add support for PIN_SDA, PIN_SCL specifying for user's board.

[sonictl]

add support for PIN_SDA, PIN_SCL specifying for user's board.

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[caternuson]

myWire.begin(SDA, SCL); is not a standard Arduino Wire library method: https://www.arduino.cc/reference/en/language/functions/communication/wire/begin/

Are you working with ESP32?

[sonictl]

But how to specify I2C PIN if they're different from the default(4U, 5U) in this example code? I'm using esp8266. pls see line56 of https://github.com/esp8266/Arduino/blob/master/libraries/Wire/Wire.h

[caternuson]

Support needs to be added in the ESP8266 core. This is equivalent to the same issue that arises when using ESP32. See here for how that was dealt with: https://github.com/espressif/arduino-esp32/issues/3779

Try opening an issue with the ESP8266 core.