address(es), etc. No dice. Apple’s doing such a good job of blocking customer requests that I decided that the best way to get the information out there was to blog it. Pretty sad, really.

too much fun

My two packages arrived today at the post office so I just hauled in all the loot from this earlier post in which I’ve purchased some new toys.

Raspberry Pi Zero W

The photos from their website don’t really describe how truly small this computer is now. They’ve somehow managed to stack the RAM on top of the microprocessor to save space. As I’ve apparently ordered the wrong video adapter cable, I’ve got a trip over to Best Buy Frye’s Electronics this evening so that I can sort that one out. I need a female HDMI to DVI, in other words. Otherwise, I’m still pretty stoked. Since there’s only one micro-USB I think I’ll temporarily need a small USB hub while I’m at it.

PiZero

NeoPixel Ring

This arrived as well, all four of the segments but it was lost on me that I’ll need to solder each of them together. Fortunately, I have a soldering iron here somewhere. :looks around: I’m certain of it.

COZIR CO2 Sensor with RH/Temp

And in the other relatively BIG package is the relatively small sensor package. No wonder they charged me $21.88 to ship this to me. Seriously, it weighs about an ounce.

And it looks like I’ll need a 2×5 jumper to attach this over to the Raspi, with a solder-able header for that, too.

Update 1

Alright, I’m back from Frye’s with a handful of stuff and I’m back in business. The video adapter allows me to see what’s coming out of the Raspberry Pi Zero W and the micro-USB hub allows me to hook up a keyboard and mouse to talk to it locally. A first install with the Raspbian Jessie Lite image resulted in a terminal-only configuration (I must have been in a hurry and didn’t read the differences on their page) so a second install of Raspbian Jessie with Pixel was just what it wanted: a full desktop experience.  If I get some time this weekend I’ll try to have it talk to either the sensor or the light ring.

Update 2

I just managed to solder together the NeoPixel ring. Due to the size of the electrical pads on the ends of these, I’d suggest that this falls into the catagory of advanced soldering and not to be taken on by the average person.

NeoPixel
These are not my lovely hands.

Additionally, I’d say that this feels a bit fragile in the area of the soldering joints between each quarter-circle. I’m going to suggest that anyone who incorporates one of these into their project needs to seriously think about ways of making this more stable/reliable since the soldering joints between them are tenuously-small.  (Imagine three distinct electrical connections across the tiny width of this thing.)

What I also found is that there isn’t anywhere to clamp a hemostat for soldering these jumpers since the LEDs run all the way to the end where the connections should go.

I did add an inline resistor as Adafruit suggested to lower the input voltage or perhaps to lower start-up voltage spikes.

I managed to re-purpose a nice external 5V switching power supply that should drive all the LEDs nicely. It was left over from the supercomputer project when I swapped in a USB-based charger instead for that. Amazingly, Adafruit suggests that those 60 LEDs need a whopping 3.6A of power to drive them. I’m guessing that reality is more like 1A but I’ll play this safe. Per Adafruit’s suggestion I included a 1000 µF electrolytic capacitor across the output voltage to protect the NeoPixels.

VGD-60

So I’m prepped to do a final test of the NeoPixel ring for power and functionality on a standard Raspberry Pi 3 rig (since it sports an actual header). Once I’ve coded a test and verified that it works then I’ll take the soldering iron to the Raspberry Pi Zero W and wire it in with a quick-connect.

headerwire

I’ve now got the Raspberry Pi Zero W booting with just the power adapter. Note that you can rename its hostname, toggle on the VNC Server, adjust the default screen resolution to your liking and then—in the Finder program in OS X—open up a remote session to its Desktop with vnc://pi@hostname.local, for example. Or, toggle on the SSH Server and connect from a Terminal session with ssh pi@hostname.local.

Have I mentioned how awesome it is to have a fully-functioning computer for $10 (plus $6 for the micro SD)?

And now the power supply is completed and wired to the NeoPixel ring. Everything’s set for 5V DC in at the moment but I may try to adjust the input voltage down to 3.3V later for technical reasons. (The NeoPixels are designed for the Arduino and its output data voltage is 5V whereas the Raspberry Pi is only 3.3V. By adjusting the input voltage down then it makes a 3.3V data line look bigger than it is. There are other tricks like adding a 3V-to-5V data inverter chip but I’d like to avoid that one if possible.)

PowerSupply

Update 3

I’ve smoke-tested the power supply/ring combination and it’s looking good. To make things easier for this step, I’ve now setup a surrogate Raspberry Pi 3 for testing things but since I only had a leftover 4GB microSD, I was forced to use the no-desktop “Lite” Jessie version of Raspbian. But that’s now ready and I’ll likely have some time this weekend to do a basic blink test.