Add comprehensive error tracking and browsing system

This commit implements a new global error tracking mechanism that
complements the existing System.status error handling. Errors are now
logged persistently in System.global_error and can be browsed and
manually reset by the user.

## Architecture Changes

### Dual Error Recording
- File access errors now set BOTH System.status (for control flow)
  and System.global_error (for persistent logging)
- System.status continues to trigger loop breaks and reinitializations
- System.global_error accumulates errors via bitwise OR for user review
- This hybrid approach maintains existing critical error behavior while
  adding error history tracking

### New Error Types Added to System.global_error
- ERROR_TEMPERATURE (4): Temperature sensor failure
- ERROR_DISK (8): SD card mount/access errors
- ERROR_FILE_WRITE (16): File write failures
- ERROR_FILE_SYNC (32): FAT sync errors
- ERROR_FILE_CLOSE (64): File close failures
- ERROR_FILE_OPEN (128): File open failures
- Existing: ERROR_I2C, ERROR_I2C_TIMEOUT

## Menu System Enhancements

### New Menu Type: MENU_TYPE_FUNCTION_WITH_KEY
- Extends menu system to handle arbitrary key presses
- Function receives key code as parameter: func_key(unsigned char k)
- Uses anonymous union with existing func pointer (no RAM overhead)
- Enables custom key handling within menu items

### Error Browser Interface
- Added as last item in default_menu (main screen rotation)
- LEFT/RIGHT arrows: Navigate between multiple errors
- UP+DOWN simultaneously: Reset all errors
- Display format: "<1/3> Error name" when multiple errors present
- Shows "Brak" (None) when no errors

## Implementation Details

### Auto-Jump to Error Screen
- check_error_and_jump(): Monitors for new errors in main loop
- Automatically jumps to error display when error transitions from
  ERROR_NO to any error state
- Only activates when viewing default_menu (main screens)
- Preserves user context when in submenus

### Temperature Sensor Monitoring
- Checks System.temperature_ok after GPS initialization
- Waits for F_GPSOK flag to avoid false positives at startup
- Sets ERROR_TEMPERATURE flag when sensor fails after warmup

### Error Browser State Machine
- Maintains current error index and total error count
- Dynamically counts active errors from bitfield
- Wraps navigation at boundaries
- Resets state when all errors cleared

### Time Display Improvements
- Added format_time() helper for human-readable time formatting
- Converts seconds to XhXXmXXs format with automatic scaling:
  * <1 min: "XXs"
  * <1 hour: "XXmXXs"
  * <10 hours: "XhXXmXXs"
  * ≥10 hours: "XXhXXm" (seconds dropped to fit display)
- Uses unsigned char for mins/secs (8-bit optimization)
- Applied to track time (display.c:242) and pause time (display.c:250)

## Memory Optimization
- Anonymous union in struct menu_pos saves 2 bytes per menu item
- Static error_browser struct: 2 bytes total
- Error list table stored in flash memory (__flash const)

## User Interface
Navigation in error screen:
  ← → : Browse multiple errors
  ↑ + ↓ : Reset all errors (press simultaneously)
  Single ↑/↓ : Navigate out of error screen (standard menu behavior)

The simultaneous UP+DOWN press works because the combined key value
(K_UP | K_DOWN) doesn't match individual case statements in menu
navigation, allowing it to pass through to the custom handler.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

soft/display.c

@@ -309,6 +309,93 @@ void disp_func_temperature(void) {
 	}
 }
 
+static struct {
+	unsigned char index;
+	unsigned char count;
+} error_browser;
+
+static __flash const struct {
+	unsigned int flag;
+	__flash const char *name;
+} error_list[] = {
+	{ERROR_TEMPERATURE, PSTR("Czujnik temp.")},
+	{ERROR_I2C, PSTR("I2C")},
+	{ERROR_I2C_TIMEOUT, PSTR("I2C timeout")},
+	{ERROR_DISK, PSTR("Blad karty")},
+	{ERROR_FILE_WRITE, PSTR("Blad zapisu")},
+	{ERROR_FILE_SYNC, PSTR("Blad zapisu FAT")},
+	{ERROR_FILE_CLOSE, PSTR("Blad zamk.pliku")},
+	{ERROR_FILE_OPEN, PSTR("Blad otw. pliku")},
+};
+
+void disp_func_global_error(void) {
+	unsigned char i, found_index = 0;
+
+	disp_line1(PSTR("*** BLAD ***"));
+
+	if (System.global_error == ERROR_NO) {
+		disp_line2(PSTR("Brak"));
+		error_browser.count = 0;
+		error_browser.index = 0;
+		return;
+	}
+
+	/* Count errors and find current one */
+	error_browser.count = 0;
+	for (i = 0; i < sizeof(error_list)/sizeof(error_list[0]); i++) {
+		if (System.global_error & error_list[i].flag) {
+			if (error_browser.count == error_browser.index) {
+				found_index = i;
+			}
+			error_browser.count++;
+		}
+	}
+
+	/* Wrap index if needed */
+	if (error_browser.index >= error_browser.count) {
+		error_browser.index = 0;
+		found_index = 0;
+		for (i = 0; i < sizeof(error_list)/sizeof(error_list[0]); i++) {
+			if (System.global_error & error_list[i].flag) {
+				found_index = i;
+				break;
+			}
+		}
+	}
+
+	/* Display current error */
+	if (error_browser.count > 1) {
+		xsprintf(disp.line2, PSTR("<%u/%u> "), error_browser.index + 1, error_browser.count);
+	} else {
+		disp.line2[0] = '\0';
+	}
+	strcat_P(disp.line2, error_list[found_index].name);
+}
+
+unsigned char error_browser_func(unsigned char k) {
+	if (k == K_LEFT && error_browser.count > 0) {
+		if (error_browser.index > 0)
+			error_browser.index--;
+		else
+			error_browser.index = error_browser.count - 1;
+		return 1;
+	}
+	if (k == K_RIGHT && error_browser.count > 0) {
+		error_browser.index++;
+		if (error_browser.index >= error_browser.count)
+			error_browser.index = 0;
+		return 1;
+	}
+	/* Long press on UP to reset errors */
+	if (k == (K_UP | K_DOWN)) { /* both up and down pressed together as "confirm" */
+		System.global_error = ERROR_NO;
+		error_browser.index = 0;
+		error_browser.count = 0;
+		return 1;
+	}
+	return 0;
+}
+
 void display_refresh(unsigned char changed) {
 	if (timer_expired(lcd)) {
 		changed = 1;

soft/display.h

@@ -30,4 +30,6 @@ void disp_speed(void);
 void disp_time(void);
 void disp_func_temperature(void);
 void disp_pause_time(void);
+void disp_func_global_error(void);
+unsigned char error_browser_func(unsigned char k);
 

soft/main.c

@@ -259,15 +259,21 @@ void ioinit (void)
 void close_files(unsigned char flush_logs) {
 	UINT bw;
 	if (FLAGS & F_FILEOPEN) {
-		if (f_close(&gps_log))
+		if (f_close(&gps_log)) {
 			System.status = STATUS_FILE_CLOSE_ERROR;
-		if (gpx_close(&gpx_file))
+			System.global_error |= ERROR_FILE_CLOSE;
+		}
+		if (gpx_close(&gpx_file)) {
 			System.status = STATUS_FILE_CLOSE_ERROR;
+			System.global_error |= ERROR_FILE_CLOSE;
+		}
 		if (flush_logs && logbuf.len && !f_write(&system_log, logbuf.buf, logbuf.len, &bw)) {
 			logbuf.len = 0;
 		}
-		if (f_close(&system_log))
+		if (f_close(&system_log)) {
 			System.status = STATUS_FILE_CLOSE_ERROR;
+			System.global_error |= ERROR_FILE_CLOSE;
+		}
 		xputs_P(PSTR("File closed\r\n"));
 		display_event(DISPLAY_EVENT_FILE_CLOSED);
 	}
@@ -400,6 +406,7 @@ int main (void)
 		if (res != FR_OK) {
 			xprintf(PSTR("FS error %u\r\n"), res);
 			System.status = STATUS_DISK_ERROR;
+			System.global_error |= ERROR_DISK;
 			continue;
 		}
 		System.status = STATUS_NO_GPS;
@@ -422,7 +429,14 @@ int main (void)
 		for (;;) { /* main loop */
 			wdt_reset();
 			gettemp();
+
+			/* Check temperature sensor after initialization */
+			if ((FLAGS & F_GPSOK) && !System.temperature_ok) {
+				System.global_error |= ERROR_TEMPERATURE;
+			}
+
 			menu();
+			check_error_and_jump();
 			display_refresh(0);
 			if (no_menu())
 				menu_push(default_menu); /* returned from top-level */
@@ -470,6 +484,7 @@ int main (void)
 				f_write(&gps_log, Line, len-1, &bw);
 				if (bw != len-1) {
 					System.status = STATUS_FILE_WRITE_ERROR;
+					System.global_error |= ERROR_FILE_WRITE;
 					break;
 				}
 				if (System.location_valid == LOC_VALID_NEW) { /* a new point */
@@ -480,6 +495,7 @@ int main (void)
 				if (FLAGS & F_SYNC) {
 					if (f_sync(&gps_log)) {
 						System.status = STATUS_FILE_SYNC_ERROR;
+						System.global_error |= ERROR_FILE_SYNC;
 						break;
 					}
 					FLAGS &= ~F_SYNC;
@@ -510,6 +526,7 @@ int main (void)
 					|| f_write(&gps_log, "\r\n", 2, &bw))					/* Put a blank line as start marker */
 				{
 					System.status = STATUS_FILE_OPEN_ERROR;
+					System.global_error |= ERROR_FILE_OPEN;
 					break;	/* Failed to start logging */
 				}
 
@@ -521,6 +538,7 @@ int main (void)
 				{
 					f_close(&gpx_file);
 					System.status = STATUS_FILE_OPEN_ERROR;
+					System.global_error |= ERROR_FILE_OPEN;
 					break;	/* Failed to start logging */
 				}
 
@@ -533,6 +551,7 @@ int main (void)
 					f_close(&gpx_file);
 					f_close(&gps_log);
 					System.status = STATUS_FILE_OPEN_ERROR;
+					System.global_error |= ERROR_FILE_OPEN;
 					break;	/* Failed to start logging */
 				}
 				wdt_enable(WDTO_4S);

soft/main.h

@@ -102,6 +102,12 @@
 #define ERROR_NO	0
 #define ERROR_I2C	1
 #define ERROR_I2C_TIMEOUT	2
+#define ERROR_TEMPERATURE	4
+#define ERROR_DISK	8
+#define ERROR_FILE_WRITE	16
+#define ERROR_FILE_SYNC	32
+#define ERROR_FILE_CLOSE	64
+#define ERROR_FILE_OPEN	128
 
 /* System.status vals */
 #define STATUS_NO_POWER	0

soft/menu.c

@@ -186,6 +186,11 @@ unsigned char menu(void) {
 				display_changed = pos.func();
 			}
 			break;
+		case MENU_TYPE_FUNCTION_WITH_KEY:
+			if (k) {
+				display_changed = pos.func_key(k);
+			}
+			break;
 	}
 	
 	if (display_line1_as_string) {

soft/menu.h

@@ -4,6 +4,7 @@
 #define MENU_TYPE_SETTING_U8	1
 #define MENU_TYPE_DISPLAY		2
 #define MENU_TYPE_FUNCTION		3
+#define MENU_TYPE_FUNCTION_WITH_KEY	4
 
 #define IS_SETTING(x) (x<3)
 
@@ -37,7 +38,10 @@ struct menu_pos {
 	};
 	unsigned char index;			// index when IS_SETTING()
 	void (* changed)(void);			// what to call on changed value when IS_SETTING()
-	unsigned char (* func)(void);			// what to call on MENU_DISPLAY_TYPE_NAME_FUNCTION; returns true if display refresh is needed
+	union {
+		unsigned char (* func)(void);			// what to call on MENU_TYPE_FUNCTION; returns true if display refresh is needed
+		unsigned char (* func_key)(unsigned char k);	// what to call on MENU_TYPE_FUNCTION_WITH_KEY; returns true if display refresh is needed
+	};
 	unsigned char allow_back;		// left arrow will return to level up
 };
 

soft/working_modes.c

@@ -151,6 +151,12 @@ __flash const struct menu_pos default_menu_list[] = {
 		.display = disp_func_temperature,
 		.func = enter_main_menu,
 	},
+	{
+		.type = MENU_TYPE_FUNCTION_WITH_KEY,
+		.display_type = MENU_DISPLAY_TYPE_FUNCTION,
+		.display = disp_func_global_error,
+		.func_key = error_browser_func,
+	},
 };
 
 __flash const struct menu_struct default_menu = {
@@ -169,3 +175,25 @@ unsigned char enter_main_menu(void) {
 	return 1;
 }
 
+void check_error_and_jump(void) {
+	static unsigned int prev_error = ERROR_NO;
+	struct menu_struct *curr;
+
+	/* Only act if we're in the default menu and error changed */
+	if (__menu_num != 1)
+		return;
+
+	curr = menu_get();
+	if (curr->list != default_menu_list)
+		return;
+
+	/* Check if a new error occurred */
+	if (System.global_error != ERROR_NO && prev_error == ERROR_NO) {
+		/* Jump to last menu item (error display) */
+		curr->ind = curr->num - 1;
+		display_refresh(1);
+	}
+
+	prev_error = System.global_error;
+}
+

soft/working_modes.h

@@ -14,4 +14,5 @@ void key_process(void);
 unsigned char enter_settings(void);
 unsigned char enter_main_menu(void);
 void tracking_pause(unsigned char cmd, unsigned char display);
+void check_error_and_jump(void);