"FTDI 3 Pin Cable" description looks incorrect
Please allow me if my understanding is incorrect. To my best knowledge, FTDI cable (TTL-232R-RPi)'s yellow wire is input signal toward PC. It is designed to connect to RPi's TXD pin. And orange wire is output signal from PC. So my understanding is, right connection is as following.
Board Wire Function Pin 1.....Black......Ground Pin 4.....Orange.....PC (TXD) to BBB (RXD) Pin 5.....Yellow.....BBB (TXD) to PC (RXD)
Confirmed on the BBB schematics and DMM, and also experimented by myself.
Regards, Atsushi Yokoyama