Serial communication NUCLEO STM32F103
check this document http://www2.st.com/content/ccc/resource/technical/document/user_manual/98/2e/fa/4b/e0/82/43/b7/DM00105823.pdf/files/DM00105823.pdf/jcr:content/translations/en.DM00105823.pdf
page 24, check your SB62 and SB62, configure your uart in mcu and you can send data from mcu to PC via usb virtual com port