Dedicated XY scope displays have been around since surplus materials from WW2, at least. A dedicated CRT scope that can have controls that might occasionally need an adjustment is certainly possible. Look in a copy of "The Radio Amateurs Handbook", any 1960's to 1975, or so, edition. 3 inch CRTs were rather common and used a lower voltage DC supply.
BUT it will cost more that that mythical device in post #8.
So the question becomes"just exactly what do your really need??? Knowing the specific requirements will avoid a lot of random guessing.

 

Before you said it was a sawtooth. Now you are saying a triangle wave. Which is it?

Again, what is it about the waveform that is important? What is the user going to do with the information they see displayed on the scope face? What is it they are trying to achieve?

As usual, we are being asked to offer solutions to a problem that isn't spelled out.

What is the goal? What is the underlying problem that needs to be addressed?

If the user is going to turn a knob in order to set the frequency to a desired value, then seeing a waveform on a display is probably less desirable then seeing a numerical display of the waveforms frequency. The same for other parameters.

No, most of the time you will need to page through menus etc. to get to the setup you need.
The only foolproof way I can see is to get an open source scope module and hack the code to have it just power-up in the exact mode you want.

Or... as others have pointed out, if you can detail exactly what the REAL problem you are trying to solve is, I am sure there is a MUCH simpler/better/cheaper way to address it.

You state: "users of this project will most likely be idiots"
Ask yourself this question: when is the last time you saw a product with an oscilloscope screen to be used by idiots?

I see a major contradiction here

Unfortunately, the project requires a very small amount of tuning that can only be dome with a scope

 

This ESP32-based project could do what you want (assuming it is of sufficient bandwidth), it may need some software tweaks but it is open source.

tweeks, that are simple are ok.

 

Unfortunately, the project requires a very small amount of tuning that can only be dome with a scope

Im sorry, I got my waveforms crossed, its a sawtooth waveform, and the parameters if it need to be adjusted to make certain what is coming in is high quality. I guess it could be expressed by a numerical value. but Im not certain

 

Im sorry, I got my waveforms crossed, its a sawtooth waveform, and the parameters if it need to be adjusted to make certain what is coming in is high quality. I guess it could be expressed by a numerical value. but Im not certain

How do you define “high quality”?

 

How do you define “high quality”?

the highest quality I can get, but this is for a basic unit, its not being built for Nasa

 

the highest quality I can get, but this is for a basic unit, its not being built for Nasa

That is not measurable. You have to be more specific.
Let’s put some numbers to it. A sawtooth waveform has to have the following parameters:

1) Starting voltage
2) Ending voltage
3) Period
4) Fall time
5) Non-linearity

 

That is not measurable. You have to be more specific.

I want to see that the amplitude and waveform is accurate

 

I want to see that the amplitude and waveform is accurate

Still not good enough. See my edited post #27.

 

Certainly a dedicated CRT electrostatic deflection scope to display that waveform is fairly simple to design and produce. And if stable components are used it would not require calibration checking more than twice a year, after the initial adjustment. With no processor there will be no menus to deal with. Probably there will need to be a display on/off switch, though. Screen burn is an issue with CRT displays.

 

Unfortunately, the project requires a very small amount of tuning that can only be dome with a scope

They can only be done with a scope, but have to be done by users that are "idiots"????

This brings up a couple of relevant questions.

(1) How reasonable is it to expect the user to be able to recognize an acceptable versus unacceptable scope trace, let alone know how to tune it to move it from unacceptable to acceptable?

(2) If the difference between acceptable and unacceptable is such that it requires a visualization of the waveform, how good does that visualization need to be? What aspect of this waveform is important? How much bandwidth is needed to preserve the necessary details with sufficient fidelity? How well does the measurement leads need to stay compensated over all of the operating conditions? What is the vertical resolution that is needed to adequately see the effect of the tuning?

 

the highest quality I can get, but this is for a basic unit, its not being built for Nasa

That is a useless specification. It doesn't matter what you can get, what matters is what you need.

If you see a sawtooth waveform, what is it that you are going to look at to determine if it is acceptable?

If you can't articulate what constitutes an acceptable waveform, then what possible chance is there for these idiot users to recognize one when they see it?

 

That is a useless specification. It doesn't matter what you can get, what matters is what you need.

If you see a sawtooth waveform, what is it that you are going to look at to determine if it is acceptable?

If you can't articulate what constitutes an acceptable waveform, then what possible chance is there for these idiot users to recognize one when they see it?

The simple way to compare a waveform with another , on a scope, is to print an overlay on a clear plastic sheet and put it on the face of the display. That method is "Simple, Easy, and CHEAP." Besides that, it allows changing the target quite easily.
Am I the only one who has come up with that idea???Somebody should have figured it out before me!!!

 

The simple way to compare a waveform with another , on a scope, is to print an overlay on a clear plastic sheet and put it on the face of the display. That method is "Simple, Easy, and CHEAP." Besides that, it allows changing the target quite easily.
Am I the only one who has come up with that idea???Somebody should have figured it out before me!!!

No, it is an approach that I've seen a few places in various contexts. It still requires that a few things be addressed, though. Most importantly, the notion of how closely the displayed image has to match the reference overlay in order to be considered "good enough" has to be established and then depicted. Then, there is the issue of aligning the displayed waveform with the overlay so that they can be compared, which involves adjustments that change (tune) the waveform and, possibly separate, adjustments that simply shift the waveform to assist the comparison (which can be done either electronically, by shifting the waveform, or physically, by shifting the overlay. This all must be done so that it is doable by these so-called "idiot users" that the TS is concerned with. But none of this lessens the need to decide how good the measurement itself needs to be in order to display a waveform that can be adequately compared to the overlay to decide if the match is good enough.

 

If you want a visual and subjective test of “good enough”, use a dual channel oscilloscope. On one channel, display a “good enough” reference signal in one colour. On the other channel, display the test signal in a different colour. Set the oscilloscope to trigger on the falling edge of both signals for proper synchronization.

Offset the vertical display just slightly to give some separation so that you can observe and compare the two traces.

 

No, it is an approach that I've seen a few places in various contexts. It still requires that a few things be addressed, though. Most importantly, the notion of how closely the displayed image has to match the reference overlay in order to be considered "good enough" has to be established and then depicted. Then, there is the issue of aligning the displayed waveform with the overlay so that they can be compared, which involves adjustments that change (tune) the waveform and, possibly separate, adjustments that simply shift the waveform to assist the comparison (which can be done either electronically, by shifting the waveform, or physically, by shifting the overlay. This all must be done so that it is doable by these so-called "idiot users" that the TS is concerned with. But none of this lessens the need to decide how good the measurement itself needs to be in order to display a waveform that can be adequately compared to the overlay to decide if the match is good enough.

To be honest, even close would be adequate, Im not splitting atoms here

 

Actually, an overlay is a brilliant idea, but it doesn't actually address my problem of having a digital scope, "waking up" with the correct parameters , without manual pushing of buttons

 

Actually, an overlay is a brilliant idea, but it doesn't actually address my problem of having a digital scope, "waking up" with the correct parameters , without manual pushing of buttons

Please understand that I DID NOT SUGGEST A DIGITAL SCOPE!!
Not in any way, shape, or form.
I did suggest a system that included an actual scope tube (a CRT), and a few external controls that would be set and not adjusted again. This is certainly a much older technology, and so probably not commonly offered for sale as a complete package in the online marketplace.

As for being able to align a template properly, that is a very simple process , based on my experience.
Reference marks are left on the scope screen and also on the template, and thus the task is within the capability of most folks.

 

Please understand that I DID NOT SUGGEST A DIGITAL SCOPE!!
Not in any way, shape, or form.
I did suggest a system that included an actual scope tube (a CRT), and a few external controls that would be set and not adjusted again. This is certainly a much older technology, and so probably not commonly offered for sale as a complete package in the online marketplace.

As for being able to align a template properly, that is a very simple process , based on my experience.
Reference marks are left on the scope screen and also on the template, and thus the task is within the capability of most folks.

Unfortunately I have sort-of Pigeon-Holed myself into using a small OLED screen for a scope into this project. again, a high degree of accuracy is absolutely in no way needed, so I think a old scope would be overkill

 

Maybe I missed it but this feels like the first we’re hearing that you already have a display chosen. How are you driving that display?