My configuration: -Altera cycloneV socDevKit -Linux kernel : 3.9.0 and debian filesystem from this rocketboards project : http://www.rocketboards.org/foswiki/projects/debian I'm trying to communicate with a serial GPS module (4800 8N1) plugged on the UART mini USB port. But I can't read data from the device. It works fine when I use a PC with a terminal. I even disabled the login prompt in /etc/inittab to directly read data send from the device but nothing happend. Anyone have solution ? Maybe a driver problem or tty settings ? Use HPS USB port could be better ? Thanks.