I bought this 2.8" OLED from Aliexpress a few weeks ago: https://www.aliexpress.com/item/32988174566.html?spm=a2g0s.9042322.214.171.124304c4dAWcHG8
And after a ridiculous amount of searching for a datasheet, I came across this one that seems to match the board I bought: https://www.buydisplay.com/download/manual/ER-OLEDM028-1_Series_Datasheet.pdf
Wiring up pins 1 and 2 to ground and 3.3V on a breadboard, I'd expect something to happen with the display, but I get nothing. The display is in 8080 mode, so I wire everything up to a standard UNO board and power everything on. Still nothing. Try changing the power to 5V, no joy.
During my testing, I noticed the back of the display is getting hot. Not sure if that's a good thing or not yet.
So what's the best way to 1) determine if the datasheet I found is correct? 2) check if the OLED is just broken? I don't have a ton of experience with these displays yet, so I'm not sure if just powering the thing on should net some visual response.