Good Hardware Tools

Wow, I was gonna say I don't know much about scopes but an online acquaintenance recommended a particular Hantek scope a while back (I forget which model).

In general, expect all software coming from hardware companies to be crap. Find something with good independent FOSS support.

On logic analysers, we have a Saleae:

It's not cheap but the software is fairly nice (and runs on Linux). It's also supported by Sigrok, which is an open source logic analyser program for Linux, that supports a wide range of analyser (digital/analogue) hardware.

Sigrok even supports cheap CY7C68013A modules like this one, that you can use as crude logic analysers:

(that gives you 24MHz unbuffered sampling, for as long as your PC can stream out the data in realtime)

For scopes, I often prefer to have the immediacy of having a separate display with knobs to twiddle - having to use a PC app would get in the way, I think. Most of the cost is in the analogue and sampling frontend, so the display doesn't cost very much extra.

Theo

Took a different approach here, never satisfied with second rate test gear, not have the budget for the sort of kit I would want to use and have respect for. Built a up a lab over the years buying s/hand HP, Tek etc and fixing up where needed. Also, multi function gear is always a compromise and often ends up doing nothing very well. If you are a good engineer, you won't be happy with it :-).

Most of the kit here is a decade old or much more and some of it is big and klunky, but once fixed up can be relied upon to work whenever needed. At current prices, could spend 100K on test gear and still not have more capability. Ymmv, of course...

Chris

I needed a new scope a couple years ago and started down this route. But I really didn't find anything PC-attached and great, so ended up buying a used Keysight MSO-X 3054T. This saves screen-shots to USB stick, which is what I most need for engineering documentation, and has decode for SPI, I2C, CAN, LIN, etc. (decoder is an option, make sure you don't buy a used scope without this stuff). I'm REALLY happy with this scope/analyzer. They are available overhauled/used from Keysight. The decoder is great for debugging drivers, but can't log much stuff if you need that for debugging. So...

I just received (Friday) an IKAlogic SP209i (PC-attached) logic analyzer. This can decode just about anything. I haven't had a chance to fire it up and see how it does on some buses here (RS-485 etc). It has programmable scripts so you can add your own decoding and logging. PC software is open source.

Hope that helps! Best Regards, Dave

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Thanks. Partly I want an attached scope so it is very portable. I think I 've given up on shoving anything else in my computer bag, but it would be n ice to have a brief case or second computer bag with all the tools I need f or debugging boards.

The IKAlogic is interesting, but a bit pricey for 9 bits of logic analyzer. One thing I realize it is it's all about the software. If the UI is not so good you won't be happy. As someone has said, they like having knobs to twiddle. I seem to recall reading about someone having a knob bank that w ould work with one of the attached scopes. Too distant a memory to recall any details. It was a nice job, but the knobs were all generic and uniform . Maybe it was a commercial, generic unit, but I think he built it himself . Not sure how it was interfaced to the software unless the software was o pen source.

--

  Rick C. 

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Win 7 and Win 10 but it does have software for Debian and Ubuntu listed.

Best wishes,

--Phil

to acquire some tools. I've needed a new scope for some time, but want an attached scope using the PC for a display. They are no cheaper than the f ull scopes and good ones may be more expensive. The only ones I've found t hat are decent are the Pico Technology scopes. Rather pricey.

sed is good and not too pricey, but I don't recall the name. My only issue with it is that it doesn't have a Linux driver. I keep wanting to switch to Linux, but this is the sort of thing that holds me back. Ah, found it. LogicPort by Intronix. Not a bad device, but no scope.

w/LAPOD meaning it has a 12 bit logic analyzer and not just the scope. Any one use this? Link Instruments

th various math operations like spectrum analysis along with data logging. Again no Linux, but not even Win10!

ogic analyzer. If I can't find anyone who has these devices I think this o ne is less of a risk and likely the right choice anyway. Other than the mu ch more limited buffer size it's probably enough for my needs anyway.

hannel, but adds a pattern generator (on the logic analyzer port) and TDR. I think I'd still want the two channels. A one channel scope is rather li mited.

n't even get the software to run. Zero support... ZERO! I got a full ref und because they couldn't track the package and I still have the piece of j unk. It's just an MCU on a serial port.

nder

Also iOS and Android. Interesting. Only 30 MHz though. $230 seems a bit much for 30 MHz, but it does seem quality. They sell a nice looking digita l cable for $35, but give a crappy Dupont, separate pin connectors cable wi th the unit.

I'll think about this. I really wanted something with a bit faster scope. At least the logic analyzer runs at 100 MHz.

Thanks,

--

  Rick C. 

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I've had good luck in the past buying used HP 20+ year old test equipment on ebay. (It was named HP, then Agilent, now Keysight, which is kinda handy when searching, you get to pick the age of the equipment through the name). The HP16500C supports sending the display over X windows (so you can control it from your desk), and I think it supports NFS mounting so you can get at the trace data. It supports 5 plug in cards. The 16534a is the

2GSa/s 500MHz scope card which gives you two probes, and is about $500 or so. It's excellent. The 16555A cards are logic analyzer cards with 1 million states deep at 125MHz (250MHz if you lose half the channels, and 500MHz fixed sampling clock which is useful to see which signals are transitioning later/earlier than others on a bus). HP Logic Analyzers have very good triggering and selective trace capture ability. Try to get the 16555A already installed as a group in a chassis since there are special connectors to "gang" them together which you'll want. The 16500B chassis doesn't have the X windows or NFS support, so it's a lot less useful.

I picked HP 16500C since I'd used it before--so think of something you used and liked that was new 20 years ago, and buy a used version of that. Everything is 20x-50x cheaper than new, which makes it a great deal.

You're taking some risk on ebay, but it looks like you can get 4x 16555A in a 16500C chassis for under $500. I found one for sale near me 10 years ago and picked it up in person. (This stuff is heavy--I'd be wary of shipping damage). Quality used equipment from 20-25 years ago is better than cheap crap today.

To be safe, I bought two of everything I wanted--one system was perfect, the other had some minor annoyances.

It looks like the PicoScope 6000 new is 5GSa/s at 500MHz with 2 channels for $6916. The 25 year old HP equipment is almost as good (half the sampling rate) for 1/10th the price.

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Thanks for the suggestions. I used one of those HP logic analyzers complet e with a floppy disk drive, MANY years ago. You picked the top end PicoSco pe to compare to. The problem is the HP16500 would barely fit in my car wi thout breaking an axle while the PicoScope will fit in my computer bag!

In the winter I might have to turn off the HP during my electricity peak bi lling time and in the summer I'd have to chill the house in the AM to keep the temperatures down in the afternoon. lol, just kidding of course, but t hey do use a lot of power which gets turned into heat. At this moment, the laptop is the highest power drain that's running. I'd like to keep it tha t way. Heck, I'm considering replacing my fridge because the web says buyi ng a new one will save enough electricity to pay for itself in five years o r less. It's 30 years old too.

--

Rick C. 

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The new fridge will fail in 5 years, planned obsolescence. And the cost to run for your old fridge is a lie to get you to buy a new one.

New fridges are more efficient because they use smaller motors that spin at higher rpm, apparently. Why that makes them more efficient, I have no idea, but that's what the fridge installer guy told me. Anyway, the higher rpm makes them noisier.

I do think the energy savings can be pretty substantial. I have a smallish but full height household fridge and it uses 150W when the motor is running, which is about 1/3 of the time, so 50W average. My mom's fridge is bigger but nowhere near twice as big, and I'm told (haven't measured because my kill-a-watt broke) that it uses 300+ watts when running.

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This fridge actually did exactly that, died just after the warranty ran out . The installed a new compressor at cost... the price of a new refrigerat or. lol. The repaired unit has lasted 30 years so I can't complain too mu ch.

Most likely a replacement would simply result in the old unit going in the basement as a back up unit. If it stays plugged in it will mean the electr icity cost will simply go UP rather than down by getting a new unit. lol

Durn this GG UI... Every time I scroll down a bit to read something, as so on as I start typing it scrolls up to put my typing at the very top of the screen. What is wrong with Google that they would spend time to rewrite th e GG UI, making it worse in the process when no one was complaining about h ow it works? I've noticed any number of changes that simply make the UI le ss usable with no redeeming quality.

--

  Rick C. 

  +- Get 1,000 miles of free Supercharging 
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On 2020-11-17 Rick C wrote in comp.arch.embedded:

I see you complain a lot about GG so why not switch to a decent newsreader? (That would get rid of the afwul GG line lengths as well ;-) )

If it is because you would then need news server access, there are free options. There are also paid services that are really cheap if you only use text newsgroups. The one I am using costs me Euro 1,70 a year because that is the minimum year fee they have. If it were only for the amount data, I could probably do with one tenth of that.

--
Stef    (remove caps, dashes and .invalid from e-mail address to reply by mail) 

As long as we're going to reinvent the wheel again, we might as well try making 
it round this time. 
- Mike Dennison

That's the scam: energy efficient appliances often have critical components that are under specified for the load ... that's *how* they save electricity. The original components are overworked and fail quickly [sometimes even under warranty]. After-market replacements almost always are better ... but since the replacement is correctly sized for the load, once "fixed" the appliance no longer qualifies for its "energy efficient" rating.

George

That's an interesting point. However, regarding fridges and particularly freezers, there's another avenue to energy efficiency: apparently the chest type units are way more efficient than the type with a front door, even if the door stays closed most of the time. They do a better job of keeping heat out, so the motor doesn't have to run nearly as much. I don't know whether more insulation could do the same thing for a front loading design.

I tried freezing a ~4 liter pot of water in my supposedly high efficiency fridge and then unplugging it. The resulting block of ice completely melted in just a day or two. That was disappointing.

You are correct about chest freezers in general being more efficient.

More insulation certainly helps, as does being air-tight. For many years I have liked Sub-Zero[*] refrigerators and freezers.

Sub-Zero freezers vacuum seal when they are closed: on the bigger units the door quite strongly resists being opened, and it pulls strongly for several seconds when closed [you can't just open the door again if you forgot something, you have to wait until the seal is stable].

And they maintain -5..+5 degrees Fahrenheit - not exactly "sub zero" as the name implies, but way below freezing.

The refrigerators don't vacuum seal, but they are heavily insulated and easily keep stuff near freezing.

[*]

If I freeze water overnight in my 14oz travel mug, it will take over 3 hours in the (comfortable) ~70-F car before I can even take a sip. My sister is about an ~8 hour drive: if I keep the mug out of the sun, it will still be partly frozen when I get there.

YMMV, George

I believe it's basically a case of hot air rising, cold air falling - it means the cold air stays in better. And this is particularly true when the door is opened - with a standard fridge, cold air starts falling out rather quickly.

I read somewhere that a Japanese manufacturer had invented a fridge (with standard door and size) used about a quarter of the energy on average, measured in real use in a home over a period of time. The breakthrough was to have a transparent door, so that people don't open the fridge to see what is inside. I thought that was a fine example of thinking outside the box!

Nah, inside the box was just too cold.

The interior volume of the freezer part of a standard fridge might be around 50L, which would make the air mass inside around 60 grams. So even if all the cold air escapes instantly, that's fairly little heat getting in, compared to the heat capacity of the other stuff in the freezer, i.e. around 4 kg of ice in the case of my experiment with the pot full of water. The fridge part might be more like 200L so I'd agree that the heat entering from opening the door several times a day could be substantial.

It still seems to me that better insulation around the freezer would help. When I did the thing with the pot of water, I checked on it maybe

1x-2x day, not so much in the scheme of things. The heat was getting in through the insulation, not from opening the door.