ESP32-PaxCounter/src/gpsread.cpp
2019-04-14 14:35:07 +02:00

135 lines
3.3 KiB
C++

#if (HAS_GPS)
#include "globals.h"
// Local logging tag
static const char TAG[] = __FILE__;
TinyGPSPlus gps;
gpsStatus_t gps_status;
TaskHandle_t GpsTask;
#ifdef GPS_SERIAL
HardwareSerial GPS_Serial(1); // use UART #1
static TickType_t gps_txDelay = tx_Ticks(NMEA_FRAME_SIZE, GPS_SERIAL);
#else
static TickType_t gps_txDelay = 0;
#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) {
// set time to wait for arrive next recent NMEA time record
static const uint32_t gpsDelay_ms = 1000 - gps_txDelay / portTICK_PERIOD_MS;
time_t t = 0;
uint32_t time_age = gps.time.age();
if ((time_age < gpsDelay_ms) && gps.time.isValid() && gps.date.isValid() &&
gps.time.isUpdated()) {
t = tmConvert(gps.date.year(), gps.date.month(), gps.date.day(),
gps.time.hour(), gps.time.minute(), gps.time.second());
if (time_age < (gpsDelay_ms / 2))
t--;
ESP_LOGD(TAG, "GPS time age: %dms", time_age);
#ifndef GPS_INT
// wait until top of second with millisecond precision
vTaskDelay(pdMS_TO_TICKS(1000 - time_age) - gps_txDelay);
#endif
}
return timeIsValid(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
} // gps_loop()
#endif // HAS_GPS