Hello, --I observe that port pin p29 does not work, although it is configured correctly as DigitalOut. However, other pins work as they should. --When I do a short test program, which switches all pins, everything works - my mbed seems not to be defective... --Is it possible that use of two I2C interfaces (p27,p28 as I2C slave) prevents the simultaneous use of p29? --p30 is working properly, for example ... --I've already checked several times to confirm whether all pins are initialized, but the compiler gives no error message - so I hope that someone here has an explanation? (the error occurs on naked mbed too, only with plugged USB cable - so I don't think something is wrong with the rest of my circuit...)-- Ok - I couldn't fall asleep unless a last try to fix it; it was the simpe fact of using the name of a variable twice... Although having searched for all occurences in my code i forgot to look in the header file... Now it works - good night!! :-) Michael