gps: add generic nmea driver

src/drivers/drv_sensor.h

@@ -193,6 +193,7 @@
 #define DRV_GPS_DEVTYPE_UBX_8   0xA8
 #define DRV_GPS_DEVTYPE_UBX_9   0xA9
 #define DRV_GPS_DEVTYPE_UBX_F9P 0xAA
+#define DRV_GPS_DEVTYPE_NMEA 0xAB
 
 #define DRV_GPS_DEVTYPE_SIM 0xAF
 

src/drivers/gps/CMakeLists.txt

@@ -48,6 +48,7 @@ px4_add_module(
 		devices/src/rtcm.cpp
 		devices/src/emlid_reach.cpp
 		devices/src/femtomes.cpp
+		devices/src/nmea.cpp
 	MODULE_CONFIG
 		module.yaml
 	DEPENDS

src/drivers/gps/gps.cpp

@@ -68,6 +68,7 @@
 # include "devices/src/emlid_reach.h"
 # include "devices/src/mtk.h"
 # include "devices/src/femtomes.h"
+# include "devices/src/nmea.h"
 #endif // CONSTRAINED_FLASH
 #include "devices/src/ubx.h"
 
@@ -85,7 +86,8 @@ enum class gps_driver_mode_t {
 	MTK,
 	ASHTECH,
 	EMLIDREACH,
-	FEMTOMES
+	FEMTOMES,
+	NMEA
 };
 
 enum class gps_dump_comm_mode_t : int32_t {
@@ -321,6 +323,8 @@ GPS::GPS(const char *path, gps_driver_mode_t mode, GPSHelper::Interface interfac
 		case 4: _mode = gps_driver_mode_t::EMLIDREACH; break;
 
 		case 5: _mode = gps_driver_mode_t::FEMTOMES; break;
+
+		case 6: _mode = gps_driver_mode_t::NMEA; break;
 #endif // CONSTRAINED_FLASH
 		}
 	}
@@ -793,6 +797,11 @@ GPS::run()
 			_helper = new GPSDriverFemto(&GPS::callback, this, &_report_gps_pos, _p_report_sat_info, heading_offset);
 			set_device_type(DRV_GPS_DEVTYPE_FEMTOMES);
 			break;
+
+		case gps_driver_mode_t::NMEA:
+			_helper = new GPSDriverNMEA(&GPS::callback, this, &_report_gps_pos, _p_report_sat_info, heading_offset);
+			set_device_type(DRV_GPS_DEVTYPE_NMEA);
+			break;
 #endif // CONSTRAINED_FLASH
 
 		default:
@@ -953,6 +962,7 @@ GPS::run()
 				break;
 
 			case gps_driver_mode_t::FEMTOMES:
+			case gps_driver_mode_t::NMEA: // skip NMEA for auto-detection to avoid false positive matching
 #endif // CONSTRAINED_FLASH
 				_mode = gps_driver_mode_t::UBX;
 				px4_usleep(500000); // tried all possible drivers. Wait a bit before next round
@@ -1009,6 +1019,10 @@ GPS::print_status()
 	case gps_driver_mode_t::FEMTOMES:
 		PX4_INFO("protocol: FEMTOMES");
 		break;
+
+	case gps_driver_mode_t::NMEA:
+		PX4_INFO("protocol: NMEA");
+		break;
 #endif // CONSTRAINED_FLASH
 
 	default:
@@ -1175,7 +1189,7 @@ $ gps reset warm
 
 	PRINT_MODULE_USAGE_PARAM_STRING('i', "uart", "spi|uart", "GPS interface", true);
 	PRINT_MODULE_USAGE_PARAM_STRING('j', "uart", "spi|uart", "secondary GPS interface", true);
-	PRINT_MODULE_USAGE_PARAM_STRING('p', nullptr, "ubx|mtk|ash|eml|fem", "GPS Protocol (default=auto select)", true);
+	PRINT_MODULE_USAGE_PARAM_STRING('p', nullptr, "ubx|mtk|ash|eml|fem|nmea", "GPS Protocol (default=auto select)", true);
 
 	PRINT_MODULE_USAGE_DEFAULT_COMMANDS();
 	PRINT_MODULE_USAGE_COMMAND_DESCR("reset", "Reset GPS device");
@@ -1319,6 +1333,9 @@ GPS *GPS::instantiate(int argc, char *argv[], Instance instance)
 
 			} else if (!strcmp(myoptarg, "fem")) {
 				mode = gps_driver_mode_t::FEMTOMES;
+
+			} else if (!strcmp(myoptarg, "nmea")) {
+				mode = gps_driver_mode_t::NMEA;
 #endif // CONSTRAINED_FLASH
 			} else {
 				PX4_ERR("unknown protocol: %s", myoptarg);

src/drivers/gps/params.c

@@ -127,6 +127,7 @@ PARAM_DEFINE_FLOAT(GPS_YAW_OFFSET, 0.f);
  * @value 3 Ashtech / Trimble
  * @value 4 Emlid Reach
  * @value 5 Femtomes
+ * @value 6 NMEA (generic)
  *
  * @reboot_required true
  * @group GPS
@@ -148,6 +149,7 @@ PARAM_DEFINE_INT32(GPS_1_PROTOCOL, 1);
  * @value 3 Ashtech / Trimble
  * @value 4 Emlid Reach
  * @value 5 Femtomes
+ * @value 6 NMEA (generic)
  *
  * @reboot_required true
  * @group GPS