How to connect to RaspberryPi by Serial communication

I’m using a Jetson TK1 and want to connect to Raspberry Pi. But I don’t know how to connect to it. I’m going to use GPIO or serial port on Jetson to send data from Jetson to RasPi, by cpp. I could know how to read data by using serial communication on RasPi.

The Jetson TK1’s serial port works just like an x86 machine’s serial port in my testing, but I don’t have much experience with serial ports on the Raspberry Pi. I’d assume the interface would be similar to this.

Thank you, cstotts.
I decide to use GPIO. I’m thinking now that how to write the code…