| General > General Technical Chat |
| LCD driving reverse engineering |
| (1/2) > >> |
| TimB100:
Hello People I'm trying to reverse engineer a LCD panel. The job is to take an off the shelf balance and replace the main PCB so I can add more functions. Like 232 RF USB etc. On the board there is the usual "blob" handling the weight conversion and LCD driver. I want to reuse everything except the main PCB, so I will use a pic, HX711 for the weighing. HT1621B for the LCD driving. The issue I have at this time is trying to work out what the pins are on the LCD. I have scoped the signals and am getting a variety of wave forms. I took pictures of them (below) I think I can identify the commons and the non driven. But have another 2 that seem odd. 1/2 drive 1/3???? So my question is can you tell what they are? And do you have any pointers to how to use the HT1621B to drive the lCD? Many thanks Tim |
| Lukas:
I had to do the same for the pluto watch project: https://github.com/carrotIndustries/pluto#reverse-engineering-bare-glass-lcd-panels I couldn't make sense of the drive waveform as well, so I did what's described above. This however requires making a test jig for the LCD panel. You could also try changing what's on the display and look for waveforms that don't change. |
| TimB100:
Hi Lukas Thanks for the post. Is there potentially an issue if I get the common lines wrong? If I wire it up as per what I think then drive the other lines and I get my pins wrong does it go bang? Cheers Tim |
| TimB100:
Hi Lukas It seems your github post answered my questions. Big thanks! Tim |
| amyk:
You can use a current-limited supply to test LCD connections. The segments are effectively capacitors and will draw far less than 1mA. Brief uses of DC will not cause any damage, but long-term may cause electrolytic degradation. |
| Navigation |
| Message Index |
| Next page |