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Xinyuan-LilyGO / LilyGO-T-A76XX

LilyGo A7670X A7608X SIM7670G series
MIT License
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T-A7670G External GPS Quectel L76K #95

Closed randyb128 closed 5 months ago

randyb128 commented 6 months ago

I have a T-A7670G connected to the ceramic antenna you provided. I'm not getting valid GPS data. I modified the GPSShield.ino sketch to output the NMEA sentences. Here's the sketch: /**

ifndef SerialAT

define SerialAT Serial1

endif

ifndef SerialGPS

define SerialGPS Serial2

endif

define BOARD_MODEM_DTR_PIN 25

define BOARD_MODEM_TX_PIN 26

define BOARD_MODEM_RX_PIN 27

define BOARD_MODEM_PWR_PIN 4

define BOARD_ADC_PIN 35

define BOARD_POWER_ON_PIN 12

define BOARD_MODEM_RI_PIN 33

define BOARD_RST_PIN 5

define BOARD_SDCARD_MISO 2

define BOARD_SDCARD_MOSI 15

define BOARD_SDCARD_SCLK 14

define BOARD_SDCARD_CS 13

define BOARD_GPS_TX_PIN 21

define BOARD_GPS_RX_PIN 22

define BOARD_GPS_PPS_PIN 23

define BOARD_GPS_WAKEUP_PIN 19

include

include <TinyGPS++.h>

TinyGPSPlus gps;

void setup() { pinMode(BOARD_POWER_ON_PIN, OUTPUT); digitalWrite(BOARD_POWER_ON_PIN, HIGH);

pinMode(BOARD_RST_PIN, OUTPUT);
digitalWrite(BOARD_RST_PIN, LOW);

pinMode(BOARD_MODEM_PWR_PIN, OUTPUT);
digitalWrite(BOARD_MODEM_PWR_PIN, LOW);
delay(100);
digitalWrite(BOARD_MODEM_PWR_PIN, HIGH);
delay(1000);
digitalWrite(BOARD_MODEM_PWR_PIN, LOW);

Serial.begin(115200);
//Modem Serial port
SerialAT.begin(115200, SERIAL_8N1, BOARD_MODEM_RX_PIN, BOARD_MODEM_TX_PIN);
//GPS Serial port
SerialGPS.begin(9600, SERIAL_8N1, BOARD_GPS_RX_PIN, BOARD_GPS_TX_PIN);

Serial.println("This sketch is only suitable for boards without GPS function inside the modem, such as A7670G");

Serial.println("Works only with externally mounted GPS modules. If the purchased board includes a GPS extension module it will work, otherwise this sketch will have no effect");

Serial.println("If the purchased modem supports GPS functionality, please use examples/TinyGSM_Net_GNSS");

delay(2000);

}

void loop() { while (SerialGPS.available()) { int c = SerialGPS.read(); Serial.write(c); } / if (gps.encode(c)) { displayInfo(); } / delay(1000); }

void displayInfo() { Serial.print(F("Location: ")); if (gps.location.isValid()) { Serial.print(gps.location.lat(), 6); Serial.print(F(",")); Serial.print(gps.location.lng(), 6); } else { Serial.print(F("INVALID")); }

Serial.print(F("  Date/Time: "));
if (gps.date.isValid()) {
    Serial.print(gps.date.month());
    Serial.print(F("/"));
    Serial.print(gps.date.day());
    Serial.print(F("/"));
    Serial.print(gps.date.year());
} else {
    Serial.print(F("INVALID"));
}

Serial.print(F(" "));
if (gps.time.isValid()) {
    if (gps.time.hour() < 10) Serial.print(F("0"));
    Serial.print(gps.time.hour());
    Serial.print(F(":"));
    if (gps.time.minute() < 10) Serial.print(F("0"));
    Serial.print(gps.time.minute());
    Serial.print(F(":"));
    if (gps.time.second() < 10) Serial.print(F("0"));
    Serial.print(gps.time.second());
    Serial.print(F("."));
    if (gps.time.centisecond() < 10) Serial.print(F("0"));
    Serial.print(gps.time.centisecond());
} else {
    Serial.print(F("INVALID"));
}

Serial.println();

}

I have the antenna connected as per the attached photo. download

The NMEA output I'm seeing is this:

$GPGSV,1,1,00,065 $GLGSV,1,1,00,079 $GNRMC,,V,,,,,,,,,,N,V37 $GNVTG,,,,,,,,,N2E $GNZDA,,,,,,56 $GPTXT,01,01,01,ANTENNA OPEN25 $GNGGA,,,,,,0,00,25.5,,,,,,64 $GNGLL,,,,,,V,N7A $GNGSA,A,1,,,,,,,,,,,,,25.5,25.5,25.5,101 $GNGSA,A,1,,,,,,,,,,,,,25.5,25.5,25.5,202 $GPGSV,1,1,00,065 $GLGSV,1,1,00,079 $GNRMC,,V,,,,,,,,,,N,V37 $GNVTG,,,,,,,,,N2E $GNZDA,,,,,,56 $GPTXT,01,01,01,ANTENNA OPEN25 $GNGGA,,,,,,0,00,25.5,,,,,,64 $GNGLL,,,,,,V,N7A $GNGSA,A,1,,,,,,,,,,,,,25.5,25.5,25.5,101 $GNGSA,A,1,,,,,,,,,,,,,25.5,25.5,25.5,202 $GPGSV,1,1,00,065 $GLGSV,1,1,00,079 $GNRMC,,V,,,,,,,,,,N,V37 $GNVTG,,,,,,,,,N2E

I've tried taking the module outside in the open sky for over 30 minutes, same thing. Have also tried 2 different T-A7670 boards and 2 different ceramic antenna's. (the antenna you provide) The $GPTXT "ANTENNA OPEN" is telling me that the active antenna isn't connected. Any ideas?

lewisxhe commented 6 months ago

You probably didn’t read the instructions mentioned in the home page README What you are connecting is not the GPS antenna of L76K. The location you are currently connected to is invalid. The GPS is on the back. https://github.com/Xinyuan-LilyGO/LilyGO-T-A76XX/issues/56

randyb128 commented 6 months ago

I see it now. Thanks for the quick response. You can close this issue