Hy, I worked on a source half a year ago with an older Energia (I do not know exactly which one.). I was able to acces UartIntHandler and UartIntHandler2() functions directly. As I remember I do not change the content of Energia under OSX. Now I try to modify 1-2 things for example in the startup_gcc.c or hardwareserial.c, but the are not working. Can you help me how could I reach the UART interrupt handlers from Energia? (The setup of UART module worked on CCS or IAR before.) Can I use something like attachinterrupt()?