Gps data is not getting into TTN console after Connecting LoRa E5

[zainmuhammed]

I'm working on building a tracker with Xiao nrf52840 sense, Lora E5 and with NEO M8N GPS module.

Now I have completed connecting XIAO nRF SENSE, LoRa E5 with TTN and it is working properly . Also I connect GPS to Pin number 4 and 5 using SS and it's working properly.
Now both GPS and LoRa individually working properly. When I combine both GPS and LoRa, Lora in hardware serial and gps in software serial LoRa is connecting to the ttn and sending 0, 0 as latitude and longitude. And also I give a separate power for GPS.

anyone can help me to fix the issue

[zainmuhammed]

@zainmuhammed
this is the code

#include <Arduino.h>
#include <U8x8lib.h>
#include <TinyGPS++.h>
#include <SoftwareSerial.h>

static const int RXPin = 1, TXPin = 2;
static const uint32_t GPSBaud = 9600;

// The TinyGPS++ object
TinyGPSPlus gps;

// The serial connection to the GPS device
SoftwareSerial ss(RXPin, TXPin);
U8X8_SSD1306_128X64_NONAME_HW_I2C u8x8(/*reset=*/U8X8_PIN_NONE);
// U8X8_SSD1306_128X64_NONAME_SW_I2C u8x8(/*clock=*/ SCL, /*data=*/ SDA, /*reset=*/ U8X8_PIN_NONE);   // OLEDs without Reset of the Display

static char recv_buf[512];
static bool is_exist = false;
static bool is_join = false;
static int led = 0;

static int at_send_check_response(char *p_ack, int timeout_ms, char *p_cmd, ...) {
  int ch;
  int num = 0;
  int index = 0;
  int startMillis = 0;
  va_list args;
  char cmd_buffer[256];  // Adjust the buffer size as needed
  memset(recv_buf, 0, sizeof(recv_buf));
  va_start(args, p_cmd);
  vsprintf(cmd_buffer, p_cmd, args);  // Format the command string
  Serial1.print(cmd_buffer);
  Serial.print(cmd_buffer);
  va_end(args);
  delay(200);
  startMillis = millis();

  if (p_ack == NULL) {
    return 0;
  }

  do {
    while (Serial1.available() > 0) {
      ch = Serial1.read();
      recv_buf[index++] = ch;
      Serial.print((char)ch);
      delay(2);
    }

    if (strstr(recv_buf, p_ack) != NULL) {
      return 1;
    }

  } while (millis() - startMillis < timeout_ms);
  return 0;
}

static void recv_prase(char *p_msg) {
  if (p_msg == NULL) {
    return;
  }
  char *p_start = NULL;
  int data = 0;
  int rssi = 0;
  int snr = 0;

  p_start = strstr(p_msg, "RX");
  if (p_start && (1 == sscanf(p_start, "RX: \"%d\"\r\n", &data))) {
    Serial.println(data);
    u8x8.setCursor(2, 4);
    u8x8.print("led :");
    led = !!data;
    u8x8.print(led);
    if (led) {
      digitalWrite(LED_BUILTIN, LOW);
    } else {
      digitalWrite(LED_BUILTIN, HIGH);
    }
  }

  p_start = strstr(p_msg, "RSSI");
  if (p_start && (1 == sscanf(p_start, "RSSI %d,", &rssi))) {
    u8x8.setCursor(0, 6);
    u8x8.print("                ");
    u8x8.setCursor(2, 6);
    u8x8.print("rssi:");
    u8x8.print(rssi);
  }
  p_start = strstr(p_msg, "SNR");
  if (p_start && (1 == sscanf(p_start, "SNR %d", &snr))) {
    u8x8.setCursor(0, 7);
    u8x8.print("                ");
    u8x8.setCursor(2, 7);
    u8x8.print("snr :");
    u8x8.print(snr);
  }
}

void setup(void) {
  u8x8.begin();
  u8x8.setFlipMode(1);
  u8x8.setFont(u8x8_font_chroma48medium8_r);
  ss.begin(GPSBaud);
  Serial.begin(GPSBaud);
  pinMode(LED_BUILTIN, OUTPUT);
  digitalWrite(LED_BUILTIN, HIGH);

  Serial1.begin(9600);
  Serial.print("E5 LORAWAN TEST\r\n");
  u8x8.setCursor(0, 0);

  if (at_send_check_response("+AT: OK", 100, "AT\r\n")) {
    is_exist = true;
    at_send_check_response("+ID: DevEui", 1000, "AT+ID=DevEui,\"xxxxx\"\r\n"); // replace 'xxxxxxxxxxxxx' with your DevEui
    at_send_check_response("+ID: AppEui", 1000, "AT+ID=AppEui,\"xxxxxxx\"\r\n"); // replace 'xxxxxxxxxxxxx' with your AppEui
    at_send_check_response("+KEY: APPKEY", 1000, "AT+KEY=APPKEY,\"xxxxxxxxx\"\r\n"); // replace 'xxxxxxxxxxxxx' with your AppKey
    at_send_check_response("+ID: DevAddr", 1000, "AT+ID=DevAddr\r\n"); 
    at_send_check_response("+ID: AppEui", 1000, "AT+ID\r\n");
    at_send_check_response("+MODE: LWOTAA", 1000, "AT+MODE=LWOTAA\r\n");
    at_send_check_response("+DR: IN865", 1000, "AT+DR=IN865\r\n");  // Change FREQ as per your location
    at_send_check_response("+CH: NUM", 1000, "AT+CH=NUM,0-2\r\n");
    at_send_check_response("+CLASS: C", 1000, "AT+CLASS=A\r\n");
    at_send_check_response("+PORT: 8", 1000, "AT+PORT=8\r\n");
    delay(200);
    u8x8.setCursor(5, 0);
    u8x8.print("LoRaWAN");
    is_join = true;
  } else {
    is_exist = false;
    Serial.print("No E5 module found.\r\n");
    u8x8.setCursor(0, 1);
    u8x8.print("unfound E5 !");
  }

  u8x8.setCursor(2, 4);
  u8x8.print("led :");
  u8x8.print(led);
}

void loop(void) {
  if (is_exist) {
    int ret = 0;
    if (is_join) {

      ret = at_send_check_response("+JOIN: Network joined", 12000, "AT+JOIN\r\n");
      if (ret) {
        is_join = false;
      } else {
        at_send_check_response("+ID: AppEui", 1000, "AT+ID\r\n");
        Serial.print("JOIN failed!\r\n\r\n");
        delay(5000);
      }
    } else {
      gps.encode(ss.read());
      float a=gps.location.lat();
      float b=gps.location.lng();
      Serial.println(a);
      Serial.println(b);
      char cmd[128];
      sprintf(cmd, "AT+CMSGHEX=\"%04X%04X\"\r\n", (float)a,(float)b);
      ret = at_send_check_response("Done", 5000, cmd);
      if (ret) {
        recv_prase(recv_buf);
      } else {
        Serial.print("Send failed!\r\n\r\n");
      }
      delay(5000);
    }
  } else {
    delay(1000);
  }
}

[salmanfaris]

Hi @zainmuhammed ,

Can you share the GPS and LoRa output when it’s working?

Also can try capturing the GPS when the device is starting the loop instead after joining the LoRaWAN and see?

Also make sure the device provides have enough to modules. The GPS need more power when you cold start.

[zainmuhammed]

@salmanfaris Today I tried after connecting a 18650 cell,

Data getting in console after integration of both lora and gps.

here you can see that GPS value is 0,0. also in my previous post you can see that GPS value is not reading.
Also the status LED is active after it is connected to the satellite.

[salmanfaris]

@zainmuhammed Can try capturing the GPS when the device is starting the loop instead after joining the LoRaWAN and see?

You can put the GPS value on top of the loop or setup function.

Also, what kind of gateway are you using? Is it configured okay, OTA is done?