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?"

Comments

thats silly

[Anonymous Coward]

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

Re:thats silly

[gweihir]

Indeed. If you do not need a scope, then you do not do any real electronics. For some debugging, there is no replacement. Especially for gaining understanding, nothing can replace it. And yes, mine is not on so often either, but for some things there is no replacement and I need it. Also, with a nice digital scope, you can document things by placing screen-shots on the web or into documents.

Re:thats silly

[wavedeform]

For most digital work these days, you really just need a logic analyzer.

Unless your logic analyzer can show you ringing or capacitance / inductance problems on the digital signal lines, this is not really true. "Digital" signals on a circuit board are analog after all, and are subject to a lot of the same gremlins that plague an all analog circuit. This sort of thing doesn't always matter in a digital circuit, but you need a good scope to find them when they cause problems.

Re:thats silly

[bob_super]

If only I had mod points...

Trust me on this one, you can spend your days in simulations all you want, but that >100Gb/s board isn't going to work if you can't check your rails and the jitter on your reference clocks.
If all you do is program other people's boards/systems, and they have enough shelf life already to be certified to work properly, then a scope isn't useful.

If you want to be near the cutting edge, you shouldn't fly blind.

Re:thats silly

[emt377]

Obviously, anyone designing electronics and building prototypes needs a scope. How else would you know what the ground plane looks like? Clean or noisy? Even a cheap 20-40MHz scope will show dirty signals as "fussy", and will allow identification of beat patters and cyclic issues... I suspect the OP doesn't actually do any board design, because if he did he'd be using his scopes and spending big bucks on really good ones.

Re:thats silly

[Almost-Retired]

If you do not need a scope, then you do not do any real electronics.

I would say that's just a bit over-broad. For most digital work these days, you really just need a logic analyzer.

Having said that, if you are doing just about anything but "pure" digital work, do do pretty much need a scope.

I don 't think its a bit over-broad. I've had a scope probe in one hand since about 1950, and while you guys with the logic analysers will eventually find the problem IF you know what the signatures are telling you, some old fart like me with a scope probe in one or both hands, will find the problem and have it fixed while you are still consulting the schematic and hooking up your 16 channel logic analyser.

If you do not understand ALL the physics behind how all this stuff works, you are just a wannabe. Out in the real world, we are checking electrolytic caps for ESR first, then cracked "cold" solder joints or corroded IC pins. When you think you are good enough, go sit for a C.E.T. test, pass it with a 99% correct score, and then spend the next 40 years convincing the folks who write the checks that you can indeed walk on water. BTDT, still doing it occasionally at 79.

An O'Scope

[mschiller]

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...]

Adapters. Lots of them.

[some old guy]

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.

hardware

[Gothmolly]

10" table saw
craftsman drill press
Makita battery charger
2 vise, 1 with soft jaws
3 levels
bottle opener

My desktop

[taniwha]

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
cheap chinese stencil jig
(and if I can finally persuade my wife) cheap chinese pick and place ,machine

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.

I suppose I don't do real electronics

[Sangui5]

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.