I have a need for an additional serial port. There are a few topics that show an alternative pin out where the PWM output of the mbed on P25/26 can be switched to serial. This is a move from P13/14. There is an example below. My question is... Where does one make the change to pin assignment? I assume this is in mbed.h. I can not edit mbed.h in the compiler. Is there documentation on how to reset pin assignments> Thanks http://mbed.org/handbook/Serial At the top of this page it shows a small diagram depicting which pins you can use the Serial object with and lists them thus:- Quote: The Serial Interface can be used on mbed pins p9/p10, p13/p14, p28/p27 and USBTX/USBRX However, it's possible to "move" a set of pins from the p13/p14 slot to p26/25 pins (if you are not using p26/p25 for some other function). This is useful if you need to use all three UARTs and both SPI ports in a project. Below is the standard "Mbed pinning diagram" and an alternative pinning diagram I hashed up from the original depicting this alternate method. /media/uploads/AjK/pinout-standard.png /media/uploads/AjK/pinout-alternate.png