EEVblog #1055 - How to Design a Custom LCD

[EEVblog]

How to design a custom multiplexed LCD display.
Dave takes you through what is required to design your own custom LCD display and what consideration you need for manufacturing and choosing an LCD display driver.

Part 3 in the LCD Tutorial series.

[chriswebb]

Loved this one, Dave! 31 minutes basically flew by watching that.

Also Looks like David did fantastic job on that spec!  Can't wait to see the result after it gets manufactured.  This video was very enlightening for someone with no product experience outside of software.

[Uksa007]

Dave,

Any reason why you didn't opt for a small OLED?

They are only a couple of bucks include the driver (SPI and I2C available), and IMHO are bit more modern looking, better brighter etc.
https://wholesaler.alibaba.com/product-detail/4pin-0-96-white-0-96_60698607420.html?spm=a2700.7782932.1998701000.46.611080d4hPXC0x

Yellow but bigger, I'm sure you could get them in white also
https://www.alibaba.com/product-detail/2-4-inch-yellow-color-oled_60450414866.html?spm=a2700.7724838.2017115.370.39c81fc9mKqBGh

Module only, provide your own driver
https://www.alibaba.com/product-detail/2-42-2-4-inch-128x64_60730189540.html?spm=a2700.7724838.2017115.417.39c81fc9mKqBGh

Looking forward to seeing more info on the uCurrent.

Regards.

[Dubbie]

Uksa, this has been answered in plenty of threads. Some of the reasons are:

# Can be cheaper at volume
# Better visibility
# Lower power use
# Requires very little cycles/resources from the MCU
# Looks more professional
# Dave wanted to do a video series on custom fixed segment LCDs. I’m not aware of any other videos that cover this comprehensively. While there are hundreds covering raster LCDs
# more reasons that I am sure others will contribute.

[Brumby]

Dave,

Any reason why you didn't opt for a small OLED?

If you checked out the situation the uSupply was designed for - you would see why minimising power consumption for everything but the load would be preferable.

[PartialDischarge]

Interesting, and I also learned about the existence of Inkscape!

[amspire]

Interesting, and I also learned about the existence of Inkscape!

The other package to consider is Draftsight. It is a commercial Autocad clone, but it has a free version that is extremely solid. I tried the open source CAD packages, but if you want a very solid Autocad DXF/DWG based package, Draftsight is the best free solution. All the open source alternatives I tried could never handle massive DXF files well. Also Draftsight lets you save as any Autocad file format from Autocad R12 (the DOS based 1992 version) to current.

https://www.draftsight2018.com

There does not seem to be any commercial restriction for using the free license. You just do not get the pro features (not needed).

[mikeselectricstuff]

I don't think there's any advantage to specifying the common groups-you can just use a lookup table to get a sensible segment map .
On a complex display, chances are they won't be able to do the grouping, or may need increased gaps

[coppice]

Its a pity Dave didn't say something about the tradeoffs between different mux options - their effect on voltage requirements, temperature range, viewing angle range, etc.

A number of the Chinese makers still only accept orders for displays up to 4 mux, or charge extra for 6 or 8 mux panels.

[Grapsus]

Very interesting episode. That LCD looks packed with segments ! Very curious to see if they are able to route it and how it looks in the end.

[thm_w]

Dave,

Any reason why you didn't opt for a small OLED?

They are only a couple of bucks include the driver (SPI and I2C available), and IMHO are bit more modern looking, better brighter etc.
https://wholesaler.alibaba.com/product-detail/4pin-0-96-white-0-96_60698607420.html?spm=a2700.7782932.1998701000.46.611080d4hPXC0x

In addition to whats been said, Daves display is 54x50mm or 2.1x2.0", so the first one is far to small (I like the size but I suspect many people would not).
The larger 2.5" OLED you linked is $5 vs 1.47 (USD?), so 3.4 times the price, and isn't as tall.
Third link, can't be sure what the actual price is.

[james_s]

Interesting, and I also learned about the existence of Inkscape!

Inkscape is wonderful, I've been using it for several years, works great for creating snazzy looking front panels for various projects. Print it out, laminate it, spray adhesive to attach it to the panel.


Regarding the LCD that's pretty cool, making a custom segmented LCD is not something that ever even occurred to me. I figured it would only be economical if you were making millions of something.

[floobydust]

Is there an update for the product using this LCD? Where is that PSU...

[MT]

Yes wonder the same, what happened with custom LCD project!?

[zavdimka]

Thanks for great overview of designing custom lcd.
But i still have a one questions
If i want to use rubber strip to connect lcd what recommendations for width and pitch? What about footprint? Should it be always gold pads on pcb?
All design you done in inkscape?