Test program for I2C several pin assignment
I2C SDA and SCL pin assignments are very flexible on nRF51.
The nRF51822 has a capability to assign PIN every where using PSELSDA and PSELSCL registers.
mbed library can support this flexibility and you can define your own pins!!
I have NOT tested other functions, UART, SPI, PWM and others but I'm sure that we can use same manner in nRF51822 chip.