TTL-to-RS232 module convert a 2×5-pin TTL input header to a DB9-M RS232 output port. The pinout of the input pins makes it plug-in compatible with the SBC-SAM9G45 development board's COM0-COM3 expansion headers (or the Bus-Serial expansion module's J3-J6 headers). A ribbon cable is provided to make that connection. However, the standard 2.54mm pitch of the header pins makes it easy to wire up to practically any development system with TTL UART headers

MAX3232ESE+ RS232 transceiver

Converting TTL level logic to RS232 levels
Support 5-wire(RX, TX,RTS,CTS) serial port
Data rates up to 120kbps
Board Support: SBC-SAM9G45 | NET-SAM9X25.

Input interface

TTL level input, 2×5-pin 2.54mm (0.1") pitch header. The pinout is printed on the PCB for easy reference.

Pin	Signal Name	Pin	Signal Name
1	NC	2	RXD
3	TXD	4	NC
5	GND	6	NC
7	RTS	8	CTS
9	NC	10	VDD33(3.3V)

Output interface

RS232 level, DB9 Male connector. The table below mimicks the orientation of the connector on its side.

Pin	Signal Name	Pin	Signal Name
1	NC	2	RXD1R
3	TXD1R	4	NC
5	GND	6	NC
7	RTS1R	8	CTS1R
9	NC