Setting the Serial Port Control Signals with setSerialSignal The following sections demonstrate this through development of the setSerialSignal, getSerialSignal, and querySerial programs.
The file open command returns a file descriptor that is used for serial port configuration, control, reading, and writing. Linux device files provide access to hardware serial ports. The engineers considered writing their own simplified serial communications driver for UART control, but they decided against that after finding C code examples that resemble the required functionality of setSerialSignal, getSerialSignal, and querySerial. Most of these options don't apply for Project Trailblazer. This device driver contains numerous options, beyond basic UART configuration, for control and processing of modem and terminal communications. Manipulating the send and receive buffers requires a more in-depth understanding of the Linux serial device driver capabilities. They discovered that accessing the UART's control signals was straightforward and easy to understand. Michael Sweet's "Serial Programming Guide for POSIX Operating Systems" ( Using Linux-or, more properly, POSIX-serial communications terminology, they searched for code examples that access the serial port's universal asynchronous receiver transmitter (UART) control signals and send and receive buffers. Gary Frerking's "Serial Programming HOWTO" ( The Project Trailblazer engineers found three documents specifically addressing Linux asynchronous serial communications: Linux Serial Communications-Embedded Linux Hardware,Software and Interfacing-ǶÈëʽlinuxÖÐÎÄÕ¾ ǶÈëʽlinuxÖÐÎÄÕ¾ÔÚÏßͼÊé
0 kommentar(er)
