How to identify the contacts of an LCD connector?

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Discussion Overview

The discussion revolves around identifying the contacts of an LCD connector after separating the LCD panel from its driving circuitry. Participants explore the challenges of accessing the dot matrix pixels directly and the complexities involved in driving the panel without its original circuitry.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant seeks guidance on identifying ground contacts and segment driver connections for an LCD panel, emphasizing the need for access to all dot matrix pixels.
  • Another participant suggests that the necessary information is available in the provided datasheet, specifically referencing pages 8 to 14.
  • A different participant notes the complexity of the analog drive scheme required for LCD panels, mentioning that multiple voltage levels must be cycled correctly.
  • There is a suggestion to use a micro-controller with built-in LCD drive capabilities, as well as the possibility of finding a datasheet for bare glass or examining the existing one for conductive traces.
  • A later reply shares that the original poster eventually figured out the pin connections after extensive trial and error, using conductive glue for the contacts.

Areas of Agreement / Disagreement

Participants express differing views on the feasibility of using the LCD panel without its driving circuitry, with some emphasizing the challenges while others provide potential solutions. The discussion remains unresolved regarding the best approach to identify the contacts.

Contextual Notes

Participants mention the reliance on datasheets and the visibility of conductive traces, indicating potential limitations in the information available for identifying contacts.

Who May Find This Useful

This discussion may be useful for individuals working on electronics projects involving LCD panels, particularly those interested in modifying or interfacing with bare LCD screens.

PhysicoRaj
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Hello all,
I needed a bare LCD screen without the driving circuitry for my project. So I opened up the 16x2 LCD module (https://www.sparkfun.com/datasheets/LCD/ADM1602K-NSW-FBS-3.3v.pdf) and separated the panel from the PCB.
Now I have the panel with the ZEBRA connector hanging from it.

Basically I need access to all the dot matrix pixels at a time, which can be used for various purposes in my project.
How do I know which is the ground contact and which contacts come from the segment drivers (row enable? column enable?) and which of them are active low?

Any help appreciated,
Thanks.
 
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PhysicoRaj said:
How do I know which is the ground contact and which contacts come from the segment drivers (row enable? column enable?) and which of them are active low?

all that info is in the datasheet you provided
pages 8 - 14

I would suggest that you are going to have a VERY difficult time using the panel without its drive

what are you trying to achieve ??Dave
 
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LCD panels need a fairly complex analog drive scheme. The output of the driver has multiple voltage levels that need to be cycled in the correct order.

https://www.sparkfun.com/datasheets/LCD/HD44780.pdf

This particular one uses up to 6 different voltages to drive the panel. I would suggest finding a micro-controller with built in LCD drive. Many of the usual manufacturers make them.

As to determining the pinout you will either have to find a datasheet online somewhere for bare glass or examine the one you have. The conductive traces are usually faintly visible.

BoB
 
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It's been quite too late but just thought of ending this saying I worked it out with monstrous efforts for the past two months, trialing out different combos of pins for selecting rows and columns.
Ended up using conductive glue for the 'barely visible' contacts!
Anyway it completed my painful 3rd year project. Thanks for your help.
Cheers.
 
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