ESP32-PaxCounter/src/gpsread.cpp

#ifdef HAS_GPS

#include "globals.h"

// Local logging tag
static const char TAG[] = "main";

// read GPS data and cast to global struct
void gps_read() {
    gps_status.latitude     =   (uint32_t) (gps.location.lat() * 1000000);
    gps_status.longitude    =   (uint32_t) (gps.location.lng() * 1000000);
    gps_status.satellites   =   (uint8_t) gps.satellites.value();
    gps_status.hdop         =   (uint16_t) gps.hdop.value();
    gps_status.altitude     =   (uint16_t) gps.altitude.meters(); 
}

// GPS serial feed FreeRTos Task
void gps_loop(void * pvParameters) {

    configASSERT( ( ( uint32_t ) pvParameters ) == 1 ); // FreeRTOS check

    // initialize and, if needed, configure, GPS
    #if defined GPS_SERIAL
        HardwareSerial GPS_Serial(1);  
    #elif defined GPS_I2C
        // to be done
    #endif

    while(1) {

        if (cfg.gpsmode)
        {
            #if defined GPS_SERIAL
                
                // serial connect to GPS device
                GPS_Serial.begin(GPS_SERIAL);
                
                while(cfg.gpsmode) {
                    // feed GPS decoder with serial NMEA data from GPS device
                    while (GPS_Serial.available()) {
                        gps.encode(GPS_Serial.read());
                    }
                    vTaskDelay(1/portTICK_PERIOD_MS); // reset watchdog
                }    
                // after GPS function was disabled, close connect to GPS device
                GPS_Serial.end();

            #elif defined GPS_I2C
                
                // I2C connect to GPS device with 100 kHz
                Wire.begin(GPS_I2C_PINS, 100000);
                Wire.beginTransmission(GPS_I2C_ADDRESS_WRITE);
                Wire.write(0x00); 

                i2c_ret == Wire.beginTransmission(GPS_I2C_ADDRESS_READ);
                if (i2c_ret == 0) { // check if device seen on i2c bus
                    while(cfg.gpsmode) {
                                // feed GPS decoder with serial NMEA data from GPS device
                                while (Wire.available()) {
                                    Wire.requestFrom(GPS_I2C_ADDRESS_READ, 255);
                                    gps.encode(Wire.read());
                                    vTaskDelay(1/portTICK_PERIOD_MS); // reset watchdog
                                }
                            }    
                    // after GPS function was disabled, close connect to GPS device

                    Wire.endTransmission();
                    Wire.setClock(400000); // Set back to 400KHz to speed up OLED
                }

            #endif
        }
       
        vTaskDelay(1/portTICK_PERIOD_MS); // reset watchdog

    } // end of infinite loop

} // gps_loop()
    
#endif // HAS_GPS