System Monitor (sysmon)

The System Monitor module provides real-time monitoring of system performance metrics directly on your display. It supports both performance monitoring (CPU usage and FPS) and memory monitoring (us...

The System Monitor module provides real-time monitoring of system performance metrics directly on your display. It supports both performance monitoring (CPU usage and FPS) and memory monitoring (used memory and fragmentation).

Dependencies

• Requires LV_USE_LABEL = 1 in lv_conf.h
• Requires LV_USE_OBSERVER = 1 in lv_conf.h
• Requires LV_USE_SYSMON = 1 in lv_conf.h

Usage

Configuration

Enable in lv_conf.h:

/* Main sysmon enable */
#define LV_USE_SYSMON 1

/* Performance monitor (CPU% and FPS) */
#define LV_USE_PERF_MONITOR 1

/* Memory monitor (used + fragmentation) */
#define LV_USE_MEM_MONITOR 1

/* Optional: refresh period in ms */
#define LV_SYSMON_REFR_PERIOD_DEF 300

/* Optional: log to console instead of screen */
#define LV_USE_PERF_MONITOR_LOG_MODE 0

Creating Monitors

/* Create generic monitor */
lv_obj_t * sysmon = lv_sysmon_create(lv_display_get_default());

/* Create performance monitor */
lv_sysmon_show_performance(NULL);  /* NULL = default display */

/* Create memory monitor */
lv_sysmon_show_memory(NULL);

Performance Monitor

Tracks:

• FPS (Frames Per Second)
• CPU usage (%)
• Render time (ms)
• Flush time (ms)
• Self CPU usage (%) if enabled

Display format:

32 FPS, 45% CPU
8 ms

Where:

• Line 1: FPS, Total CPU%
• Line 2: Total time (Render | Flush)

Pause and Resume

lv_sysmon_performance_pause(disp) pauses the perf monitor.

lv_sysmon_performance_resume(disp) resumes the perf monitor.

Memory Monitor

Displays:

• Current memory usage (kB and %)
• Peak memory usage (kB)
• Fragmentation (%)

Display format:

24.8 kB (76%)
32.4 kB max, 18% frag.

Positioning

Configure positions in lv_conf.h:

/* Top-right corner */
#define LV_USE_PERF_MONITOR_POS LV_ALIGN_TOP_RIGHT

/* Bottom-right corner */
#define LV_USE_MEM_MONITOR_POS LV_ALIGN_BOTTOM_RIGHT

Implementation Details

Initialization

Maintains:

• Global memory monitor (sysmon_mem)
• Per-display performance structures

Performance Measurement

Event-based collection:

Timers

• Performance: perf_update_timer_cb
• Memory: mem_update_timer_cb
• Default period: 300ms (LV_SYSMON_REFR_PERIOD_DEF)