16x4 LCD with I2C not displaying text on all rows

Customer:

I’m using a dasduino core, your I2C module, and your 16x4 LCD display. I soldered the I2C to the LCD display and connected everything to the dasduino, but when I upload code, only rows 1 and 3 light up completely white, while the other two show small black squares. I’ve tried many different code examples and adjusting the contrast, but the text won’t display. I’m using address 0x20.

Original message (Croatian)

Dobar dan, kao što piše u naslovu koristim dasduino core, vaš i2c modul i vaš 16x 4 lcd display, ja sam zalemio i2c na lcd display i sve spojio na dasduino no kada unesem kod samo 1. I 3. Red svijetlo skroz bijelo na displayu a druga dva ne svijetle( vide se mali crni kvadratici) . Probao sam puko razlicitih kodova no nikako da se ispise tekst a i mijenjao sam kontrast no ipak nista da li mozda znate u ćemu je problem. Nakon što mi odgovorite mogu vam poslat sliku kako sam sve spojio na vaš mail pa da probate pronaći problem, a ako imate dobar kod mogli biste mi ga poslat da znam odmah ispravit ako mi je u kodu greška. Koristio sam adresu 0x20.

Originally submitted via email support on 4 February 2024. Migrated to the forum for community visibility.

Soldered Support:

Which library are you using? Are you using our library? GitHub - SolderedElectronics/Soldered-16x2-LCD-Arduino-Library · GitHub

You can’t use a generic library for this because our LCD breakout is slightly different from, for example, Adafruit’s. Try using this library specifically and let us know how it goes.

Original message (Croatian)

Vidim da nisi spomenuo library, koristiš li naš library? GitHub - SolderedElectronics/Soldered-16x2-LCD-Arduino-Library · GitHub Ne može se koristiti generički library za ovo jer je naš lcd breakout malo drugačiji od npr. Adafruit-ovog. Probaj baš koristiti ovaj library pa javi kako ide s time.