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Ask Slashdot: What's On Your Hardware Lab Bench?
50000BTU_barbecue writes "I made a comment a few days ago in a story basically saying the oscilloscope is dead. While that's a bit dramatic, I've found that over the last 20 years my oscilloscopes have been 'on' less and less. Instead, I use a combination of judicious voltage measurements, a logic analyzer and a decent understanding of the documentation of the gadget I'm working on. Stuff is just more and more digital and microcontroller-based, or just so cheap yet incredibly integrated that there's no point in trying to work on it. (I'm thinking RC toys for example. Undocumented and very cheap. Doesn't work? Buy another.) While I still do old-school electronics like circuit-level troubleshooting (on old test gear), that's not where the majority of hobbyists seem to be. Yet one thing I keep hearing is how people want an oscilloscope to work on hardware. I think it's just not that necessary anymore. What I use most are two regulated DC lab supplies, a frequency counter, a USB logic analyzer, a USB I2C/SPI master, and a USB-RS-232 dongle. That covers a lot of modern electronics. I have two oscilloscopes, a 100MHz two-channel stand-alone USB unit and a 1960s analog plug-in-based mainframe that is a '70s hacker dream scope. But I rarely use them anymore. What equipment do hardware folks out there use the most? And would you tell someone trying to get into electronics that they need a scope?"
need a pullup? a scope will show you
have fighting drivers? insufficient path to ground? noise on the rails?
if you're doing anything aside from poking at other peoples stuff thats cheap and
disposable, you need a scope
On my lab bench for 15 years:
Oscilloscope and Multimeter
If you're actually designing from scratch a new digital PCB, you can do without a lot of stuff but a 2GHz or faster O'scope is essential:
1) Debug of Switching Power Supplies [could get by with 100Mhz scope for this...]
2) Debug of high speed digital AC effects [line impendance, termination etc]
3) Verifying Setup / Hold of interface busses
4) Determining margin on variety of interfaces
Seriously. First tool a high speed scope... And Garmin International: 300MHz is for yesteryear, today most engineers need at least 1GHz to get by in digital design
2nd tool: a Good DMM
3rd tool: A thermal camera for when things go dreadfully wrong..
Other tools are gravy... [Though clearly a power supply is non-negotiable...]
Every conceivable adapter, gender-bender, splitter, and breakout box under the sun.
Guiding principle: For every connector form, there is an equal and opposite requirement.
Scruting the inscrutable for over 50 years.
10" table saw
craftsman drill press
Makita battery charger
2 vise, 1 with soft jaws
3 levels
bottle opener
I want to delete my account but Slashdot doesn't allow it.
you do use it, therefore it's dead.
I declare the Superbowl dead becasue I don't watch it anymore.
The Kruger Dunning explains most post on
I feel pretty good about that.
Much better than I ever could if I had no unfinished projects or any to start.
The beauty of a pile of parts and doo-dads scattered among various boxes is you always have something you can do if you have nothing else to do.
And there's always room for one more.
A feeling of having made the same mistake before: Deja Foobar
On my office work bench:
Binocular microscope
soldering station
solder
flxes
large magnifying glass with light ring
project boxes full of SMD parts
tweezers
side cutters (dikes in the US)
scrap wire
storage scope/logic analyzer
power supply
In the other room:
cheap chinese reflow oven ,machine
cheap chinese stencil jig
(and if I can finally persuade my wife) cheap chinese pick and place
At this point I have to point out that almost all my best tools these days are cheap and from China, mostly bought off of aliexpress at prices maybe 10% of what I used to spend buying from the US - stuff I'd never ever have considered buying for myself 2-3 years ago. In this case being cheap and from China doesn't mean low quality or non-functional, quite the opposite.
Right behind a decent handheld DMM, a scope is about the second piece of bench gear I recommend to anyone. Old used digital scopes are so darn cheap anymore (my TDS340A that I've had for 18 years can now be had for $250-400 on eBay), and they really help you visualize what's going on in the circuit. I'd give up just about every other piece of real lab gear I own to keep my scope, because the rest is either for specific past projects, or is just nicer to work with, but could be substituted with lesser quality gear. There's no substitute for a decent scope in my opinion, but I do a lot of pure analog or serial stuff where being able to capture and stare at a waveform can go a long way towards finding a problem. Plus, all that digital eventually gets down to the real world, where ugly analog problems eventually rear their head again (slew rate, parasitics, transmission line uglies, etc.)
I'd bet I have my scope fired up 80% of the time that I'm not strictly working on firmware, and probably 20-30% of the time that I'm just working on code.
My main bench gear:
- Tektronix TDS340A scope
- HP 33401 bench DMM
- A couple various portable DMMs - one Fluke 87V, a couple cheapo Chinese, and a couple super cheapo Harbor Freight
- Saleae Logic16 logic analyzer (awesome tool, by the way...)
- Four old Lambda LLS lab power supplies
- Old HP 3310B function generator
- For soldering, a Hakko 936 iron, modified toaster oven for reflowing, and a hot air rework station
- a pile of other strippers, crimpers, pliers, screwdrivers, tweezers, magnifiers, and assorted hand tools including my favorite Xcelite MS-545-J cutters
- USBtinyISP for programming AVRs, Picstart 2 for programming PICs
- Mendelmax 3d printer for printing out parts and prototypes
- And a pile of other stuff to make the work more pleasant - my dev PC, a beer fridge, a TV, a Blu-ray player, a mythtv frontend box, a laser printer, bins of electrical and mechanical parts, datasheets I use frequently, etc.
I like all of the stuff, and wouldn't trade any of it, though I keep thinking about one of those new Agilent DSOX2024 scopes. I probably won't, though - my old Tek does well enough, and it has a great deal of sentimental value for all the years and projects we've done together. The only thing I'd really like is waveform capture on something that wasn't a 3.5" floppy...
I'm the author of Teensyduino, software for an Arduino compatible board.
I sometimes use my Agilent scope when developing or porting Arduino libraries. Sometimes I just want to check the relative timing of stuff, so I'll set a pin high or low at some point in the code, then capture with the scope to see if the code is taking a long time. Often it's surprising how fast, or how slow certain code can be, and pretty often it's relatively easy to discover and fix performance problems. You can do quite a lot by normal software debugging processes, but pretty much all those approaches involve running the code much slower. When you're debugging real-time code, like libraries that synthesize waveforms by bit-bashing or tricks with timers or DMA channels, there's really no substitute for a good scope.
But admittedly, this is a pretty narrow fringe. Most people probably don't do this sort of low-level coding.
PJRC: Electronic Projects, 8051 Microcontroller Tools
And an intern.
It grants this wonderful ability to be organized and to know what is what and that is what keeps the rest of my lab working.
I prefer self-organizing chaos. I use hashed buckets . . . Least Recently Used stuff sinks to the bottom of the buckets. Stuff I need a lot floats on top. Plus, I have a concept of RAID . . . since I can never find stuff, I have at least two of everything.
And when I really need to dig deep . . . it's like Christmas! I find all kinds of stuff that I never knew I had or used! Wow, I should try out that PCMCIA Token Ring card, or that USBVGA adapter cable!
Schroedinger's Brexit: The UK is both in and out of the EU at the same time!
Because of the work I do I have a collection of test gear I've accumulated over the years. The things which get the most use? The variable DC power supplies, the multimeters, and yes, the oscilloscope.
The oscilloscope occupies the spot right above where the target sits most of the time. I find it to be very useful to troubleshoot digital realm issues, including things which one would seem to think a logic analyzer would be perfect for. If I'm having a hard time getting two things to talk, say over an I2C bus, I reach for the scope first, since I can see whether or not the lines are toggling as expected. And if they're at the right voltages, and so on. I can also tell if the clock edges are correct and similar. This accounts for like 99% of the problems I run into that I need an external test instrument for.
Yes, I do have various logic analyzers. Two USB ones, a big one I'm about to sell on ebay, and a few more specialized ones (serial protocol analyzer, USB protocol analyzer). Most of the time they sit in their cases on the shelf.
-forrest
... when I am interested to know how one thing works
... when I just want to diagnose the inner-working of a gadget
I do not care how cheap that thing is, I'll power up my scopes
I do not care how cheap that thing is --- if I have to know I just have to know
I won't do the "oh, it's so cheap I'll buy a new one when this one conks", oh no, that's not the way I operate.
When my curiosity calls, I have to satisfy it.
Muchas Gracias, Señor Edward Snowden !
First of all what I'm doing: I'm designing industrial embedded hardware, using funky data busses and high-resolution ADC's. I do all the hardware design, layout, prototype fabrication, and *all* firmware and host-side software. I'm pretty much a one-stop shop for this project (and the only engineer on it...). The hardware is all "slow" stuff at this point, with the fastest clock being the 32MHz driving the 8-bit microcontrollers scattered throughout the system.
Panorama of my office
First off I've got my computer in the "middle", nothing special except the monitor's on an arm to free up desk space. A second monitor to the right is used for debugging consoles etc. (and WoW). Several USB hubs are scattered around (some mounted) for use by both tools and the product under development.
To my left up on a shelf I have a (rented...) Agilent MSO-X 3014A scope, 4-channels plus 16 digital, unfortunately only the 100MHz version. I have a second-hand cheapy 5MHz signal generator next to that for occasional use (impedance checking etc). A simple Protek 3006B power supply (Fry's?) handles everything I can't run off USB 5V or from an LDO.
A Saleae Logic and Logic16 do quite a bit of work for me, and there's the occasional use of a BusPirate. An AVR-ISP MkII handles direct programming of the microcontrollers when possible, while the vast majority of my programming and test jigs are built around my own STK500v2 implementation multiplexed with serial debug.
To my immediate left is the main project space, while to my right is space for whatever projects crop up and don't have to have direct access to the scope.
In the window against the desk would be one or both cats.
To the far left is my soldering environment, which includes a regular temp-controlled soldering iron as well as an Aoyue Int968 hot-air soldering station (with its own soldering iron). A $25 toaster oven is used for reflowing most simple boards. Bins of loose parts cover the shelving above.
Behind me is a desk that holds a "proper" reflow oven, albeit the cheapo $300 unit from eBay, as well as a rework station of the kind used for XBox repairs (some of my boards have a *lot* of thermal mass that hot air alone can't handle). Reels upon reels of SMT parts are piled under the desk...
Lighting is provided by 2x 60/meter LED strips that side-fire to each side along the camera-window axis, plus an overhead Ikea quint-MR12 set over the main workspace when needed.
GStreamer - The only way to stream!
LAs have become too much.
Often I want a lot of channels, but to capture diagnostic data specifically formatted for output to a diagnostic port on the chip. So I don't need a $100K Agilent mainframe LA setup. I just need a synchronous FIFO that can be triggered that a PC can read.
Since such things are not really out there, you just hack it together with an FPGA. So it's product+FPGA dev board+a few wires+a usb PC connection.
The DFX circuitry is all on chip. You just want to get at it.
I should use this sig to advertise my book ISBN-13 : 978-1501515132.
As an electrical engineer, I have to say, some things are best done in the analog domain. A good oscilloscope is a must for checking low level sensor signals, amplifiers and filter performance.
Had a bad week, so all that is on my workbench right now is a big freaking hammer and some debris.
This is a hacked account, for which the owner can not be held responsible.
I have a $40 digital microscope from eBay.
It's top heavy, so I inserted a rare earth magnet in the base and covered over with felt. It now solidly sticks to metal surfaces. It's also manual aim and manual focus, with no staging. This can be a pain for certain applications.
I use it for surface examination when I'm experimenting with process - such as processes for making PCBs. Here's an example. I take pics of the final result and create a LibreOffice word page describing the details of the process and how well it worked out. This goes into my lab notebook.
Here's another example.
For medium magnifications it's pretty useful, and I like being able to grab digital pics on my computer and annotate, save notes, and send to people (like in the post above).
A sonic screwdriver. Only tool I ever need.
Heh. I've got an old SGI Octane running IRIX 6.5.30 UNIX. Great fun. With a buss that has ~3ms between any two I/O points and optical digital audio I/O, it's still quite useful for some audio recording/processing/storage tasks related to home recording studio work.
I also design and build vacuum tube guitar amplifiers, where my '70s-era two-channel analog 60mHz delayed-sweep Tektronix 453A 'scope still serves me well. It used to be used on avionics out on the tarmac in Nebraska and then Michigan, in winters & summers, baked and frozen, buried in snow and half-submerged in water, and has been blown hundreds of feet multiple times across the flightline tarmac from prop wash and jet exhaust and still functioned like a champ. Worst result was it lost some paint, gained some scuffs, and needed re-calibration. Not even the handle broke.
Many tens of thousands of years from now when humans are long gone and aliens are doing archaeological digs on Earth, they'll be shocked when they dig down, following a faint energy signal, only to find an old Tektronix 'scope still displaying a trace from when the tech left for the last time and forgot to turn it off. :)
Strat
Progressivism (aka US 'Liberalism'): Ideas so good they need a police/surveillance-state to enforce.
I think the primary thing being left out of all the lists is the knowledge gained by experience. If you don't have it, nothing will replace just doing it yourself. Good tools are nice- but face it- EVERY SINGLE PIECE OF TEST EQUIPMENT LIES. Or maybe just doesn't tell you everything. Experience helps in figuring out what really matters. A 100 MHz analog scope is nice, but useless when it comes to a parasitic 1GHz oscillation. A logic analyzer is great, but misses a lot if two outputs are in contention.
The tools I use depend on the job I'm doing. Debugging serial comms? I love my Saleae. Looking at a fast edge? DSA602A.
That said, here's some of my vital lab equipment:
Saleae Logic
Tektronix DSA602A
Temperature controlled soldering Iron
Stereo Microscope
Credit Card
ebay
Whether or not you NEED a scope for your every day work in electronics may not matter as much as the insight it gives you to see the theory you learned played out on a scope trace. An analog scope is best for really getting an insight into the fact that all the theory and math actually does something in the real world.
I am an old geezer and have been doing electronics from the days of vacuum tubes and point to point wiring to the current world of processors, ASIC's, and FPGA's and any time the analog world meets the digital I wouldn't trust any instrument more than a good scope. Your mileage may vary.
but that's a fair accusation, because I don't really.
80-90% of things can be shipped off to software where it's delightfully easy to trace/probe/debug things, and you have a functional unit which is infinitely malleable. What you can't do in software most realistically ends up in an FPGA, where really you're just debugging your VHDL/Verilog, and the simulator is your new best friend for 80-90% of the cases. When the simulator is a lying piece of junk, 80-90% of the time all you need is a good logic analyzer...
But there's still that ~1% of the time where software and/or digital logic just didn't behave right. Something analog is either necessary (e.g. maybe you're doing something actually useful, like driving a motor, rather than just flipping bits), or analog is making your life miserable.
Even professionally, I've found a 2-channel 50 MHz analog scope to be a godsend in some cases; of course, I like my 4-channel 1GHz digital scope more :) If you end up interacting with anything real and physical, or if you you move beyond merely debugging black boxes and into building your own stuff, even a crappy scope can give you information you simply can't get any other way. Who cares if it is uncalibrated and wildly inaccurate if a surplus scope will still show you the shape of what is going on, with all of the noise and ringing and transient under-(and over-)voltages and double bounces and cross-talk and odd harmonics and wtf why was that capacitor in the wrong bin this RC constant is borked and yep that part's dead and oh shit bad solder job and all the other crap that makes me happy I get to spend most of my time in nice clean software?
If you're just putzing around, sure, a DMM will do ya. But if you're actually building something new (even something simple), you need a scope.