I spent some time trying to use a new display, maybe this post can help someone, i hope so.
I had constrast issues with my display (GMG12864-O6D Ver2.2 from aliexpress), and i spent one day trying to figure it out, chat gpt didnt helped, didn’t found almost anything about this specific display, except one video from Brasil, what i did, i have 13 pins, but i only use 9 of it.
CS, RSE, RS, SCL, SI - are data things and digital ports, you can adapt it, but be careful with esps and stuff, do not use flash digital ports like D3 (GPIO - 0) from NODEMCU V3.
I use VDD, VSS, A, K for power supply, VDD - 3v (it depends of the display that you are using),
VSS - Gnd , A - VIN/5v/3v, K - Gnd, A and K are used for background i guess, you can shunt VDD with A and VSS with K, but I recommend doing this putting them two in the same power lane, not shunting in the display.
Use u8g2 library from olikraus, and if you have a 128x64 display like me, for example, do “CTRL + F” and type “12864” and test almost everything with 5 outputs, my display setting is that:
”U8G2_ST7565_NHD_C12864_F_4W_SW_SPI u8g2(U8G2_R0, /* clock=*/ 5, /* data=*/ 4, /* cs=*/ 2, /* dc=*/ 12, /* reset=*/ 16);”
That display setting inverts my display but works, in the setup type “u8g2.setFlipMode(1);” and it will be just fine.
You can change values, thats default arduino i guess.
I hope i can help someone, maybe thats a lot cofuse, and sorry about my english, not my native language, have a good time, Bye Byee!