I am trying to implement GPS code in the nrf9160 but I cant find the function nrf_modem_gnss_init(); to initialize GNSS inside the modem in , is it being initialised within nrf_modem_gnss_start() function internally ? please help on this.
I am trying to implement GPS code in the nrf9160 but I cant find the function nrf_modem_gnss_init(); to initialize GNSS inside the modem in , is it being initialised within nrf_modem_gnss_start() function internally ? please help on this.
This is an internal GPS setup and has external on-board antenna attached to it.
I can see voltages around D1(2.489 at cathode ) , D2 (2.673 at cathode ) which further goes to c1(2.48), c2(2.49) and c3(2.67), c4(2.67) which are sufficient to power up LNA.
Is there anything else I am missing in the code ?
Also coex is used for coexistence of LTE along with GNSS. Here I am using GNSS mode only in the code.
Hi Team,
We have tried as per your suggestion that configured COEX0 pin as below but still unable to get longitude and latitude. Can you please provide your inputs to fix this issue. We have provided our schematics and code below.
Firmware files:
#include <zephyr/kernel.h>
#include <zephyr/logging/log.h>
#include <zephyr/drivers/gpio.h>
#include <nrf_modem_gnss.h>
#include <modem/nrf_modem_lib.h>
#include <nrf_modem_at.h>
#include "AT_CMD/at_cmd.h"
#include <modem/lte_lc.h>
#include "modem/modem.h"
#include "gps.h"
#if IS_ENABLED(CONFIG_LTE_LINK_CONTROL)
#endif
/* Get gps_en node from devicetree */
#define GPS_EN_NODE DT_NODELABEL(gps_enable)
/* GPIO specification for GPS enable */
static const struct gpio_dt_spec gps_en = GPIO_DT_SPEC_GET(GPS_EN_NODE, gpios);
LOG_MODULE_REGISTER(gnss_app, LOG_LEVEL_INF);
static struct nrf_modem_gnss_pvt_data_frame pvt_data;
#define ENABLE_GNSS_RF_ROUTING 0
static int sv_in_view(const struct nrf_modem_gnss_pvt_data_frame *p)
{
int count = 0;
for (int i = 0; i < NRF_MODEM_GNSS_MAX_SATELLITES; i++)
{
if (p->sv[i].sv > 0)
{
count++;
}
}
return count;
}
static int sv_used_in_fix(const struct nrf_modem_gnss_pvt_data_frame *p)
{
int count = 0;
for (int i = 0; i < NRF_MODEM_GNSS_MAX_SATELLITES; i++)
{
if (p->sv[i].flags & NRF_MODEM_GNSS_SV_FLAG_USED_IN_FIX)
{
count++;
}
}
return count;
}
static void gnss_event_handler(int event)
{
int err;
static bool first_log = true;
switch (event)
{
case NRF_MODEM_GNSS_EVT_PVT:
err = nrf_modem_gnss_read(&pvt_data, sizeof(pvt_data), NRF_MODEM_GNSS_DATA_PVT);
if (err)
{
LOG_ERR("Failed to read PVT data, err=%d", err);
return;
}
if (first_log)
{
first_log = false;
LOG_INF("GNSS PVT struct size=%u", (unsigned)sizeof(pvt_data));
}
LOG_INF("PVT flags=0x%08x", pvt_data.flags);
for(int i = 0; i < NRF_MODEM_GNSS_MAX_SATELLITES; i++)
{
if(pvt_data.sv[i].sv >0)
{
int used_in_fix = (pvt_data.sv[i].flags & NRF_MODEM_GNSS_SV_FLAG_USED_IN_FIX) ? 1 : 0;
int sv_id = (int)pvt_data.sv[i].sv;
double cn0 = (double)pvt_data.sv[i].cn0;
uint8_t used_in_fix1 = (pvt_data.sv[i].flags & NRF_MODEM_GNSS_SV_FLAG_USED_IN_FIX) ? 1 : 0;
uint16_t flags = (uint16_t)pvt_data.sv[i].flags;
LOG_INF("SV %d C/N0=%.1f used=%d flags=0x%04x",
(int)pvt_data.sv[i].sv,
(double)pvt_data.sv[i].cn0,
used_in_fix,
(unsigned)pvt_data.sv[i].flags);
}
}
/* Valid fix if 'flags' contains FIX_VALID */
if (pvt_data.flags & NRF_MODEM_GNSS_PVT_FLAG_FIX_VALID)
{
LOG_INF(" FIX: lat=%.6f lon=%.6f alt=%.1f(m) acc=%.1f(m) sv_used=%d sv_view=%d",
pvt_data.latitude,
pvt_data.longitude,
pvt_data.altitude,
pvt_data.accuracy,
sv_used_in_fix(&pvt_data),
sv_in_view(&pvt_data));
LOG_INF("Speed=%.2f(m/s) Heading=%.2f(deg) HDOP=%.2f",
pvt_data.speed,
pvt_data.heading,
pvt_data.hdop);
/* Stop after first valid fix (change this behavior as needed) */
// gps_stop();
// LOG_INF("GNSS stopped after first fix.");
}
else
{
LOG_INF("PVT: searching... sv_view=%d acc=%.1f(m) flags=0x%08x",
sv_in_view(&pvt_data), pvt_data.accuracy, pvt_data.flags);
}
break;
case NRF_MODEM_GNSS_EVT_FIX:
/* FIX event indicates a fix was achieved (PVT will also carry details) */
LOG_INF("NRF_MODEM_GNSS_EVT_FIX");
break;
case NRF_MODEM_GNSS_EVT_NMEA:
/* Optional: read NMEA sentences if enabled */
{
char nmea[256];
err = nrf_modem_gnss_read(nmea, sizeof(nmea), NRF_MODEM_GNSS_DATA_NMEA);
if (err > 0)
{
/* 'err' is number of bytes read */
nmea[MIN(err, (int)sizeof(nmea) - 1)] = '\0';
LOG_INF("NMEA: %s", nmea);
}
}
break;
/* A-GNSS request handling (only if headers provide these enums) */
#if defined(NRF_MODEM_GNSS_EVT_AGPS_REQ) && defined(NRF_MODEM_GNSS_DATA_AGPS_REQ)
case NRF_MODEM_GNSS_EVT_AGPS_REQ:
{
struct nrf_modem_gnss_agps_data_request req = (struct nrf_modem_gnss_agps_data_request){0};
err = nrf_modem_gnss_read(&req, sizeof(req), NRF_MODEM_GNSS_DATA_AGPS_REQ);
if (err)
{
LOG_WRN("A-GNSS req read failed: %d", err);
}
else
{
LOG_INF("A-GNSS requested: utc=%u almanac=%u eph=%u klob=%u neq=%u time=%u pos=%u iono=%u",
req.utc, req.almanac, req.ephemeris, req.klobuchar,
req.nequick, req.system_time, req.position, req.iono);
LOG_INF("Consider fetching assistance (nRF Cloud/SUPL) and injecting.");
}
break;
}
#endif
default:
LOG_INF("GNSS event: %d", event);
break;
}
}
int gnss_setup_and_start(void)
{
int err;
LOG_INF("Entered gnss_setup_and_start starting function");
/* Ensure GPS_EN GPIO device is ready */
#if 0
if (!device_is_ready(gps_en.port))
{
LOG_ERR("GPS_EN GPIO not ready");
return -ENODEV;
}
/* Configure GPS_EN pin as output and turn GPS ON */
err = gpio_pin_configure_dt(&gps_en, GPIO_OUTPUT_ACTIVE);
if (err)
{
LOG_ERR("Failed to configure GPS_EN");
return err;
}
err = gpio_pin_set_dt(&gps_en, 1);
if (err)
{
LOG_ERR("Failed to set GPS_EN");
return err;
}
#endif
LOG_INF("GPS powered ON");
/* LNA/antenna warm-up */
k_msleep(50);
/* Ensure modem is switched to GNSS-only mode before GNSS APIs */
{
char rsp[256] = {0};
int at_err;
/* Query current system mode to avoid unnecessary writes */
at_err = nrf_modem_at_cmd(rsp, sizeof(rsp), "%s", "AT%XSYSTEMMODE?\r\n");
if (at_err)
{
int type = nrf_modem_at_err_type(at_err);
int code = nrf_modem_at_err(at_err);
LOG_WRN("XSYSTEMMODE? failed (type=%d code=%d), proceeding to set", type, code);
}
memset(rsp, 0, sizeof(rsp));
at_err = nrf_modem_at_cmd(rsp, sizeof(rsp), "%s", "AT%XCOEX0=1,1,1565,1586");
if (at_err)
{
LOG_WRN("XCOEX0 set failed: type=%d code=%d ret=%d",
nrf_modem_at_err_type(at_err), nrf_modem_at_err(at_err), at_err);
}
else
{
LOG_INF("XCOEX0 configured for RF coexistence");
}
/* Go to minimum or offline functionality before changing system mode */
at_err = nrf_modem_at_cmd(rsp, sizeof(rsp), "%s", AT_CFUN_OFF_RADIO_CMD);
if (at_err)
{
int type = nrf_modem_at_err_type(at_err);
int code = nrf_modem_at_err(at_err);
LOG_WRN("CFUN=0 failed: type=%d code=%d ret=%d, trying CFUN=4", type, code, at_err);
memset(rsp, 0, sizeof(rsp));
/* Try offline mode */
at_err = nrf_modem_at_cmd(rsp, sizeof(rsp), "%s", AT_CFUN_OFFLINE_CMD);
if (at_err)
{
type = nrf_modem_at_err_type(at_err);
code = nrf_modem_at_err(at_err);
LOG_ERR("CFUN=4 failed: type=%d code=%d ret=%d", type, code, at_err);
return at_err;
}
}
/* Small delay to let modem settle */
k_msleep(200);
/* Set GNSS-only system mode */
memset(rsp, 0, sizeof(rsp));
at_err = nrf_modem_at_cmd(rsp, sizeof(rsp), "%s", AT_COMMAND_SYS_GNSS_ONLY_MODE);
if (at_err)
{
int type = nrf_modem_at_err_type(at_err);
int code = nrf_modem_at_err(at_err);
LOG_ERR("XSYSTEMMODE GNSS-only failed: type=%d code=%d ret=%d", type, code, at_err);
return at_err;
}
/* Enter GNSS-only functional mode */
memset(rsp, 0, sizeof(rsp));
at_err = nrf_modem_at_cmd(rsp, sizeof(rsp), "%s", AT_CFUN_GNSS_ONLY_CMD);
if (at_err)
{
int type = nrf_modem_at_err_type(at_err);
int code = nrf_modem_at_err(at_err);
LOG_ERR("CFUN GNSS-only failed: type=%d code=%d ret=%d", type, code, at_err);
return at_err;
}
LOG_INF("Modem set to GNSS-only mode");
/* GNSS RF routing and coexistence */
if (ENABLE_GNSS_RF_ROUTING)
{
memset(rsp, 0, sizeof(rsp));
at_err = nrf_modem_at_cmd(rsp, sizeof(rsp), "%s", "AT%XMAGPIO=1,1,1,7,0,0");
if (at_err)
{
LOG_WRN("XMAGPIO set failed: type=%d code=%d ret=%d",
nrf_modem_at_err_type(at_err), nrf_modem_at_err(at_err), at_err);
}
else
{
LOG_INF("XMAGPIO configured for GNSS antenna/LNA");
}
memset(rsp, 0, sizeof(rsp));
at_err = nrf_modem_at_cmd(rsp, sizeof(rsp), "%s", "AT%XCOEX0=1,1,0");
if (at_err)
{
LOG_WRN("XCOEX0 set failed: type=%d code=%d ret=%d",
nrf_modem_at_err_type(at_err), nrf_modem_at_err(at_err), at_err);
}
else
{
LOG_INF("XCOEX0 configured for RF coexistence");
}
}
else
{
LOG_INF("Skipping XMAGPIO/XCOEX0");
}
}
// uint32_t mask = NRF_MODEM_GNSS_DELETE_EPHEMERIDES |
// NRF_MODEM_GNSS_DELETE_ALMANACS |
// NRF_MODEM_GNSS_DELETE_IONO_CORRECTION_DATA |
// NRF_MODEM_GNSS_DELETE_UTC_DATA |
// NRF_MODEM_GNSS_DELETE_LAST_GOOD_FIX |
// NRF_MODEM_GNSS_DELETE_GPS_TOW;
// //delets the non-volatile data in the modem to ensure a cold start (clear ephemeris/almanac/assist data for testing)
// err = nrf_modem_gnss_nv_data_delete(mask);
// if (err)
// {
// LOG_WRN("GNSS NV data delete failed: %d", err);
// /* Not fatal—continue */
// }
// else
// {
// LOG_INF("GNSS NV data cleared (cold start).");
// }
/* Register GNSS event handler */
err = nrf_modem_gnss_event_handler_set(gnss_event_handler);
if (err)
{
LOG_ERR("Failed to set GNSS event handler, err=%d", err);
return err;
}
/* Configure fix interval / retry:
* - fix_interval: time between starts of consecutive fix attempts (seconds)
* 0 = continuous tracking
* - fix_retry: how long GNSS tries to get a fix before sleeping (seconds)
* 0 = try forever
*/
err = nrf_modem_gnss_fix_interval_set(0); /* 0 = continuous tracking */
if (err)
{
LOG_ERR("fix_interval_set failed: %d", err);
return err;
}
err = nrf_modem_gnss_fix_retry_set(0); /* 0 = try forever for cold start */
if (err)
{
LOG_ERR("fix_retry_set failed: %d", err);
return err;
}
/* Enable NMEA sentences for visibility (GGA/RMC + satellites GSV/GSA) */
{
uint16_t nmea_mask = NRF_MODEM_GNSS_NMEA_GGA_MASK |
NRF_MODEM_GNSS_NMEA_RMC_MASK |
NRF_MODEM_GNSS_NMEA_GSV_MASK |
NRF_MODEM_GNSS_NMEA_GSA_MASK;
err = nrf_modem_gnss_nmea_mask_set(nmea_mask);
if (err)
{
LOG_WRN("nmea_mask_set failed: %d", err);
}
/* Optional GNSS performance tuning */
(void)nrf_modem_gnss_use_case_set(NRF_MODEM_GNSS_USE_CASE_MULTIPLE_HOT_START |
NRF_MODEM_GNSS_USE_CASE_LOW_ACCURACY);
// Increase warm‑up time if using an external active antenna or LNA, as they may require more time to stabilize and provide optimal performance.
k_msleep(50);
/* Start GNSS */
err = nrf_modem_gnss_start();
if (err)
{
LOG_ERR("Failed to start GNSS, err=%d", err);
return err;
}
LOG_INF("GNSS started.");
return 0;
}
}
/* Stop GPS */
void gps_stop(void)
{
LOG_INF("Stopping GPS");
nrf_modem_gnss_stop();
}
Regards,
Gunjan
Hi,
If you see the above picture, we are configuring COEX0 pin before the RF is enabled. Please go through the code gps.c in the attachment.
You referred terminal_logsOpen1.log for modem logs ?
Regards,
Karthik.
