Customer:
I connected an LCD with I2C. The problem is that nothing displays on the screen. I’m using your I2C module on a classic 16×2 LCD with an easyC cable. I have the Soldered LCD library version 1.0.0 installed. I ran the example, and unfortunately it doesn’t work. Can you help?
Original message (Croatian)
Dobar dan
Spojio sam LCD koji ima I2C.
Problem je što se ništa ne prikazuje na ekranu.
Koristim vaš I2C polemljen na klasičnom 16×2 LCD-u sa easyC kablićem.
Imam instaliran library Soldered LCD verziju 1.0.0
Pokrenio sam primjer, i nažalost ne radi.
Možete li mi pomoći?
Originally submitted via email support on 27 April 2025. Migrated to the forum for community visibility.
Soldered Support:
Have you tried using the potentiometer at the back which adjusts the contrast? Adjusting this potentiometer left or right with a screwdriver while running the example that draws on the LCD could resolve the problem, as you only need to find the optimal contrast center. Just be careful not to go too far in one direction, which could break the potentiometer.
It’s good that you’re using the Soldered LCD library, just to be sure, it’s this one: GitHub - SolderedElectronics/Soldered-LCD-Library · GitHub
If it’s connected properly with the easyC cable to the main microcontroller, then that should be it.
Let me know if the contrast potentiometer helps and we’ll see what’s next.
Original message (Croatian)
hvala na upitu, žao mi je čuti da imate poteškoće s proizvodom, tu smo da pomognemo 
Jesi li probao koristiti potenciometar iza koji podešava kontrast?
Podešavanje ovog potenciometra u lijevo ili desno s odvijačem dok se pokreće primjer koji crta na LCD bi moglo ukloniti problem jer je potrebno samo pronaći optimalno središte kontrasta. Pripazi samo na to da se ne ode previše u jednu stranu što bi moglo pokidati potenciometar.
Dobro je što se koristi Soldered LCD library, samo da budemo sigurni, to je ovaj: GitHub - SolderedElectronics/Soldered-LCD-Library · GitHub
Ako je spojen dobro sa easyC kablićem na glavni mikroupravljač, onda bi to trebalo biti to.
Javi ako potenciometar za kontrast pomogne pa ćemo vidjeti što dalje
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Customer:
Thanks for your help. The library is connected with the easyC cable. It’s not the potentiometer, I’ve been going in circles with it. Tomorrow I’ll test it with a different LCD.
Original message (Croatian)
Dobar dan Roberte, hvala na brizi.
Library Spojen sa easyc kablićem.
Nije do potenciometra, zavrtilo mu se u glavi od mene 
.
Sutra isprobam sa drugim LCD-om.
Javim
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Attachment omitted in migration: Screenshot from 2025-04-28 18-09-32.png
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Soldered Support:
That’s the right library. Which microcontroller are you using as well?
Try downloading the library from GitHub and installing it manually instead of via the Arduino library manager. You need to close Arduino, then delete the old library in Arduino/libraries first.
The library can be downloaded from GitHub and added via “Add a zip library” as shown here: https://docs.arduino.cc/software/ide-v1/tutorials/installing-libraries/#importing-a-zip-library
Let me know if that makes a difference.
Original message (Croatian)
nema na čemu! To je taj library da. Možeš li javiti koji je mikroupravljač isto u pitanju?
Ja sam izvan ureda do sljedećeg tjedna ali biti ću dostupan putem ovih mailova do četvrtka, pa se nadam da ćemo brzo riješiti problem.
Molim probaj library skinuti s githuba i ručno instalirati, ne instalirati preko Arduino library managera.
Potrebno je ugasiti Arduino onda unutar Arduino/libraries prvo obrisati stari library.
Može se library skinut s githuba dodati preko “Add a zip library” kao što je pokazano ovdje: https://docs.arduino.cc/software/ide-v1/tutorials/installing-libraries/#importing-a-zip-library
Javi ako to čini razliku.