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Comment by deweywsu | Hacker News Reader

Is this a hit piece by a high-definition display manufacturer? It seems like an unnecessary litany of detractors against one technology without a lot of alternative solutions or trade-offs with others. At the end, there are only 3 sentences that could be called alternatives with the heading "use high resolution displays". Making a "helpful" paper that only lists problems without comparisons or solutions misses all the reasons one would use a 7-segment display (mentioned in the comments here so I won't repeat). There's nothing wrong with this technology. The title "don't use" is too inclusive and is not supported by the paper. I think "Consider not using in certain applications" would have been more appropriate based on the paper's body.

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> Is this a hit piece by a high-definition display manufacturer?

This was the exact thought I had. The paper strikes me as being very odd, and the arguments against using 7-segment LEDs are very thin.

I will agree with one thing, though: the right components to use are an engineering decision and as with all engineering decisions, the right choice (i.e., the right set of tradeoffs) needs to be determined on a project-by-project basis. For a given project, that may mean not using a 7-segment LED. Or it might mean that's exactly the right choice.

Could also be a design decision. No reason to let the engineers make all the choices.

Considering the paper does not specify that it has no conflicts of interest in the usual place where it would, we should assume the author is involved with such manufacturers

Huh?

As someone designing electrical circuits that might or might not use a 7-digit display this seems rather to be a guide for which use cases to avoid them.

Electrical engineers sadly sometimes don't think about that at all and slap what they know onto everything. When you have a medical device where a reading error or ambiguity can have serious consequences you might want to be aware of that. There are 7-segment-display usecases where that is not an issue irrelevant, e.g. because you have enough contextual clues to not hold the device wrong and read it upside down or because the potential damage from a reading error is irrelevant.

But this is still a design consideration one should be aware of. Especially in times where 7-segment displays aren't necessarily the cheapest option.

Most other display technologies have their downsides too. For example, fot-matrix LCDs are far more fragile and more easily damaged by sunlight or heat than 7-segment LEDs. If you don't discuss that, but dwell on the downsides of 7-segment displays, it does feel a bit like a hit piece.

In fact, 7-segment displays aren't even a monolithic technology, and not all of the gripes in the article apply to every implementation. You have traditional LED models, LCD 7-segment displays, and then some OLED flavors, VFDs, and even electromechanical designs in niche applications.

Almost any 7 segmented display could be replaced by an analogue gauge. For time, for temperature, for selecting options. When a device has a segmented display, I assume it is to cut costs.

When a device has many analog gauges, I assume it is an unnecessarily expensive device.

Few modern use cases actually benefit from the qualities of an analog gauge. It seems to be more of a status marker, at least for consumer goods. Military and ruggedized applications are a different story.

What would be an application where a segmented display is just as good or better than an analogue gauge? The only one I can think of is a bedside clock or other device that will be used in the dark and can benefit from self-illuminance.

Especially household appliances are worsened by the switch from analogue to digital. A microwave oven used to be so practical to operate. Just dial the clock to your desired time and that's it. Now, you have to press +30s button a bunch of times, or type your time. They're even trying to put digital on stoves, clearly not intended for use by people who actually cook. Induction stoves all have this problem. My air fryer is much worse to operate than it should, because they insisted on digital. It would be perfectly fine with a gauge for time and one for temperature. Now there's all these buttons and a segmented display.

I have a segmented display thermometer. It's not better than an analogue in any way I know of, but they're cheaper. I have a segmented display speedometer on my motorcycle. It is of course getting its input from an analogue measurer, so why transfer it to digital?

Modern speedometers are digital. A magnet or metal disk with cutouts rotating with the transmission produces pulses in a magnetic field sensor, the pulses are counted by a microchip. The data is sent to the dashboard over a packet-based computer network.

I for one find a "71" in large digits much easier to read than trying to figure out where between the lines a little needle is pointing. If the opposite were really true, we'd draw little pictures of gauges to communicate numbers.

In cars I see more analog than segmented displays for the speedometer, but I'm sure you're right that the underlying technology can be digital. For MCs, I kind of agree with you that numbers are nicer.

My current car and one previous had digital speed displays. It's starting to happen, but the inertia is high.

As the owner of some analog gauges that have lost their calibration, I disagree.

But a segmented display will also get its input from an analog source, right? Or are there some applications that I'm overlooking?

The current day digital sensors are a lot more reliable. I have multiple cheap digital thermometer etc gadgets and they read the same temperature to within 0.1 C, humidity to ~0.5%, and so on.

The source is analog only in the sense that physics is "analog" until you get to Planck scale or to quantum phenomena.

I also have some digital thermometers, and personally don't have any preference digital vs analog in them. For home use, +/- one degree or percentage of humidity don't really make a difference. As for reliability I don't think you can beat analog, which will last for decades without changing a battery.

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