The I2C bus interface requires two lines for data transmission and synchronization (SDA and SCL). If any of these lines is used by another module, the DLN adapter cannot activate the I2C slave port. The
DlnI2cSlaveEnable() function returns only one conflicting pin. If both SCL and SDA lines are in use, you need to call this function three times: two times to detect both conflicting pins and the third time to enable the I2C slave port.
DlnI2cSlaveEnable() function is defined in the