- XBee API with multi-serial support This code is based off of the original XBee API library for Arudino. However, that code only supported the main serial UART /Serial/, and I needed it to support the four serial lines on the Arduino Mega 2560. Thus, this fork was created. Normally you would initialize the XBee function as such: void setup() { xbee.begin(9600); } but now, you can set what serial port you want to bind the XBee to, like this void setup() { xbee.setSerial(Serial3); xbee.begin(9600); } Easy peasy!