Hi everyone,
I'm having a lot of trouble with some OLED displays on a custom PCB-- they are the SSD1306 128x64 0.96" variety and I need to use them with I2C and 3.3v. I ordered them off Aliexpress
here (perhaps that was my mistake!). They didn't post a data sheet so I decided to copy the
Adafruit OLED Schematic and adapt it...Unfortunately I screwed up a few things in translation.
I attached the original schematic which I had made through JLCPCB. I realized that I forgot to connect /RES and /CS, as they appear to be pulled up in the Adafruit schematic. I tried bodging them together with the DC/I2C_SAO pin next to them which had a 10k pull-up, but I don't know if I'm allowed to join these together or if they need individual pull-ups.
I also forgot pull-ups on the I2C bus so I bodged in some 4.7k resistors. Still no luck.
Then I checked some data sheets like
this one from buydisplay.com and noticed different values for the capacitors, so I changed out for the new caps and still it did not work. I also attached the schematic with changes that reflect my bodges/fixes. It seems like it could be a power issue, because if I read voltage at the charge pump capacitors I get 2.5v on one side and less voltage on the other side which drains away as I meter it..
What's so frustrating is that the rest of my circuit functions as expected, and it runs
these I2C pre-made OLEDs with no issue. I'm pretty lost at this point. Did I get a bad batch of OLEDs? I want to get new PCBs asap but I feel there may still be mistakes in the design
![Sad :(](https://www.eevblog.com/forum/Smileys/default/sad.gif)
Thanks in advance for your help and guidance!!