ESP32-PaxCounter/src/gpsread.cpp
2019-02-23 21:51:24 +01:00

129 lines
3.3 KiB
C++

#ifdef HAS_GPS
#include "globals.h"
// Local logging tag
static const char TAG[] = "main";
TinyGPSPlus gps;
gpsStatus_t gps_status;
TaskHandle_t GpsTask;
#ifdef GPS_SERIAL
HardwareSerial GPS_Serial(1); // use UART #1
#endif
// initialize and configure GPS
int gps_init(void) {
int ret = 1;
if (!gps_config()) {
ESP_LOGE(TAG, "GPS chip initializiation error");
return 0;
}
#if defined GPS_SERIAL
GPS_Serial.begin(GPS_SERIAL);
ESP_LOGI(TAG, "Using serial GPS");
#elif defined GPS_I2C
Wire.begin(GPS_I2C, 400000); // I2C connect to GPS device with 400 KHz
Wire.beginTransmission(GPS_ADDR);
Wire.write(0x00); // dummy write
ret = Wire.endTransmission(); // check if chip is seen on i2c bus
if (ret) {
ESP_LOGE(TAG,
"Quectel L76 GPS chip not found on i2c bus, bus error %d. "
"Stopping GPS-Task.",
ret);
ret = 0;
} else {
ESP_LOGI(TAG, "Quectel L76 GPS chip found");
}
#endif
return ret;
} // gps_init()
// detect gps chipset type and configure it with device specific settings
int gps_config() {
int rslt = 1; // success
#if defined GPS_SERIAL
/* to come */
#elif defined GPS_I2C
/* to come */
#endif
return rslt;
}
// read GPS data and cast to global struct
void gps_read() {
gps_status.latitude = (int32_t)(gps.location.lat() * 1e6);
gps_status.longitude = (int32_t)(gps.location.lng() * 1e6);
gps_status.satellites = (uint8_t)gps.satellites.value();
gps_status.hdop = (uint16_t)gps.hdop.value();
gps_status.altitude = (int16_t)gps.altitude.meters();
// show NMEA data in debug mode, useful for debugging GPS
ESP_LOGD(TAG, "GPS NMEA data: passed %d / failed: %d / with fix: %d",
gps.passedChecksum(), gps.failedChecksum(), gps.sentencesWithFix());
}
// function to fetch current time from gps
time_t get_gpstime(void) {
// !! never call now() or delay in this function, this would break this
// function to be used as SyncProvider for Time.h
time_t t = 0;
if ((gps.time.age() < 950) && (gps.time.isValid())) {
ESP_LOGD(TAG, "GPS time age: %dms, is valid: %s", gps.time.age(),
gps.time.isValid() ? "yes" : "no");
// use recent gps time
t = tmConvert(gps.date.year(), gps.date.month(), gps.date.day(),
gps.time.hour(), gps.time.minute(), gps.time.second());
ESP_LOGD(TAG, "GPS time: %02d.%02d.%04d %02d:%02d:%02d", gps.date.day(),
gps.date.month(), gps.date.year(), gps.time.hour(),
gps.time.minute(), gps.time.second());
}
return t;
} // get_gpstime()
// GPS serial feed FreeRTos Task
void gps_loop(void *pvParameters) {
configASSERT(((uint32_t)pvParameters) == 1); // FreeRTOS check
while (1) {
if (cfg.payloadmask && GPS_DATA) {
#if defined GPS_SERIAL
// feed GPS decoder with serial NMEA data from GPS device
while (GPS_Serial.available()) {
gps.encode(GPS_Serial.read());
}
#elif defined GPS_I2C
Wire.requestFrom(GPS_ADDR, 32); // caution: this is a blocking call
while (Wire.available()) {
gps.encode(Wire.read());
delay(2); // 2ms delay according L76 datasheet
}
#endif
} // if
delay(2); // yield to CPU
} // end of infinite loop
vTaskDelete(GpsTask); // shoud never be reached
} // gps_loop()
#endif // HAS_GPS