M5Stack Tab5 GPS Handheld

A full handheld GPS navigation device built on the M5Stack Tab5 (ESP32-P4) — offline maps, waypoints, live navigation, and trip logging, running entirely on the device with no phone or network connection required.

Modeled loosely on classic dedicated handheld GPS units (think Garmin/Magellan): a real dashboard, a real map you can pan and zoom offline, and a nav screen that gets you to a point you typed or one you saved earlier.

Features

• Home dashboard — live position, speed, heading (compass), altitude, satellite count, GPS accuracy estimate, a trip odometer (distance/moving time/avg+max speed/elevation gain, gated so parked GPS jitter doesn't inflate it), and a real battery gauge.
• Offline map — native, PPA-hardware-accelerated tile renderer (not LVGL) with pan/zoom/drag, tiles served from a microSD card, GPS-follow mode, and a live "you are here" marker.
• Navigation — type coordinates (three formats: DD MM.MMMM, DD.DDDDDD, DD MM SS, with live validation) or pick a saved waypoint, then get live bearing, relative-heading arrow, distance, ETA, closure rate (VMG), and cross-track error to the destination.
• Waypoints — mark your current position, or save a typed coordinate, with a scrollable saved list, tap-to-navigate, and delete-with-confirm. Persisted in a dedicated flash partition.
• Telemetry — per-satellite/per-constellation signal view (bar chart and polar sky view), DOP/fix-type, vertical speed, and position in all three coordinate formats.
• Settings — distance/speed units (mi/mph vs km/kmh), elevation units (ft vs m), coordinate format, 12/24-hour time, display brightness, keep-screen-on, and read-only GPS module info (constellations in view, update rate).
• Trip and raw-track logging — every NMEA sentence is logged to the SD card (append-only across boots, fsync'd per line so an abrupt power loss doesn't lose data), and the Home dashboard's trip totals now persist across a reboot too.
• Real US Central local time (DST-aware) derived from the GPS's own UTC time, no RTC or network needed.

Hardware

• M5Stack Tab5 — ESP32-P4, MIPI-DSI touch panel, USB-Serial-JTAG.
• M5Stack GPS Module v2.1 (AT6668 chipset) on the Tab5's M5-Bus connector, UART @ 115200 8N1.
• microSD card, for offline map tiles and GPS logging.
• Optional: an INA226-based battery gauge on the Tab5's onboard I2C bus (NP-F550-style 2S Li-ion pack).

Building

Requires ESP-IDF v6.0.1, targeting esp32p4.

# after sourcing/activating your ESP-IDF v6.0.1 environment
idf.py build
idf.py -p <PORT> flash

This project targets the Tab5 exclusively — no board-selection variable needed.

Repository layout

• main/ — application source: GPS/NMEA parsing, the LVGL UI (dashboard/map-handoff/nav/telemetry/settings), the native map renderer, and persistence (settings, waypoints, trip totals).
• components/esp_lcd_st7123/ — vendored LCD panel driver.
• tools/ — development scripts:
  • pull_snapshot.py — pull a live screenshot of any LVGL screen over USB, optionally switching tabs first.
  • fetch_tiles.py / arcgis_bundle_to_sd.py — build the offline map tile dataset for the SD card.
  • sdmount.sh / eject.sh / send_to_sd.py / recv_from_sd.py — SD-card transfer workflows.
• partitions.csv — custom dual-OTA-slot partition table, with dedicated NVS partitions for settings, waypoints, and a raw screen-capture scratch region.

License

Apache License 2.0 — see LICENSE.