uSupply Custom LCD

[Aleksolder]

The variety and quantity of replies might be suggestive that the graphic display is the way to go, despite its shortcomings. With graphics, owners could write their own displays. Even though very few might actually do it, knowing it's possible is a strong selling point, and also frees you from this difficult design decision.

I did this with a process control system that I designed, and suddenly a very contentious issue (among fussy customers and my own team) evaporated. Smiles all around.

[xani]

The variety and quantity of replies might be suggestive that the graphic display is the way to go, despite its shortcomings. With graphics, owners could write their own displays. Even though very few might actually do it, knowing it's possible is a strong selling point, and also frees you from this difficult design decision.

I did this with a process control system that I designed, and suddenly a very contentious issue (among fussy customers and my own team) evaporated. Smiles all around.

 I agree but... we do not know what exactly "new" uSupply is and without that it is hard to say if graphical LCD is something that the few % hacking it will put to good use or something that buyers wont even bother touching because base capabilities will be too limited.

Even then, arguably making product more expensive to make it hackable for tiny % is not a good idea.

[mikeselectricstuff]

Fixed segment display, once finalised, reduces the scope for feature creep...

[free_electron]

Fixed segment display, once finalised, reduces the scope for feature creep...

other side of the sword : fixed segment display holds up development until all is cast in stone....

[RES]

Pervasive e-paper?

https://www.digikey.nl/product-detail/en/pervasive-displays/SW074AS182/SW074AS182-ND/4898789
Not cheap.

[xani]

Yes, that sub 1Hz refresh rate, really fucking amazing for power supply display. And that >40mA current when updating, also really fucking awesome for battery powered projects 

[ebclr]

Real LCD's are not the same as paper LCD, and the real ones are much worse

[VEGETA]

what about power consumption?

How much power a TFT screen 2.4" takes compared to suggested LCD?

[ebclr]

For sure a lot more

[boffin]

Guys, it's Dave's project. He can do it however he wants.

[Mr. Scram]

Yes, that sub 1Hz refresh rate, really fucking amazing for power supply display. And that >40mA current when updating, also really fucking awesome for battery powered projects 

It can easily be more than 1 Hz. People even play console emulators on their Nooks. Also, zero consumption when not updating and partial update is available.

I'm not saying it should be e-ink, but let's be factual

[VEGETA]

For sure a lot more

So it is not suitable for battery-based PSU?

[stmdude]

Guys, it's Dave's project. He can do it however he wants.

If anyone thinks he'll do it any other way than the way he wants, they haven't seen many of his videos.

[Mr. Scram]

If anyone thinks he'll do it any other way than the way he wants, they haven't seen many of his videos.

Dave's more than capable of ignoring other's opinions without our help

[KE5FX]

Guys, it's Dave's project. He can do it however he wants.

You submit a project online for comments, you get comments.  That's how it works. 

[ruffy91]

The secret feature:
It's wirelessly powered!

[EEVblog]

Did you change the main power regulating circuit (LT3080/81 + op-amp loops)? or the changes are done in other places?

Yes, the LT3080 had protection and other issues.

[IanB]

Having just waded through this long thread from beginning to end, it seems nobody made the observation that seems important to me:

Regardless of the physical design and layout of the display, the important thing for an open design is that the information to be displayed and the interface to communicate that information is documented. As long as the interface is well defined, the use of a custom manufactured part is no longer a major problem. Anyone with knowledge of the interface can design a replacement for the display using any technology they like.

That's the key thing about systems design: modules and interfaces. Once you define the interfaces, you can redesign and replace any module with a different implementation as long as it preserves the same interfaces.

[VEGETA]

Did you change the main power regulating circuit (LT3080/81 + op-amp loops)? or the changes are done in other places?

Yes, the LT3080 had protection and other issues.

So now LT3081? or you reverted back to using transistor pass element like npn or n-mosfet?

I have used n-mosfet in my design with sepic pre-regulator (1v dropout) and it worked fine after help of others and countless iterations. I remember you saying that you want an off-the-shelf solution and that is why you picked lt3080, I wonder if you changed your mind now.

In any case, I vote for another video series about the subject  at least one video to explain or walkthrough the circuit.

[wilfred]

Having just waded through this long thread from beginning to end, it seems nobody made the observation that seems important to me:

Regardless of the physical design and layout of the display, the important thing for an open design is that the information to be displayed and the interface to communicate that information is documented. As long as the interface is well defined, the use of a custom manufactured part is no longer a major problem. Anyone with knowledge of the interface can design a replacement for the display using any technology they like.

That's the key thing about systems design: modules and interfaces. Once you define the interfaces, you can redesign and replace any module with a different implementation as long as it preserves the same interfaces.

Dave said in post #66

"and right down the bottom:
5) Think about were OSHW comes into it."

This thread is not supposed to be a place for OSHW discussion (post #94) so it might help if it wasn't referred to as an open design since that is a right down the bottom of the list consideration. And possibly an unwelcome distraction.

If you want to start a discussion on OSHW in another thread people might be interested in considering custom components as part of the equation.

[IanB]

Consider an alternative view though. Many people really like the older test equipment from HP and other manufacturers because they have available full schematics and service manuals. This means that people have a chance to repair and maintain the equipment long after it was made.

Now consider that a problem with custom manufactured parts is that if they fail and need to be replaced an original replacement may not be available. However, even if the actual part cannot be obtained, a documented interface spec may at least permit some kind of equivalent to be constructed.

So my comment is not about OSHW any more than classic items of test equipment were OSHW. My comment is about maintenance and repair by future owners.

[EEVblog]

Dave said in post #66
"and right down the bottom:
5) Think about were OSHW comes into it."
This thread is not supposed to be a place for OSHW discussion (post #94) so it might help if it wasn't referred to as an open design since that is a right down the bottom of the list consideration. And possibly an unwelcome distraction.

Why don't you drop it Wilfred?
The design will be open, just because it's not in a way you approve of doesn't mean others should drop it.

[wilfred]

Dave said in post #66
"and right down the bottom:
5) Think about were OSHW comes into it."
This thread is not supposed to be a place for OSHW discussion (post #94) so it might help if it wasn't referred to as an open design since that is a right down the bottom of the list consideration. And possibly an unwelcome distraction.

Why don't you drop it Wilfred?
The design will be open, just because it's not in a way you approve of doesn't mean others should drop it.

Did I say drop it or move it to another thread?  This part of my post that you conveniently left off said:
"If you want to start a discussion on OSHW in another thread people might be interested in considering custom components as part of the equation. "

If anyone does want to discuss the definition of OSHW that I approve of then start up another thread. I haven't made up my own definition. I just use this one here https://www.oshwa.org/definition/
"Open source hardware is hardware whose design is made publicly available so that anyone can study, modify, distribute, make, and sell the design or hardware based on that design."

But I'm not particularly interested in a specific discussion about whether this project is or is not OSHW. It would be hypothetical until the design files are published.

[xani]

Having just waded through this long thread from beginning to end, it seems nobody made the observation that seems important to me:

Regardless of the physical design and layout of the display, the important thing for an open design is that the information to be displayed and the interface to communicate that information is documented. As long as the interface is well defined, the use of a custom manufactured part is no longer a major problem. Anyone with knowledge of the interface can design a replacement for the display using any technology they like.

That's the key thing about systems design: modules and interfaces. Once you define the interfaces, you can redesign and replace any module with a different implementation as long as it preserves the same interfaces.

That's a software engineer perspective. Power supply is not just software.

If device has a form factor with a certain display in  mind you can't "just replace it" unless you find one in same size and connector (or possibly smaller). Especially if you are replacing a custom LCD.

So it does make hacking a much less interesting perspective. Now amount of people who hack will probably be pretty small. Like you might get 5% which will install custom firmware, maybe 0.1% which will actually modify code. But the moment you need to fuck around with replacing display you might as well re-do the hardware.

Yes, that sub 1Hz refresh rate, really fucking amazing for power supply display. And that >40mA current when updating, also really fucking awesome for battery powered projects 

It can easily be more than 1 Hz. People even play console emulators on their Nooks. Also, zero consumption when not updating and partial update is available.

I'm not saying it should be e-ink, but let's be factual

Hey I just read that off datasheet from your own link to a product, 100% facts here. E-ink would just be a novel(and have obvious problems that are not that easy to solve unless you buy ready-made one, like backlight), LCD is just much better fit for the job

[fcb]

Some of the e-ink demos I have seen do a full page refresh each time.  I'm not 100% sure if you can easily do a partial refresh (I stand to be corrected) - so lovely quality to the text but not appropriate for a PSU.

When I looked at them for a project they were very expensive, so I didn't bother looking more deeply into the technology.

+1 for a custom LCD