Garland animation video in real world with 2 drivers and up to 4 garlands.

Here's a picture of the back of the SSD1306 used in the project. Yes, the interface is I2C as indicated by the jumpers. Have you made sure the display is being selected properly?

Also, your code indicates the I2C interface.  Is that correct? Thank you.

Thanks very much for the quick reply.  There are many of these displays in the market.  Would you be so kind to send me a back image of the one you used.  The photo in the article is not real clear.  It looks like I have the same as yours but a rear photo would clear that up.  Best I can think now is I have a different disply.   Thanks again for the great project and the super fast response.

If you haven't modified the code it should work, assuming things are wired correctly. To verify the code works I reprogrammed my project with Blink, verified that worked, then downloaded the code off the Elektor site and reprogrammed my project with the thermometer code and it does work. So, although your testing seems to point at the code I'm confident the code is fine. I don't have alot of experience with oled displays but they can sure appear to be dead if the back light isn't turned on. Also, have you measured the Reset pin behaviour? Not sure how much this helps, but I'm sure the code is not your problem.