The flags (defined in /usr/include/termios.h - see ): Ensure it is not in use by another application ') Uart0_filestream = open('/dev/serial0', O_RDWR | O_NOCTTY | O_NDELAY) //Open in non blocking read/write mode O_NOCTTY - When set and path identifies a terminal device, open() shall not cause the terminal device to become the controlling terminal for the process.

immediately with a failure status if the output can't be written immediately. if there is no input immediately available (instead of blocking). When set read requests on the file can return immediately with a failure status

O_NDELAY / O_NONBLOCK (same function) - Enables nonblocking mode. O_RDWR - Open for reading and writing. At bootup, pins 8 and 10 are already set to UART0_TXD, UART0_RXD (ie the alt0 function) respectively #include //Used for UART Setting Up The UART //. (This is based on the example code given here). Turning off the UART functioning as a serial console However that’s no use if you want to use the UART interface for your own application running on the RPi. Using a suitable cable, such as the TTL-232R-3V3-WE, you can connect it to your PC and using some simple terminal software set to 115200-8-N-1 use the command line interface to the Raspberry Pi in the same way as if you we’re using a keyboard and screen connected to it. If you are running Raspbian or similar then the UART will be used as a serial console.

Linux c serial port example