Several months ago we ordered some displays from the Far East and we expected them to work just fine. Unfortunately, they did not. And the problem was not in our library but with the chips. Instead of SSD1306, it seems they put the not that well known SSD1315 OLED display controller. We found that out by looking closely at the PCB, beneath the LCD glass plate.
On another display that we’ve got earlier, a few years ago, and that was using the SSD1306 controller the picture was looking good. SSD1306xLED Testing SSD1306 OLED display controller.
Apparently, the problem was with the display controller. Further experiments proved that. What made it worse for us was that we’ve discovered that from about a hundred display modules we’ve ordered recently half seemed not compatible with our code. We couldn’t even figure out what exactly was the OLED controller on those modules –SSD1306 as stated in the description where we bought them, or the SSD1315 looking at the testing scripts results. So, we decided to just fix the problem for both kinds of chips.