Hi,
Just for anyone interested, I bought an FTDI Chip TTL-232RG-VREG1V8-WE (1.8 volt) USB to TTL serial cable and soldered the wire leads the the Hikey J16 as so:
ftdi orange (TX) - Hikey pin2 (RX) ftdi yellow (RX) - Hikey pin4 (TX) ftdi black (GND) - Hikey pin3 (GND) ftdi red (VCC) - open ftdi green (RTS) - open ftdi brown (CTS) - open
Seems to be working fine.
[1] http://www.ftdichip.com/Support/Documents/DataSheets/Cables/DS_TTL-232RG_CAB...
-Geoff