Can anyone identify this LCD module for me? - Page 1
Forum section: electronics / projects

author: shawty
author_rank: Regular Contributor
timestamp: January 27, 2025, 04:49:22 pm
content: Thanks in advance...Got a random box of "Electronics Bits" given to me, and amongst them is a handful of these small LCD Screens.I've never seen them before, and general googling against anything printed on the PCB and/or a description of the layout has yielded no help (Not that Google, Bing and co are much help these days :-) )Even if I can't ID them. Just working out the pinout to see if I can get it to display something would be a bonus, see if I can in any way make use of them.CheersShawty

author: Haenk
author_rank: Super Contributor
timestamp: January 27, 2025, 05:35:48 pm
content: If you have many of them, maybe sacrifice one and detach the display from the module. Is is likely connected by two zebra strips, which are reusable (so everything might be fine again when reassembling).Usually a model and manufacturer is printed on the back of the LCD, that might help to identify the module or driver.

author: coromonadalix
author_rank: Super Contributor
timestamp: January 27, 2025, 08:28:15 pm
content: mm i would say there is a blob the other side, could be some 2x8 or even an 1x8 ?? for the grounds, normally the metal frame must touch a ground pad, for the other you could try an 5vdcsome lcd with no contrast pot will remain white as nothing will appear, but upon power you should see some small darkness, and sometimes fiddling with an humid finger you could provoke brightness / darker charactersbut for sure one need to put under some stress if i may say, unless this one is kinda serial based or spi based orif you play with a flash light on it sometimes you can see the digits in the lcd glass it could even be a clock lcd with say 4 digits and points between 2 digit group ... for the low pins count, could even be an muxed lcd ....

author: mariush
author_rank: Super Contributor
timestamp: January 27, 2025, 08:56:22 pm
content: I'd start by assuming it's a hd44780 clone / compatible display, maybe forced in 4 bit mode.So try the default arrangement but with just the 4 data bits that are required, and maybe leave out the option r/w pin (if you're only writing to the lcd then that pin can be omitted)see page 4 in this datasheet:https://newhavendisplay.com/content/specs/NHD-0216K1Z-FL-YBW.pdfVdd, Vss , Vo (contrast), R/W (optional), E, D1, D2, D3, D4

author: shawty
author_rank: Regular Contributor
timestamp: January 27, 2025, 10:57:17 pm
content: Quote from: Haenk on January 27, 2025, 05:35:48 pmYes I was thinking about that, but despite having a handful of them (I have about 10), I'd like to try to not break anything just yet :-)Myself and zebra strips don't have the best of relationships, as the display on my musical keyboard will testify :-DI may, very well end up doing this however.

author: shawty
author_rank: Regular Contributor
timestamp: January 27, 2025, 11:00:48 pm
content: Quote from: coromonadalix on January 27, 2025, 08:28:15 pmIf you look closely at the 3rd image there appears to be a "clock" display on it ... IE: "88:88" followed by a couple of small Icon's I can't make out, might be 'am' & 'pm' symbols.It's definitely not a pixel display, I know that much, I'm throwing the idea around that maybe those 8 connectors along the bottom are 7 seg + a ground.The 5 pad's down one side do also seem to be electrically connected, but the 3 on the opposite side do not.

author: shawty
author_rank: Regular Contributor
timestamp: January 27, 2025, 11:03:10 pm
content: Quote from: mariush on January 27, 2025, 08:56:22 pmYou know, that never crossed my mind to be fair!!! - well not fully anyway. I did look at it and think, "8 pins... yea not enough there..." but now you mention forced 4 bit mode.That said as I mention in my previous reply, there does look to be a 7 seg type display in the crystal as opposed to a pixel display.

author: inse
author_rank: Super Contributor
timestamp: January 27, 2025, 11:10:27 pm
content: Rub the glass with a dry cloth, preferably synthetic and the segments will appear.Then you can decide whether its worth deeper investigation (which I pretty much doubt).

author: shawty
author_rank: Regular Contributor
timestamp: January 30, 2025, 09:44:46 pm
content: Neat trick!!Alas doesn't show anything on this thing, glass on front however is very stiff, I think there's a chunk of quite solid perspex in front.I think I'm gonna go for broke and start probing with a 5v + gnd on the pins see if anything happens

author: PCB.Wiz
author_rank: Super Contributor
timestamp: January 31, 2025, 12:16:58 am
content: Quote from: shawty on January 27, 2025, 04:49:22 pmThere are not many connections upwards to the LCD, I count about 30 so that might be direct segment drive of 88:88 and some icons.A meter in diode mode should find any CMOS pins, and check if any pins share with the caps to find your supply pins.I'd start lower than 5V initially and with some series resistance as LCDs are very low power.4 caps is a little unexpected, maybe there is a charge pump, which might suggest a lower supply link.

author: Smile2016
author_rank: Regular Contributor
timestamp: January 31, 2025, 01:27:53 am
content: Quote from: PCB.Wiz on January 31, 2025, 12:16:58 amI agree with you on this—it's likely a 7-segment display from pictures with 3.5 or 4 digits, including a decimal point, colon, and some symbols [I also counted 32..33 pins on ribbon side]. It seems more like a panel meter rather than a clock, as a clock would typically have a crystal. The capacitors could be for backplane voltages, negative voltage, or a virtual ground if it's a voltmeter. Using a 3V supply and a 100–200Ω limiting resistor could help identify the power pins.

author: coromonadalix
author_rank: Super Contributor
timestamp: January 31, 2025, 03:31:12 am
content: if its a clock display it does not need to have crystal etc ... it's a display, the main electronics are not therewe do see some digits on the pictures and they are indeed grouped by 2 digits and separated by 2 points : ....for theses 4 capacitors i would try with an ohm meter if one pin of each is common to another one or more, i would say it could be a ground, and check that common pin if it goes to one of the 8 pins header, if it is for the others i would try a 3.3v or a 5v ...for sure one of theses must be between the vcc and ground supplycheck if one of them has both pins going to the 8 pin header

author: Smile2016
author_rank: Regular Contributor
timestamp: January 31, 2025, 04:18:06 pm
content: Quote from: coromonadalix on January 31, 2025, 03:31:12 amIt's probably "just a display" 7 segment , 4 digits... with a shift register attached to it? Take a look at this link:https://www.microchip.com/en-us/product/ay0438Microchip AY0438... for all 32 pins on the ribbon, which is similar to the HC0438A or others...the blob. If this makes sense , you'll need to clock in the data you want. I would still try to identify the power and see if those segments look nice for further investigation. The static check has always worked for me. With the metal frame removed, hold the LCD from the sides and touch the ribbon with another potential; all segments should light up. Just walking around and touching a metal surface in the kitchen worked for me. as for pin-count [just speculating here] DATA-IN, DATA-OUT, CLOCK, VCC, GND, LOAD, stiii 2 extra : BACKLIGHT A, BACKLIGHT K ??

author: ahsrabrifat
author_rank: Regular Contributor
timestamp: February 01, 2025, 03:16:32 pm
content: At first I thought it was a generic 8x2 LCD. But the number of pins does not say so. Maybe it is a custom-made display for a specific product.

author: shawty
author_rank: Regular Contributor
timestamp: February 03, 2025, 12:37:46 pm
content: Quote from: Smile2016 on January 31, 2025, 01:27:53 amNot being a clock would be a definite possibility, the box of parts came from an old Ham Radio collector, so there's potential that they could be some kind of frequency display or similar.All possible points of exploration for me thus far however. Just had some other work to do, so not had chance to did back into this just yet.

author: shawty
author_rank: Regular Contributor
timestamp: February 03, 2025, 12:42:33 pm
content: Thanks all so far, plenty for me to get on with testing :-)CheersShawty

author: inse
author_rank: Super Contributor
timestamp: February 03, 2025, 12:44:52 pm
content: Quote from: shawty on February 03, 2025, 12:37:46 pm..and if they were for a radio controlled clock project?😉

author: shawty
author_rank: Regular Contributor
timestamp: February 11, 2025, 08:34:56 pm
content: Quote from: inse on February 03, 2025, 12:44:52 pmTouche! :-)