int
carmen_gps_parse_data( char * line, int num_chars )
{
if (num_chars >= 6)
{
if ((strncmp("$GPGGA", line, 6) == 0) || (strncmp("$GNGGA", line, 6) == 0))
{
return(gps_parse_gga(line, num_chars));
}
else if (strncmp("$GPHDT", line, 6) == 0)
{
return(gps_parse_hdt(line, num_chars));
}
else if ((strncmp("$GPRMC", line, 6) == 0) || (strncmp("$GNRMC", line, 6) == 0))
{
return(gps_parse_rmc(line, num_chars));
}
}
return(FALSE);
}
void gps_task(void *pArg)
{
char rx_sentence[200];
char *data_ptr;
uint32_t len;
uint32_t notificationValue;
PRINTF("from gps task...\r\n");
/* Use Task Notification to sychronize between UART Rx handler and GPS task */
xGpsTaskHandle = xTaskGetCurrentTaskHandle();
/* Initialize UART driver with given parameters */
UART_Init(GPS_UART_BASE, &gps_uart_config, GPS_UART_SRCCLK);
/* Initialize UART driver and install our own handler for UART Rx data, which is called by the ISR */
UART_TransferCreateHandle(GPS_UART_BASE, &gps_uart_handle, gps_uart_rx_handler, NULL);
/* Set receive buffer pointer explicitly for custom handling */
gps_uart_handle.rxData = gps_rx_buf;
gps_uart_handle.rxDataSize = 1;
/* Enable RX interrupt (start reception of bytes from GPS module) */
UART_EnableInterrupts(GPS_UART_BASE, kUART_RxDataRegFullInterruptEnable | kUART_RxOverrunInterruptEnable);
/* Turn on RED LED */
while (1) {
/* Wait for notification from UART Rx handler */
if((notificationValue = ulTaskNotifyTake(pdTRUE, portMAX_DELAY)) == 1) {
/* Copy the received sentence */
len = gps_rx_len;
memcpy((void *) rx_sentence, (void *) gps_rx_sentence, len);
/* Parse the received sentence to update gps_info structure */
if (NULL != strstr(rx_sentence, "GPGGA")) {
data_ptr = &rx_sentence[6];
gps_parse_gga(data_ptr, &gps_info);
}
if ((NULL != strstr(rx_sentence, "GPRMC")) || (NULL != strstr(rx_sentence, "GNRMC"))) {
data_ptr = &rx_sentence[6];
gps_parse_rmc(data_ptr, &gps_info);
}
}
/* Check for GPS Fix */
if (NO_FIX != gps_info.fix) {
/* Turn on GREEN LED */
LED_GREEN_ON();
}
else {
/* Turn off GREEN LED */
LED_GREEN_OFF();
}
}
}
void gps_parse(Usart * c_uart)
{
uint8_t c = c_uart->Read();
// DEBUG("%c", c);
switch (gps_parser_state)
{
case(GPS_IDLE):
if (c == '$')
{
gps_parser_buffer_index = 0;
gps_checksum = 0;
gps_parser_state = GPS_DATA;
}
// else
// {
// gps_parser_buffer_index++;
// if (gps_parser_buffer_index > 10)
// {
// gps_set_baudrate();
// gps_change_uart_baudrate();
// gps_parser_buffer_index = 0;
// }
// }
break;
case(GPS_DATA):
if (c == '*')
{
gps_parser_buffer[gps_parser_buffer_index] = c;
gps_parser_buffer_index++;
gps_parser_state = GPS_CRC;
}
else
{
gps_checksum ^= c;
gps_parser_buffer[gps_parser_buffer_index] = c;
gps_parser_buffer_index++;
}
if (gps_parser_buffer_index >= NMEA_MAX_LEN)
{
assert(0);
gps_parser_buffer_index = 0;
gps_parser_state = GPS_IDLE;
}
break;
case(GPS_CRC):
gps_rx_checksum = hex_to_num(c) << 4;
gps_parser_buffer[gps_parser_buffer_index] = c;
gps_parser_buffer_index++;
gps_parser_state = GPS_END;
break;
case(GPS_END):
gps_rx_checksum += hex_to_num(c);
gps_parser_buffer[gps_parser_buffer_index] = c;
gps_parser_buffer[gps_parser_buffer_index + 1] = '\n';
gps_parser_buffer[gps_parser_buffer_index + 2] = '\0';
gps_parser_buffer_index = 0;
gps_parser_state = GPS_IDLE;
// DEBUG(">>%s<<\n", gps_parser_buffer);
if (gps_rx_checksum == gps_checksum)
{
if (cmpn_p(gps_parser_buffer, PSTR("GP"), 2))
{
gps_parser_ptr = gps_parser_buffer + 2;
if (cmpn_p(gps_parser_ptr, PSTR("RMC"), 3))
gps_parse_rmc();
if (cmpn_p(gps_parser_ptr, PSTR("GGA"), 3))
gps_parse_gga();
if (cmpn_p(gps_parser_ptr, PSTR("GSA"), 3))
gps_parse_gsa();
if (cmpn_p(gps_parser_ptr, PSTR("GSV"), 3))
gps_parse_gsv();
}
else if (cmpn_p(gps_parser_buffer, PSTR("PMTK"), 4))
{
gps_parser_ptr = gps_parser_buffer + 4;
if (cmpn_p(gps_parser_ptr, PSTR("011"), 3))
gps_parse_hello();
if (cmpn_p(gps_parser_ptr, PSTR("010"), 3))
gps_parse_sys();
}
}
else
{
DEBUG(">>%s<<\n", gps_parser_buffer);
DEBUG("GPS CHECKSUM IS WRONG! %02X %02X\n", gps_rx_checksum, gps_checksum);
}
break;
}
}