mrb_value mrb_mraa_uart_get_dev_path(mrb_state *mrb, mrb_value self) {
mraa_uart_context uart;
const char *path;
uart = (mraa_uart_context)mrb_data_get_ptr(mrb, self, &mrb_mraa_uart_ctx_type);
path = mraa_uart_get_dev_path(uart);
return mrb_str_new_cstr(mrb, path);
}
/* Initialize and open UART communication
* Return uart handle if successful
* baudrate is set to 115200
*/
int uart_init(void) {
mraa_uart_context uart_dev = NULL;
char *uart_dev_path = NULL;
if ((uart_dev = mraa_uart_init(0)) == NULL) {
printf("ERROR : UART\t mraa uart init failed\n");
return -1;
}
if ((uart_dev_path = mraa_uart_get_dev_path(uart_dev)) == NULL) {
printf("ERROR : UART\t mraa uart path does not exist");
return -1;
}
if((uart = open(uart_dev_path, O_RDWR | O_NOCTTY | O_NDELAY)) < 0) {
printf("ERROR : UART\t opening serial device");
return -1;
}
set_interface_attribs(uart, B115200, 0);
set_blocking(uart, 0);
printf("UART successfully initialized on %s\n", uart_dev_path);
tcflush(uart, TCIOFLUSH);
return 0;
}
/**
* Get string with tty device path within Linux
* For example. Could point to "/dev/ttyS0"
*
* @return char pointer of device path
*/
std::string
getDevicePath()
{
std::string ret_val(mraa_uart_get_dev_path(m_uart));
return ret_val;
}
// Serial 1 port setup
void setupSerial1( int baud ) {
/* */
mraa_uart_context uart1 = mraa_uart_init( 0 );
char *devPort = mraa_uart_get_dev_path( uart1 ); // "/dev/ttyMFD1"; // mraa_uart_get_dev_path( uart1 );
printf( " setupSerial1 at start with dev path: %s\n", devPort ); // sets up uart1, connected to Arduino BB pins 0 & 1
serialFDOut = -1; // Say that it is not open...
serialFDIn = -1;
fPtrOut = NULL;
fPtrIn = NULL;
// Try to open File Descriptor
// char devPort[] = "/dev/ttyMFD1";
printf( " Serial port prepare to open %s\n", devPort );
// int serialFDOut = open( devPort, O_RDWR| O_NONBLOCK | O_NDELAY );
int serialFDOut = open( devPort, O_RDWR| O_NONBLOCK | O_NOCTTY | O_SYNC );
// Error check
if ( serialFDOut < 0 ) {
printf( " Error opening %s: %d, %s\n", devPort, errno, strerror( errno ) );
return;
}
printf( " Serial port %s opened successfully\n", devPort );
if ( ( fPtrOut = fdopen( serialFDOut, "r+" ) ) == NULL ) {
printf( " Error opening file associated with %s: %d, %s\n", devPort, errno, strerror( errno ) );
close( serialFDOut );
return;
}
printf( " Serial port access file %s opened successfully\n", devPort );
// For normal files _pfileIn will simply be _pfileOut likewise for file descriptors
fPtrIn = fPtrOut;
serialFDIn = serialFDOut;
setvbuf( fPtrOut, NULL, _IONBF, BUFSIZ );
fflush( fPtrOut );
// Start port config
struct termios tty;
memset(&tty, 0, sizeof tty );
// Error Handling
if ( tcgetattr ( serialFDOut, &tty ) != 0 ) {
printf( " Error from tcgetattr: %d, %s\n", errno, strerror (errno) );
fclose( fPtrOut );
close( serialFDOut );
return;
}
speed_t inSpeed = cfgetispeed( &tty );
speed_t outSpeed = cfgetispeed( &tty );
printf( " Existing port speed, in: %d, out: %d\n", inSpeed, outSpeed );
// Setting other Port Stuff
tty.c_cflag &= ~PARENB; // Make 8n1
tty.c_cflag &= ~CSTOPB;
tty.c_cflag &= ~CSIZE;
tty.c_cflag &= ~CRTSCTS; // no flow control
tty.c_cflag |= CS8 | HUPCL; // 8 bits, enable lower control lines on close - hang up
tty.c_cflag |= CREAD | CLOCAL; // turn on READ & ignore ctrl lines
tty.c_lflag = 0; // no signaling chars, no echo, no canonical processing
// tty.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG); // make raw
tty.c_oflag = 0; // no remapping, no delays
// tty.c_oflag &= ~OPOST; // make raw
tty.c_iflag = 0; // turn off s/w flow ctrl
// tty.c_iflag &= ~(IXON | IXOFF | IXANY); // turn off s/w flow ctrl
tty.c_cc[VMIN] = 0; // read doesn't block
tty.c_cc[VTIME] = 5; // 0.5 seconds read timeout
// Set Baud Rate
if ( 0 != baud ) {
if ( cfsetspeed (&tty, baud ) != 0) {
printf( " Error from cfsetspeed: %d, %s\n", errno, strerror (errno) );
return;
}
}
// Flush Port, then applies attributes
if ( tcflush( serialFDOut, TCIFLUSH ) != 0) {
printf( " Error from tcflush: %d, %s\n", errno, strerror (errno) );
return;
}
if ( tcsetattr ( serialFDOut, TCSAFLUSH, &tty ) != 0) {
printf( " Error from tcsetattr: %d, %s\n", errno, strerror (errno) );
return;
}
// enable input & output transmission
if ( tcflow(serialFDOut, TCOON | TCION) != 0) {
printf( " Error from tcflow: %d, %s\n", errno, strerror (errno) );
return;
}
// purge buffer
{
char buf[1024];
int n;
do {
usleep( 5000 ); // 5ms
n = read( serialFDOut, buf, sizeof( buf ) );
} while ( n > 0 );
}
fcntl( serialFDOut, F_SETFL, 0 ); // disable blocking
/**/
}
