Adafruit_SSD1306 & WiFiManager on ESP8266 (LOLIN/WEMOS) + OLED_SSD1306 (i²C)

Arduino 1.8.13
LOLIN(WEMOS) D1 R2 &mini
Flash Size “4MB (FS:2MB OTA:~1019KB)”
Debug Port: “Disabled”
Debug Level: “Keine”
IwIP Variant: “v2 Lower Memory”
Exceptions: “Legacy (new can return nullptr)”
Erase Flash:“Only Sketch”

Adafruit GFX Version 1.10.6
Adafruit SSD1306 Version 2.4.3
WiFiManager Version 0.16.0

I am working on a project using a ESP8266 (LOLIN V0.1, cheap Chinese Product) together with a SSD1306 OLED display.
After many separate tests with Wifimanager and different display drivers for the I²C-OLED, I put WiFiManger and Adafruit GFX & SSD1306 together and got an Exception (29) while continuously rebooting!

Exception (29) stats that there is a prohibited memory access. So I tried out many variants commenting out various statements and also changed Flash Size parameter, Board, IwIP: nothing helped…

… except commenting out the “display.cleardisplay();” command when setting up the display.
Now the commands for writing text on the display work, but from the last Test of course there ist still the Adafruit label in the display buffer. :-((
That is a hint for me, that the routine for erasing the RAM of the display buffer of the Adafruit library is faulty!

Did anybody make same experience or has a solution?

thanks in advance, kormorix


My mistake!

“Of course” display.begin… has to be executed BEFORE the other display commands!


with best regards, kormorix