custom LCD design - Page 1
Forum section: electronics / projects

author: doanerocks
author_rank: Contributor
timestamp: April 15, 2024, 08:54:38 pm
content: My idea is to create s custom display for a NTP/GPS clock where you never set the time, just the time zone. I am sick of clocks I can not trust to have accurate time except my phone and computer which use NTP. You will configure the clock using a web server hosted on the microcontroller on the clock.So I posted this a while ago and I made some modifications to the display based on the suggestions. I also showed the design to a friend that suggested I do character display instead of a starburst or seven segment for the second row. Changing the second row makes it much more flexible to change. The idea for the second row is for showing the day, month, year, or possibly temp/humidity which ever the user prefers. The previous rendition had much skinner seven segments on the top row that people pointed out was out of scale, which I have since fixed. Do people have any companies for getting a custom LCD produced which they can recommend? What do you think of the design? Any other ideas? What do you think of the project?clock-face-01.pdf(97.75 kB - downloaded 225 times.)

author: Kim Christensen
author_rank: Super Contributor
timestamp: April 15, 2024, 09:27:46 pm
content: If this is just a personal project, then I'd simply use a good graphical display and my own fonts.A custom LCD only really makes sense for mass production.

author: Benta
author_rank: Super Contributor
timestamp: April 15, 2024, 09:30:36 pm
content: You're opening a big can of worms here.A simple 7-segment plus annunciators LCD can be made with a single back plane (=cheap).You have to think of it as a single-sided PCB layout, where tracks need to be routed.Moving into dot-matrix will force you to use multiple backplanes (usually 4), which is a different story altogether.Quite frankly, why don't you just use a standard dot-matrix LCD for the whole thing instead?Available off-the-shelf everywhere.

author: PCB.Wiz
author_rank: Super Contributor
timestamp: April 15, 2024, 10:43:31 pm
content: Quote from: doanerocks on April 15, 2024, 08:54:38 pmThere are significant NRE charges for custom LCDs and as you push up the segment count, drivers get more complex and larger.How many do you intend to make ?ePaper displays would be an alternative for clocks. Lower power and wide viewing angle, and you can pick form many sizes these days.

author: doanerocks
author_rank: Contributor
timestamp: April 16, 2024, 01:18:10 am
content: QuoteI really wanted to use a ePaper display but I ruled them out for a few reason. Slow refresh rate, the quickest I could find was 5seconds. I thought there was a max amount of lifetime refreshes.I am taking another look look at epaper, and I found a 10" display that can do 0.3s partial refresh just for the seconds, and a full refresh just under 1 second which should work if it can live up to the specs.I doubt I will be able to see millions but It would be nice to sell hundreds if there are enough fans of accurate time.

author: amyk
author_rank: Super Contributor
timestamp: April 16, 2024, 03:08:58 am
content: Dave has made a video on this topic:https://www.eevblog.com/forum/blog/eevblog-1105-custom-lcd-design-part-3/

author: Kim Christensen
author_rank: Super Contributor
timestamp: April 16, 2024, 03:10:21 am
content: You can already buy WiFi enabled clocks which connect to the internet for sync.In the past, you could buy clocks which sync'd to WWV or similar radio time standard.

author: doanerocks
author_rank: Contributor
timestamp: April 16, 2024, 02:44:09 pm
content: Yes I have watched Dave's custom LCD series many times.

author: doanerocks
author_rank: Contributor
timestamp: April 16, 2024, 03:09:08 pm
content: @Kim Christensen The only wi-fi clocks I have found where LED not LCD. I was hoping for a display that did not need any additional light to read which is why I really like the LCD. Hopefully the new eink display I found will fit my needs, where it can work with out being lit up, and can work with wifi NTP or GPS. But more research will be necessary to determine if the eink can handle all the cycles.Most of the LCD auto time set cocks I found where using WWV. It wold work but I was hoping for one that would work anywhere.

author: doanerocks
author_rank: Contributor
timestamp: April 22, 2024, 08:44:09 pm
content: @PCB.Wiz so I contacted the epaper supplier and it they do not recommend that that the display used for something that is refreshed as often as a clock. AS much as I would love the flexibility of a epaper display it looks like I will need to stick with custom LCD display in order to no have burn in.

author: Kim Christensen
author_rank: Super Contributor
timestamp: April 22, 2024, 10:25:13 pm
content: How many of these clocks are you planning to make?If just one or two, why don't you buy a LCD clock that you like and modify it? You could add a circuit that syncs the existing chip by mimicking button presses at midnight, or just keep the LCD/case while adding your own circuitry.

author: doanerocks
author_rank: Contributor
timestamp: April 23, 2024, 11:40:10 pm
content: @Kim Christensen yes that would definitely make sense for the first couple to just take a off the shelf parts. I was hoping to skip a step but I should probably do a 6 digit seven segment for the top and put a separate 16 or 20 x1 character display on the bottom.

author: PCB.Wiz
author_rank: Super Contributor
timestamp: April 24, 2024, 12:13:45 am
content: Quote from: doanerocks on April 23, 2024, 11:40:10 pmI did find a nice, large 7 segment display (but no modules ?). This has 131 x 30.5 image area.https://www.aliexpress.com/item/1005003087294038.htmlAn alternative would be 3.12" etc OLED displays 256x64 - this has a slightly smaller 79 x 21 active area, but is far more flexible in what can be displayed.https://www.aliexpress.com/item/1005004150204885.htmlor 5.5" 256 x 64 gives more display area, (136 x 34), tho at a higher price of course.https://www.aliexpress.com/item/1005006195056423.html