The wiringSerial library is intended to provide simplified control вЂ“ suitable for most applications, however if you need advanced control вЂ“ e.g. you may wish to write a larger block of binary data where the serialPutchar() or serialPuts() function may not be the most appropriate function to use, in which case, you can use write() to send the data. system calls on this file descriptor as required. You can use the standard read(), write(), etc. Note: The file descriptor ( fd) returned is a standard Linux file descriptor. This discards all data received, or waiting to be send down the given device. This call will block for up to 10 seconds if no data is available (when it will return -1) Returns the next character available on the serial device. Returns the number of characters available for reading, or -1 for any error condition, in which case errno will be set appropriately. v oid serialPrintf (int fd, char *message, вЂ¦) Д®mulates the system printf function to the serial device.Sends the nul-terminated string to the serial device identified by the given file descriptor. Sends the single byte to the serial device identified by the given file descriptor. void serialPutchar (int fd, unsigned char c).The return value is the file descriptor or -1 for any error, in which case errno will be set as appropriate.Д¬loses the device identified by the file descriptor given. It sets the port into вЂњrawвЂќ mode (character at a time and no translations), and sets the read timeout to 10 seconds. This opens and initialises the serial device and sets the baud rate. int serialOpen (char *device, int baud).Then the following functions are available: To use, you need to make sure your program includes the following file: #include

You just specify the device name in the initial open function. It can use the on-board serial port, or any USB serial device with no special distinctions between them. WiringPi includes a simplified serial port handling library.

Qt serial port rs485