GPIO Socket (J15)
The GPIO socket, marked J15 on the circuit board, allows access to several different power and data lines:
- I2C serial protocol
- Spare pins on the FPGA
- 5v, 3.3v and GND
The GPIO is not populated and requires a socket to be installed (2 x 10 IDC 2.54mm spc. Male Pin Header). Pull up/down resistors may be required for some pins to limit current.
In June 2019 it was announced that pins 4 and 17 of J15 would be used for two additional keyboard connections on full cased Nexts. Final specs have not yet been finalised.