#elif defined(DMX_USE_PORT1) || defined(USART1_RX_vect)
// These definitions are used for using serial port 1
// on ATmega32U4 boards like Arduino Leonardo, Esplora
// You can use it on other boards with USART1 by enabling the DMX_USE_PORT1 port definition
#define UCSRnA UCSR1A
#define TXCn TXC1
#define UCSRnB UCSR1B
#define RXCIEn RXCIE1
#define TXCIEn TXCIE1
#define UDRIEn UDRIE1
#define RXENn RXEN1
#define TXENn TXEN1
#define UCSRnC UCSR1C
#define USBSn USBS1
#define UCSZn0 UCSZ10
#define UPMn0 UPM10
#define UBRRnH UBRR1H
#define UBRRnL UBRR1L
#define UDRn UDR1
#define UDREn UDRE1
#define FEn FE1
#define USARTn_RX_vect USART1_RX_vect
#define USARTn_TX_vect USART1_TX_vect
#define USARTn_UDRE_vect USART1_UDRE_vect
The 1 in the names indicates serial port 1. Change the number to 2 in all the names to use serial port 2.