robot_serial_display

Simple LVGL dashboard demo for a robot (ROVI), targeting the 3.5" 320×480 ESP32‑S3 Touch LCD.

What you get

• Grid layout (configured in data/config.json, default is 2×3 for 320×480)
  • Voltage arc gauge (multi‑stage coloring)
  • CPU arc gauge
  • Pipeline Hz list (spans 2 tiles via repeated tile id)
  • Shutdown / Restart buttons (serial callbacks)
• Fail‑safe display: if a value is older than ui.stale_timeout_ms it shows --
• Splash screen (BMP) loaded from internal flash FS (FFat) before showing the dashboard

Local library

This sample uses two local PlatformIO libraries:

• lib/WsLcd35S3Hal/ (board/HAL)
  • Brings up Arduino_GFX + touch + LVGL display/input
  • Mounts internal FFat and registers it as LVGL drive F:
• lib/LiveDashboard/ (UI)
  • Loads /config.json from internal FFat
  • Builds the tile grid + widgets from config
  • Shows splash from internal FFat (e.g. F:/rovi.bmp)

src/main.cpp stays minimal:

• Registers callbacks for shutdown / restart
• Optional JSONL demo replay (from data/test.jsonl) enabled via init options
• Serial event ingestion (one JSON line per \n)

Internal config (FFat)

• data/config.json and data/rovi.bmp are built into the internal flash FATFS partition (ffat in partitions/partitions_16MB_3MBapp_9_9MB_fatfs.csv).
• /config.json is required: if it’s missing or invalid the firmware prints a fatal message and shows a “CONFIG ERROR” screen.

Upload the filesystem image:

• pio run -e esp32-s3-touch-lcd-35 -t uploadfs

Updating values

In src/main.cpp the demo uses:

• g_dashboard.publishGauge("voltage", voltage_x10, "12.1V")
• g_dashboard.publishGauge("cpu", cpu_percent, "37%")
• g_dashboard.tick() (called from loop() to enforce stale/-- behavior)

Demo input (JSONL + Serial)

The sample includes a simple “event replay” demo:

• data/test.jsonl is uploaded to internal FFat and can be replayed once per second (loops at EOF).
• You can paste the same JSON lines into the serial monitor; the line is applied when a full newline is received.
• Toggle JSONL replay via ROVI_ENABLE_JSONL_DEMO_REPLAY in src/main.cpp.
• If JSONL replay is enabled and /test.jsonl is missing, the app fails hard and shows an error screen.

Line format:

• Single update: {"id":"voltage","value":121,"text":"12.1V"}
• Multiple updates in one line: [{"id":"voltage","value":121,"text":"12.1V"},{"id":"cpu","value":37,"text":"37%"}]
• Limits: max line length 1024 chars, max 5 events per line.

Build (PlatformIO)

From the project folder:

• pio run -e esp32-s3-touch-lcd-35
• pio run -e esp32-s3-touch-lcd-35 -t upload