ESP32/components/gps_sync/gps_sync.c

318 lines
10 KiB
C

#include "gps_sync.h"
#include "driver/gpio.h"
#include "driver/uart.h"
#include "esp_timer.h"
#include "esp_log.h"
#include "esp_rom_sys.h"
#include <string.h>
#include <time.h>
#include <stdarg.h>
#include <stdio.h>
#include <assert.h>
#include <inttypes.h> // Required for PRIu64
// --- SAFE WIRING FOR ESP32-C5 ---
#define GPS_UART_NUM UART_NUM_1
#define GPS_RX_PIN GPIO_NUM_23
#define GPS_TX_PIN GPIO_NUM_24
#define PPS_GPIO GPIO_NUM_25
#define GPS_BAUD_RATE 9600
#define UART_BUF_SIZE 1024
static const char *TAG = "GPS_SYNC";
// GPS sync state
static int64_t monotonic_offset_us = 0;
static volatile int64_t last_pps_monotonic = 0;
static volatile time_t next_pps_gps_second = 0;
static bool gps_has_fix = false;
static bool use_gps_for_logs = false;
static SemaphoreHandle_t sync_mutex;
// Force update flag (defaults to true so boot-up snaps immediately)
static volatile bool force_sync_update = true;
// PPS interrupt - captures exact monotonic time at second boundary
static void IRAM_ATTR pps_isr_handler(void* arg) {
static bool onetime = true;
last_pps_monotonic = esp_timer_get_time();
if (onetime) {
esp_rom_printf("PPS connected!\n");
onetime = false;
}
}
// Parse GPS time from NMEA sentence
static bool parse_gprmc(const char* nmea, struct tm* tm_out, bool* valid) {
if (strncmp(nmea, "$GPRMC", 6) != 0 && strncmp(nmea, "$GNRMC", 6) != 0) {
return false;
}
char *p = strchr(nmea, ',');
if (!p) return false;
// Time field
p++;
int hour, min, sec;
if (sscanf(p, "%2d%2d%2d", &hour, &min, &sec) != 3) {
return false;
}
// Status field (A=valid, V=invalid)
p = strchr(p, ',');
if (!p) return false;
p++;
*valid = (*p == 'A');
// Skip to date field (8 commas ahead from time)
for (int i = 0; i < 7; i++) {
p = strchr(p, ',');
if (!p) return false;
p++;
}
// Date field: ddmmyy
int day, month, year;
if (sscanf(p, "%2d%2d%2d", &day, &month, &year) != 3) {
return false;
}
year += (year < 80) ? 2000 : 1900;
tm_out->tm_sec = sec;
tm_out->tm_min = min;
tm_out->tm_hour = hour;
tm_out->tm_mday = day;
tm_out->tm_mon = month - 1;
tm_out->tm_year = year - 1900;
tm_out->tm_isdst = 0;
return true;
}
// Force the next GPS update to snap immediately (bypass filter)
void gps_force_next_update(void) {
force_sync_update = true;
ESP_LOGW(TAG, "Requesting forced GPS sync update");
}
// GPS processing task
static void gps_task(void* arg) {
char line[128];
int pos = 0;
while (1) {
uint8_t data;
int len = uart_read_bytes(GPS_UART_NUM, &data, 1, 100 / portTICK_PERIOD_MS);
if (len > 0) {
if (data == '\n') {
line[pos] = '\0';
struct tm gps_tm;
bool valid;
if (parse_gprmc(line, &gps_tm, &valid)) {
if (valid) {
time_t gps_time = mktime(&gps_tm);
xSemaphoreTake(sync_mutex, portMAX_DELAY);
next_pps_gps_second = gps_time + 1;
xSemaphoreGive(sync_mutex);
vTaskDelay(pdMS_TO_TICKS(300));
xSemaphoreTake(sync_mutex, portMAX_DELAY);
if (last_pps_monotonic > 0) {
int64_t gps_us = (int64_t)next_pps_gps_second * 1000000LL;
int64_t new_offset = gps_us - last_pps_monotonic;
if (monotonic_offset_us == 0 || force_sync_update) {
monotonic_offset_us = new_offset;
if (force_sync_update) {
ESP_LOGW(TAG, "GPS sync SNAP: Offset forced to %lld us", monotonic_offset_us);
force_sync_update = false;
}
} else {
// Low-pass filter: 90% old + 10% new
monotonic_offset_us = (monotonic_offset_us * 9 + new_offset) / 10;
}
gps_has_fix = true;
ESP_LOGI(TAG, "GPS sync: %04d-%02d-%02d %02d:%02d:%02d, offset=%lld us",
gps_tm.tm_year + 1900, gps_tm.tm_mon + 1, gps_tm.tm_mday,
gps_tm.tm_hour, gps_tm.tm_min, gps_tm.tm_sec,
monotonic_offset_us);
}
xSemaphoreGive(sync_mutex);
} else {
gps_has_fix = false;
}
}
pos = 0;
} else if (pos < sizeof(line) - 1) {
line[pos++] = data;
}
}
}
}
void gps_sync_init(bool use_gps_log_timestamps) {
ESP_LOGI(TAG, "Initializing GPS sync");
use_gps_for_logs = use_gps_log_timestamps;
// Ensure we start with a forced update
gps_force_next_update();
if (use_gps_log_timestamps) {
ESP_LOGI(TAG, "ESP_LOG timestamps: GPS time in seconds.milliseconds format");
// Override vprintf to add decimal point to timestamps
esp_log_set_vprintf(gps_log_vprintf);
}
sync_mutex = xSemaphoreCreateMutex();
uart_config_t uart_config = {
.baud_rate = GPS_BAUD_RATE,
.data_bits = UART_DATA_8_BITS,
.parity = UART_PARITY_DISABLE,
.stop_bits = UART_STOP_BITS_1,
.flow_ctrl = UART_HW_FLOWCTRL_DISABLE,
.source_clk = UART_SCLK_DEFAULT,
};
ESP_ERROR_CHECK(uart_driver_install(GPS_UART_NUM, UART_BUF_SIZE, 0, 0, NULL, 0));
ESP_ERROR_CHECK(uart_param_config(GPS_UART_NUM, &uart_config));
ESP_ERROR_CHECK(uart_set_pin(GPS_UART_NUM, GPS_TX_PIN, GPS_RX_PIN,
UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE));
gpio_config_t io_conf = {
.intr_type = GPIO_INTR_POSEDGE,
.mode = GPIO_MODE_INPUT,
.pin_bit_mask = (1ULL << PPS_GPIO),
.pull_up_en = GPIO_PULLUP_ENABLE,
.pull_down_en = GPIO_PULLDOWN_DISABLE,
};
ESP_ERROR_CHECK(gpio_config(&io_conf));
ESP_ERROR_CHECK(gpio_install_isr_service(0));
ESP_ERROR_CHECK(gpio_isr_handler_add(PPS_GPIO, pps_isr_handler, NULL));
xTaskCreate(gps_task, "gps_task", 4096, NULL, 5, NULL);
ESP_LOGI(TAG, "GPS sync initialized (RX=GPIO%d, PPS=GPIO%d)", GPS_RX_PIN, PPS_GPIO);
}
gps_timestamp_t gps_get_timestamp(void) {
gps_timestamp_t ts;
// Using clock_gettime (POSIX standard, portable)
clock_gettime(CLOCK_MONOTONIC, &ts.mono_ts);
xSemaphoreTake(sync_mutex, portMAX_DELAY);
// Convert timespec to microseconds
ts.monotonic_us = (int64_t)ts.mono_ts.tv_sec * 1000000LL +
ts.mono_ts.tv_nsec / 1000;
// Convert to milliseconds
ts.monotonic_ms = ts.monotonic_us / 1000;
// Calculate GPS time
ts.gps_us = ts.monotonic_us + monotonic_offset_us;
ts.gps_ms = ts.gps_us / 1000;
ts.synced = gps_has_fix;
xSemaphoreGive(sync_mutex);
return ts;
}
int64_t gps_get_monotonic_ms(void) {
struct timespec ts;
clock_gettime(CLOCK_MONOTONIC, &ts);
return (int64_t)ts.tv_sec * 1000LL + ts.tv_nsec / 1000000;
}
bool gps_is_synced(void) {
return gps_has_fix;
}
// ---------------- LOGGING SYSTEM INTERCEPTION ----------------
// We now only return standard system time (ms) to ESP-IDF.
// We do NOT return GPS time here because it overflows 32 bits.
uint32_t gps_log_timestamp(void) {
return (uint32_t)(esp_timer_get_time() / 1000ULL);
}
// Intercepts the log line string before it is printed.
// It detects the timestamp `(1234)` which is monotonic ms,
// and mathematically converts it to `(+17544234.123)` GPS sec.ms
int gps_log_vprintf(const char *fmt, va_list args) {
static char buffer[512];
// Format the message into our buffer
int ret = vsnprintf(buffer, sizeof(buffer), fmt, args);
assert(ret >= 0);
if (use_gps_for_logs) {
// Look for timestamp pattern: "I (", "W (", etc.
char *timestamp_start = NULL;
for (int i = 0; buffer[i] != '\0' && i < sizeof(buffer) - 20; i++) {
if ((buffer[i] == 'I' || buffer[i] == 'W' || buffer[i] == 'E' ||
buffer[i] == 'D' || buffer[i] == 'V') &&
buffer[i+1] == ' ' && buffer[i+2] == '(') {
timestamp_start = &buffer[i+3];
break;
}
}
if (timestamp_start) {
char *timestamp_end = strchr(timestamp_start, ')');
if (timestamp_end) {
// Parse the MONOTONIC ms that ESP-IDF put there
uint32_t monotonic_log_ms = 0;
if (sscanf(timestamp_start, "%lu", &monotonic_log_ms) == 1) {
char reformatted[512];
size_t prefix_len = timestamp_start - buffer;
memcpy(reformatted, buffer, prefix_len);
int decimal_len = 0;
if (gps_has_fix) {
// MATH: Calculate GPS time based on the log's monotonic time
int64_t log_mono_us = (int64_t)monotonic_log_ms * 1000;
int64_t log_gps_us = log_mono_us + monotonic_offset_us;
// Split into Seconds and Milliseconds
uint64_t gps_sec = log_gps_us / 1000000;
uint32_t gps_ms = (log_gps_us % 1000000) / 1000;
decimal_len = snprintf(reformatted + prefix_len,
sizeof(reformatted) - prefix_len,
"+%" PRIu64 ".%03lu", gps_sec, gps_ms);
} else {
// No fix: just show monotonic nicely
uint32_t sec = monotonic_log_ms / 1000;
uint32_t ms = monotonic_log_ms % 1000;
decimal_len = snprintf(reformatted + prefix_len,
sizeof(reformatted) - prefix_len,
"*%lu.%03lu", sec, ms);
}
// Copy the rest of the message (from the closing parenthesis onwards)
strcpy(reformatted + prefix_len + decimal_len, timestamp_end);
return printf("%s", reformatted);
}
}
}
}
return printf("%s", buffer);
}