Hi,You can use 15, 17, or 19 | Microcontroller › Arduino › Arduino MEGA 2560+GPS+TF Card Adapter › Hi,You can use 15, 17, or 19 August 16, 2014 at 4:03 am #12023 AJISH ALFREDParticipant Hi, You can use 15, 17, or 19 pin to connect Tx pin of GPS.