Scuba Tank Dive Tracker (Vision Master E290)

This project runs on a Heltec Vision Master E290 and displays dive stats on e-paper.

It supports:

• Normal low-power operation with deep sleep
• Orientation-based display layout
• Magnet/reed-switch wake
• OTA firmware updates
• Optional internet auto-update from GitHub release binaries
• Daily data refresh from a JSON endpoint
• Auto firmware version from Git (git describe --tags --always --dirty)

What It Displays

The firmware fetches JSON from JSON_URL defined in src/secrets.h.

Expected fields:

• totalDives
• totalMinutesUnderwater
• deepestDive
• daysUntil
• nextDive

Wake + Sleep Behavior

• Device wakes from:
  • Reed switch (WAKE_PIN LOW)
  • 24-hour timer wake
• After handling wake logic, it returns to deep sleep.

Data Refresh Behavior

• Forced refresh (?refresh=1) happens only when:
  • The 24-hour timer wake fires
  • OTA mode is entered
• Other wake events show cached values from RTC memory.

Magnet / Orientation Behavior

• Reed switch LOW opens a short orientation check window.
• OTA mode is entered when rotation matches OTA_ROTATION (currently 270 in code trigger logic).
• Side orientations are rendered at 90-degree display orientation to avoid showing a 270-degree-rendered screen.

Relevant constants in src/DiveInfo.ino:

• OTA_ROTATION
• OTA_WINDOW_MS
• WAKE_PIN

OTA Behavior

• OTA mode screen shows:
  • Logo + battery
  • Current device IP
• OTA listens for OTA_WINDOW_MS (currently 60s).
• If no OTA upload occurs, firmware reboots.

Internet OTA (Optional)

• If INTERNET_OTA_MANIFEST_URL is set in src/secrets.h, firmware checks for updates:
  • During daily timer wake (INTERNET_OTA_CHECK_ON_TIMER_WAKE = 1)
  • When OTA mode is entered with the magnet
• If manifest version differs from current firmware version, the device downloads and applies bin_url.
• Updates are skipped when battery percent is below INTERNET_OTA_MIN_BATTERY_PERCENT.

Manifest JSON example:

{
  "version": "v1.6.0",
  "bin_url": "https://github.com/<user>/<repo>/releases/download/v1.6.0/firmware.bin"
}

Build and Upload (PlatformIO)

platformio.ini is configured with:

• vision_master_e290 (default): OTA upload (espota)
• vision_master_e290_usb: emergency USB upload (esptool, COM9)

Commands:

# Default (OTA)
platformio run -e vision_master_e290 -t upload

# Emergency USB
platformio run -e vision_master_e290_usb -t upload

First-Time Configuration Checklist

Firmware secrets/config:

• Copy src/secrets.example.h to src/secrets.h
• Set your own:
  • wifiList
  • JSON_URL
  • OTA_HOSTNAME
  • OTA_PASSWORD (set non-empty for protection)
  • INTERNET_OTA_MANIFEST_URL (optional)
  • INTERNET_OTA_MIN_BATTERY_PERCENT (optional)
  • INTERNET_OTA_CHECK_ON_TIMER_WAKE (optional)

Runtime settings in code (src/DiveInfo.ino):

• OTA_ROTATION if you want a different trigger orientation

Edit platformio.ini:

• upload_port under env:vision_master_e290 to current OTA IP shown on the device
• upload_port under env:vision_master_e290_usb if COM port changes

Worker secrets/config (src/worker.js):

• Set Cloudflare Worker env vars:
  • ICS_URL
  • DIVEL0GS_USER
  • DIVEL0GS_PASS

Notes

• src/worker.js is included in this repo as a Cloudflare Worker source for generating the JSON payload.
• OTA upload requires the board to be on the OTA screen and reachable on the same network.
• src/secrets.h is intentionally ignored by Git so personal Wi-Fi and endpoint values are not committed.
• Firmware version shown on screen is injected at build time from Git via scripts/git_version.py.