ESP8266 Community Forum

- Fri Nov 23, 2018 11:47 am #79246 Hello,

I've got a WIFI_Kit_8, which is basically a NodeMCU with an onboard SSD1306 OLED display:
https://github.com/Heltec-Aaron-Lee/WiFi_Kit_series

OLED_SDA = GPIO 4 (Pin16)
OLED_SCL = GPIO 5 (Pin24)
OLED_RST = GPIO 16 (Pin 8)

I'm using the Libraries SSD1306 und GFX from Adafruit to control the OLED.
Now I want to connect to a second I2C device, a DS3231 RTC, sharing the same SDA/SCL pins.
Will this work, or will there be a resource conflict (because two libraries share the same i2c connection)?

- Sat Nov 24, 2018 10:00 am #79254 As long as all I2C devices have their own unique address, they *should* work together.
It actually depends on the implementation of the libraries (they shouldn't all create an I2C instance, but share the same one).

Assumption is the mother of all f*ckups. At least: that's what I'm assuming.