NEO-6M GPS module implementation file. More...

#include <stdint.h>
#include "neo6.h"
#include "cmd.h"
#include "common.h"
#include "err.h"
#include "init.h"
#include "log.h"
#include "modules.h"
#include "stm32f401re_gpio.h"
#include "stm32f401re_usart.h"
#include "cbuf.h"
#include "configuration.h"

Include dependency graph for neo6.c:

Go to the source code of this file.

Classes
struct	neo6_handle_s
	Internal structure representing the NEO-6 hardware instance. More...
struct	internal_state_s
	Internal state of the SysTick driver. More...

Macros
#define	VTG_TMG_T_DEGREE_POS 1
#define	VTG_TMG_T_POS 2
#define	VTG_TMG_M_DEGREE_POS 3
#define	VTG_TMG_M_POS 4
#define	VTG_SPEED_KNOTS_POS 5
#define	VTG_SPEED_N_POS 6
#define	VTG_SPEED_OVER_GROUND_POS 7
#define	VTG_SPEED_OVER_GROUND_K_POS 8
#define	VTG_MODE_INDICATOR_POS 9
#define	GGA_UTC_POS 1
#define	GGA_LAT_POS 2
#define	GGA_LAT_DIR_POS 3
#define	GGA_LON_POS 4
#define	GGA_LON_DIR_POS 5
#define	GGA_QUALITY_FIX_POS 6
#define	GGA_NUM_SATS_POS 7
#define	GGA_HDOP_POS 8
#define	GGA_ORTH_HEIGHT_POS 9
#define	GGA_ORTH_HEIGHT_UNIT_POS 10
#define	GGA_GEOID_SEP_POS 11
#define	GGA_GEOID_SEP_UNIT_POS 12
#define	GGA_DATA_REC_AGE_POS 13
#define	GGA_REF_STAT_ID_POS 14
#define	GSA_MODE_POS 1
#define	GSA_FIX_TYPE_POS 2
#define	GSA_PRN_NUM_POS 3
#define	GSA_PDOP_POS 15
#define	GSA_HDOP_POS 16
#define	GSA_VDOP_POS 17
#define	GSV_NUM_OF_MESSAGES_POS 1
#define	GSV_NUM_OF_THIS_MESSAGE_POS 2
#define	GSV_NUM_SATS_VISIBLE_POS 3
#define	GSV_SV_PRN_NUM_POS 4
#define	GSV_ELEVATION_POS 5
#define	GSV_AZIMUTH_POS 6
#define	GSV_SNR_POS 7

Functions
static ERR_te	neo6_calc_checksum (char msg, uint32_t msg_len, uint8_t checksum_o)
	Computes the NMEA checksum of a sentence by XORing all bytes between '$' and '*'.
static ERR_te	neo6_process_msg (uint8_t *msg, uint32_t msg_len)
	Verifies the checksum of a received NMEA sentence and dispatches it to the appropriate parser.
static ERR_te	neo6_process_rmc (char **tokens)
	Parses an RMC sentence and updates time, date, latitude, and longitude.
static ERR_te	neo6_process_vtg (char **tokens)
	Parses a VTG sentence and updates movement direction and speed.
static ERR_te	neo6_process_gga (char **tokens)
	Parses a GGA sentence and updates fix status, satellites used, orthometric height, and geoid separation.
static ERR_te	neo6_process_gsa (char **tokens)
	Parses a GSA sentence and updates fix type, PDOP, HDOP, and VDOP.
static ERR_te	neo6_process_gsv (char **tokens)
	Parses a GSV sentence and updates the total satellite count.
static ERR_te	neo6_dumpnmea_handler (uint32_t argc, char **argv)
	CLI handler for the "dumpnmea" command. Enables or disables raw NMEA logging.
ERR_te	neo6_init_subsys (void)
	Initializes the NEO-6 subsystem.
ERR_te	neo6_deinit_subsys (void)
	Deinitializes the NEO-6 subsystem.
ERR_te	neo6_start_subsys (void)
	Starts the NEO-6 subsystem.
ERR_te	neo6_stop_subsys (void)
	Stops the NEO-6 subsystem.
ERR_te	neo6_init_handle (NEO6_CFG_ts neo6_cfg, NEO6_HANDLE_ts *neo6_handle_o)
	Initializes the NEO-6 hardware handle.
ERR_te	neo6_run (void)
	Processes received NMEA data.
ERR_te	neo6_get_info (NEO6_INFO_ts **neo6_info_o)
	Returns a pointer to the internal GPS data structure.
void	usart6_irq_data_recv_callback (uint8_t data)
	USART RXNE interrupt callback. Writes the received byte into the USART receive buffer.

Variables
static uint8_t	usart_data_recv_cbuf_mem [128]
	Backing memory for the USART receive circular buffer.
static uint8_t	nmea_cbuf_mem [128]
	Backing memory for the NMEA sentence accumulation buffer.
static struct internal_state_s	internal_state
	Singleton instance of the NEO-6 subsystem internal state.
static CMD_INFO_ts	neo6_cmds []
	Table of CLI commands registered by the NEO-6 subsystem.
static CMD_CLIENT_INFO_ts	neo6_cmd_client_info
	Registration descriptor passed to the command subsystem.

Detailed Description

NEO-6M GPS module implementation file.

Author: github.com/Baksi675

Version: 0.1

Date: 2026-02-03

Copyright: Copyright (c) 2026

Definition in file neo6.c.

Macro Definition Documentation

◆ VTG_TMG_T_DEGREE_POS

#define VTG_TMG_T_DEGREE_POS 1

Track made good in degrees relative to true north.

Definition at line 27 of file neo6.c.

◆ VTG_TMG_T_POS

#define VTG_TMG_T_POS 2

True north indicator.

Definition at line 28 of file neo6.c.

◆ VTG_TMG_M_DEGREE_POS

#define VTG_TMG_M_DEGREE_POS 3

Track made good in degrees relative to magnetic north.

Definition at line 29 of file neo6.c.

◆ VTG_TMG_M_POS

#define VTG_TMG_M_POS 4

Magnetic north indicator.

Definition at line 30 of file neo6.c.

◆ VTG_SPEED_KNOTS_POS

#define VTG_SPEED_KNOTS_POS 5

Speed over ground in knots.

Definition at line 31 of file neo6.c.

◆ VTG_SPEED_N_POS

#define VTG_SPEED_N_POS 6

Knots indicator.

Definition at line 32 of file neo6.c.

◆ VTG_SPEED_OVER_GROUND_POS

#define VTG_SPEED_OVER_GROUND_POS 7

Speed over ground in kph.

Definition at line 33 of file neo6.c.

◆ VTG_SPEED_OVER_GROUND_K_POS

#define VTG_SPEED_OVER_GROUND_K_POS 8

Kph indicator.

Definition at line 34 of file neo6.c.

◆ VTG_MODE_INDICATOR_POS

#define VTG_MODE_INDICATOR_POS 9

Mode indicator.

Definition at line 35 of file neo6.c.

◆ GGA_UTC_POS

#define GGA_UTC_POS 1

UTC time.

Definition at line 38 of file neo6.c.

◆ GGA_LAT_POS

#define GGA_LAT_POS 2

Latitude.

Definition at line 39 of file neo6.c.

◆ GGA_LAT_DIR_POS

#define GGA_LAT_DIR_POS 3

Latitude hemisphere direction.

Definition at line 40 of file neo6.c.

◆ GGA_LON_POS

#define GGA_LON_POS 4

Longitude.

Definition at line 41 of file neo6.c.

◆ GGA_LON_DIR_POS

#define GGA_LON_DIR_POS 5

Longitude hemisphere direction.

Definition at line 42 of file neo6.c.

◆ GGA_QUALITY_FIX_POS

#define GGA_QUALITY_FIX_POS 6

Fix quality indicator.

Definition at line 43 of file neo6.c.

◆ GGA_NUM_SATS_POS

#define GGA_NUM_SATS_POS 7

Number of satellites used for the fix.

Definition at line 44 of file neo6.c.

◆ GGA_HDOP_POS

#define GGA_HDOP_POS 8

Horizontal dilution of precision.

Definition at line 45 of file neo6.c.

◆ GGA_ORTH_HEIGHT_POS

#define GGA_ORTH_HEIGHT_POS 9

Orthometric height above mean sea level.

Definition at line 46 of file neo6.c.

◆ GGA_ORTH_HEIGHT_UNIT_POS

#define GGA_ORTH_HEIGHT_UNIT_POS 10

Unit of orthometric height.

Definition at line 47 of file neo6.c.

◆ GGA_GEOID_SEP_POS

#define GGA_GEOID_SEP_POS 11

Geoid separation.

Definition at line 48 of file neo6.c.

◆ GGA_GEOID_SEP_UNIT_POS

#define GGA_GEOID_SEP_UNIT_POS 12

Unit of geoid separation.

Definition at line 49 of file neo6.c.

◆ GGA_DATA_REC_AGE_POS

#define GGA_DATA_REC_AGE_POS 13

Age of differential GPS data record.

Definition at line 50 of file neo6.c.

◆ GGA_REF_STAT_ID_POS

#define GGA_REF_STAT_ID_POS 14

Reference station ID.

Definition at line 51 of file neo6.c.

◆ GSA_MODE_POS

#define GSA_MODE_POS 1

Selection mode: automatic or manual.

Definition at line 54 of file neo6.c.

◆ GSA_FIX_TYPE_POS

#define GSA_FIX_TYPE_POS 2

Fix type: 1 = none, 2 = 2D, 3 = 3D.

Definition at line 55 of file neo6.c.

◆ GSA_PRN_NUM_POS

#define GSA_PRN_NUM_POS 3

SV pseudorandom noise code number.

Definition at line 56 of file neo6.c.

◆ GSA_PDOP_POS

#define GSA_PDOP_POS 15

Position dilution of precision.

Definition at line 57 of file neo6.c.

◆ GSA_HDOP_POS

#define GSA_HDOP_POS 16

Horizontal dilution of precision.

Definition at line 58 of file neo6.c.

◆ GSA_VDOP_POS

#define GSA_VDOP_POS 17

Vertical dilution of precision.

Definition at line 59 of file neo6.c.

◆ GSV_NUM_OF_MESSAGES_POS

#define GSV_NUM_OF_MESSAGES_POS 1

Total number of GSV messages in this cycle.

Definition at line 62 of file neo6.c.

◆ GSV_NUM_OF_THIS_MESSAGE_POS

#define GSV_NUM_OF_THIS_MESSAGE_POS 2

Message number within the cycle.

Definition at line 63 of file neo6.c.

◆ GSV_NUM_SATS_VISIBLE_POS

#define GSV_NUM_SATS_VISIBLE_POS 3

Total number of satellites in view.

Definition at line 64 of file neo6.c.

◆ GSV_SV_PRN_NUM_POS

#define GSV_SV_PRN_NUM_POS 4

Satellite PRN number.

Definition at line 65 of file neo6.c.

◆ GSV_ELEVATION_POS

#define GSV_ELEVATION_POS 5

Satellite elevation in degrees (max 90).

Definition at line 66 of file neo6.c.

◆ GSV_AZIMUTH_POS

#define GSV_AZIMUTH_POS 6

Azimuth in degrees from true north (000–359).

Definition at line 67 of file neo6.c.

◆ GSV_SNR_POS

#define GSV_SNR_POS 7

Signal-to-noise ratio in dB (null when not tracking).

Definition at line 68 of file neo6.c.

Variable Documentation

◆ usart_data_recv_cbuf_mem

uint8_t usart_data_recv_cbuf_mem[128]

static

Backing memory for the USART receive circular buffer.

Written by the USART ISR callback and drained by neo6_run.

Definition at line 75 of file neo6.c.

◆ nmea_cbuf_mem

uint8_t nmea_cbuf_mem[128]

static

Backing memory for the NMEA sentence accumulation buffer.

Accumulates bytes from the USART buffer until a complete NMEA sentence (terminated by '\n') is available for processing.

Definition at line 83 of file neo6.c.

◆ internal_state

struct internal_state_s internal_state

static

Singleton instance of the NEO-6 subsystem internal state.

Definition at line 156 of file neo6.c.

◆ neo6_cmds

CMD_INFO_ts neo6_cmds[]

static

Initial value:

= {
    {
        .name = "dumpnmea",
        .help = "Dumps raw NMEA messages, usage: neo6 dumpnmea <true|false>",
        .handler = neo6_dumpnmea_handler
    },
}

Table of CLI commands registered by the NEO-6 subsystem.

Registered with the command subsystem via neo6_cmd_client_info during neo6_init_subsys.

Definition at line 177 of file neo6.c.

                                 {
    {
        .name = "dumpnmea",
        .help = "Dumps raw NMEA messages, usage: neo6 dumpnmea <true|false>",
        .handler = neo6_dumpnmea_handler
    },
};

◆ neo6_cmd_client_info

CMD_CLIENT_INFO_ts neo6_cmd_client_info

static

Initial value:

= {
    .cmds_ptr = neo6_cmds,
    .num_cmds = sizeof(neo6_cmds) / sizeof(neo6_cmds[0]),
    .name = "neo6",
    .log_level_ptr = &internal_state.log_level
}

Registration descriptor passed to the command subsystem.

Bundles the command table, its size, the subsystem name prefix used on the CLI, and a pointer to the runtime log-level variable.

Definition at line 192 of file neo6.c.

                                                 {
    .cmds_ptr = neo6_cmds,
    .num_cmds = sizeof(neo6_cmds) / sizeof(neo6_cmds[0]),
    .name = "neo6",
    .log_level_ptr = &internal_state.log_level
};

Classes

Macros

Functions

Variables

Detailed Description

Macro Definition Documentation

◆ VTG_TMG_T_DEGREE_POS

◆ VTG_TMG_T_POS

◆ VTG_TMG_M_DEGREE_POS

◆ VTG_TMG_M_POS

◆ VTG_SPEED_KNOTS_POS

◆ VTG_SPEED_N_POS

◆ VTG_SPEED_OVER_GROUND_POS

◆ VTG_SPEED_OVER_GROUND_K_POS

◆ VTG_MODE_INDICATOR_POS

◆ GGA_UTC_POS

◆ GGA_LAT_POS

◆ GGA_LAT_DIR_POS

◆ GGA_LON_POS

◆ GGA_LON_DIR_POS

◆ GGA_QUALITY_FIX_POS

◆ GGA_NUM_SATS_POS

◆ GGA_HDOP_POS

◆ GGA_ORTH_HEIGHT_POS

◆ GGA_ORTH_HEIGHT_UNIT_POS

◆ GGA_GEOID_SEP_POS

◆ GGA_GEOID_SEP_UNIT_POS

◆ GGA_DATA_REC_AGE_POS

◆ GGA_REF_STAT_ID_POS

◆ GSA_MODE_POS

◆ GSA_FIX_TYPE_POS

◆ GSA_PRN_NUM_POS

◆ GSA_PDOP_POS

◆ GSA_HDOP_POS

◆ GSA_VDOP_POS

◆ GSV_NUM_OF_MESSAGES_POS

◆ GSV_NUM_OF_THIS_MESSAGE_POS

◆ GSV_NUM_SATS_VISIBLE_POS

◆ GSV_SV_PRN_NUM_POS

◆ GSV_ELEVATION_POS

◆ GSV_AZIMUTH_POS

◆ GSV_SNR_POS

Variable Documentation

◆ usart_data_recv_cbuf_mem

◆ nmea_cbuf_mem

◆ internal_state

◆ neo6_cmds

◆ neo6_cmd_client_info