Arduino: RS232 Level Shifter or RS2323 Breakout needed?


I am trying to establish communications between an Arduino Mega2560 (Master) and a customised controller (Slave) via a Master-Slave RS232 link using Modbus RTU. The communication should be bi-directional.

Currently I am simulating the customised controller using ModbusSimulator and connecting to the Arduino using a Sparkfun RS232 level shifter ( It is working.

I am asking if a RS2323 breakout board ( is necessary for communications to the real controller? Or how would I know this? Is the Arduino capable of producing the RS232 signals itself with the level shifter?


Best Answer

RS-232 is simply a high-voltage inverted UART signal along with various other control signals (CTS, RTS, DCD, etc.). If your controller doesn't require these additional control signals then what you have is sufficient. If you need other control signals then you will need the breakout board as well as additional GPIOs on the Arduino in order to generate these signals, plus the code to generate them, plus a DB-9 breakout board to plug into.