How to connect 4 pin LCD?

On the UNO board, why SDA and SCL are connected to A4 and A5 and not to SDA/SCL?

What? The SDA/SCL pins depend on the chip you have on your board. As far as I know the UNO uses an ATmega328P, on which the SDA/SCL pins are mapped to pins 4 and 5 of Port C (the actual hardware IO of the microcontroller) which is also shared with the ADC unit (analog pins).

On my board there are A4/A5 and SCL/SDA pins. But I noticed that they are shorted ...

Thank you

I have a multiWii board 4 pin connector marked SDA, SCL, 3.3V and GND. Can I use this connection to hook up a GPS Module 4 pin connector marked VCC, TXD, RXD and GND? I beleive I can run 3.3V to VCC, GND to GND. Right? But, does the SDA go to TXD or RXD? Does the SCL go to TXD or RXD? My bauds rates are set up the same.

  1. GPS are not related to Displays in any way.
  2. No, because TX/RX means UART rather than I2C we are talking about in this thread.