[Arduino IDE demo source code for KC868-A6]--#06-OLED_SSD1306_code

[admin]

SSD1306 and (relay) PCF8574 have not use same IIC address, so SSD1306 and relay can work simultaneously. we have already use KC868-A6 with tasmota firmware for ssd1306 and relay ON/OFF. so hardware is OK, now just software problem, sorry, i don't know the u8g2 library details. maybe you not need to use it or change to use another ssd1306 library.