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EEVblog => EEVblog Specific => Topic started by: EEVblog on February 02, 2018, 08:19:26 pm

Title: EEVblog #1055 - How to Design a Custom LCD
Post by: EEVblog on February 02, 2018, 08:19:26 pm
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.


https://www.youtube.com/watch?v=ZYvxgl-9tNM (https://www.youtube.com/watch?v=ZYvxgl-9tNM)
Title: Re: EEVblog #1055 - How to Design a Custom LCD
Post by: chriswebb on February 03, 2018, 02:18:49 am
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.
Title: Re: EEVblog #1055 - How to Design a Custom LCD
Post by: Uksa007 on February 03, 2018, 04:19:43 am
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 (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 (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 (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.
Title: EEVblog #1055 - How to Design a Custom LCD
Post by: Dubbie on February 03, 2018, 06:05:06 am
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.
Title: Re: EEVblog #1055 - How to Design a Custom LCD
Post by: Brumby on February 03, 2018, 06:51:40 am
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.
Title: Re: EEVblog #1055 - How to Design a Custom LCD
Post by: MasterTech on February 03, 2018, 10:48:13 am
Interesting, and I also learned about the existence of Inkscape!
Title: Re: EEVblog #1055 - How to Design a Custom LCD
Post by: amspire on February 03, 2018, 11:21:40 am
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 (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).
Title: Re: EEVblog #1055 - How to Design a Custom LCD
Post by: mikeselectricstuff on February 03, 2018, 12:01:53 pm
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
Title: Re: EEVblog #1055 - How to Design a Custom LCD
Post by: coppice on February 04, 2018, 01:45:11 am
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.
Title: Re: EEVblog #1055 - How to Design a Custom LCD
Post by: Grapsus on February 05, 2018, 09:10:33 pm
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.
Title: Re: EEVblog #1055 - How to Design a Custom LCD
Post by: thm_w on February 05, 2018, 10:16:03 pm
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 (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.
Title: Re: EEVblog #1055 - How to Design a Custom LCD
Post by: james_s on February 06, 2018, 07:24:00 am
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.
Title: Re: EEVblog #1055 - How to Design a Custom LCD
Post by: floobydust on January 08, 2019, 09:10:01 pm
Is there an update for the product using this LCD? Where is that PSU...
Title: Re: EEVblog #1055 - How to Design a Custom LCD
Post by: MT on January 10, 2019, 08:27:09 pm
Yes wonder the same, what happened with custom LCD project!?
Title: Re: EEVblog #1055 - How to Design a Custom LCD
Post by: zavdimka on June 30, 2019, 02:16:01 pm
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?