E-G.O. Cache — ESP32 Digital Geocache Logbook (Browser Web Flasher)

AutoMate Vol.1: Low Power Apps · LPA-02 · Age: 16+

A configurable ESP32 digital geocache logbook beacon — a DIY electronic logbook geocachers find in the field, connect to over Wi-Fi, and sign digitally instead of a paper log. First boot launches a setup page: name your cache, set your Wi-Fi, pick your theme color. No code editing.

Buy E-G.O. Cache: whizworks.gumroad.com/l/qtcjj

This repo hosts the browser-based installer for it: buy it on Gumroad, then flash your ESP32, ESP32-S3, or ESP32-C3 board straight from Chrome or Edge — open install.html, enter your license key, click, done. No build tools needed. ESP32-S3 is hardware-verified; classic ESP32 and ESP32-C3 are build-verified only (compiles clean, not yet confirmed on physical hardware) — see manifest.json's per-chip builds.

It exists only to host the files a browser needs to flash a device over USB (ESP Web Tools requires them to be fetchable over HTTP/HTTPS) — it's not an invitation to use the firmware without a purchase. See LICENSE.txt.

Getting started

1. Purchase on Gumroad → instantly receive a license key + the full source code as a zip.
2. Flash via browser: whoishafiz.github.io/E-G.O.-Cache/install.html (Chrome or Edge on desktop) — enter your license key, plug in your ESP32, ESP32-S3, or ESP32-C3 board, click Connect & Install.
3. Power on → connect to the device's Wi-Fi → run the first-boot setup page to name your cache and finish configuration.

Files in this folder

File	Purpose
manifest.json	ESP Web Tools manifest — one builds[] entry per chip family, each a single merged image at offset 0x0
firmware-esp32s3.bin	Merged bootloader+partition-table+app image for ESP32-S3 (hardware-verified)
firmware-esp32.bin	Same, for classic ESP32 (build-verified only)
firmware-esp32c3.bin	Same, for ESP32-C3 (build-verified only)
install.html	Browser flasher page + license-key gate UI
cloudflare-worker.js	CORS relay to Gumroad's license-verify endpoint
LICENSE.txt	Terms — flasher page reusable, .bin files are not
robots.txt	Blocks search-engine indexing of this page

Rebuilding the firmware binaries

Each firmware-<chip>.bin is a single merged image (bootloader + partition table + app, via esptool.py merge_bin) so the manifest only needs one offset-0x0 part per chip, sidestepping the bootloader-offset difference between chip families (0x0 for S3/C3, 0x1000 for classic ESP32). To rebuild all three after a firmware change:

idf.py set-target <esp32s3|esp32|esp32c3>
idf.py build
python -m esptool --chip <chip> merge_bin -o flasher/firmware-<chip>.bin \
  --flash_mode dio --flash_freq <from build/flash_args> --flash_size 4MB \
  <0x0 or 0x1000 — see build/flash_args> build/bootloader/bootloader.bin \
  0x8000 build/partition_table/partition-table.bin \
  0x10000 build/geocache.bin

Repeat per target, then idf.py set-target esp32s3 && idf.py build again to restore the primary dev target before committing. Read --flash_mode/ --flash_freq/the bootloader offset from the freshly generated build/flash_args each time rather than assuming — they differ by target.