---
name: tactility-firmware-development
description: Use when merging current Tactility firmware, preserving local ES3C28P/ES3C35P customizations, building/flashing ESP32 firmware, or validating external apps against it.
---

# Tactility firmware development

## Scope and success criteria

Use this skill for firmware upgrades, especially when upstream changes the app
loader, dashboard API, SDK export, or device model. Before editing, record the
active branch, `git status --short`, selected `Devices/<id>`, serial port, and
the expected device identity. Preserve user work and local board
customizations; do not reset or overwrite a dirty tree.

Success is not merely a successful flash: the board must boot, mount storage,
return `/api/sysinfo`, expose required internal apps, and accept an external
app rebuilt against this exact firmware.

## Upgrade and customization audit

1. Fetch and compare the intended upstream branch before merging. Treat
   `upstream/main` as distinct from experimental release/IDF branches unless
   the task explicitly asks for one of those branches.
2. Merge without discarding local work (for example, `git merge --autostash
   upstream/main` after inspecting status). Resolve conflicts by preserving
   required ES3C28P and ES3C35P device definitions, partition selection,
   display/font customizations, and product features.
3. Compare the pre-upgrade customization commit against the resulting worktree.
   Check new app registrations, CMake/source inclusion, settings pages,
   web-server endpoints, and board-specific `sdkconfig` entries—not just files
   that happen to conflict.
4. Commit the resulting firmware customization as a focused, reviewable
   commit after `git diff --check`.

## Multi-binary external-app compatibility

Upstream app packaging changed to `bin/<platform>/<binary>.elf`. The old
`elf/<platform>.elf` archive layout produces a loader `Not executable` error.

- Manifest v0.2: `bin/esp32s3/app.elf`
- Manifest v0.3: `bin/esp32s3/<app.0.binary>.elf`

When this change arrives, update the companion app tool and rebuild every app
from a fresh SDK exported from this firmware. Do not attempt to repair a
packaged ELF on the SD card: its layout and ABI must both be regenerated.

## Build and flash

Use the installed IDF 5.5 environment; host virtual environments can corrupt
both Python dependencies and IDF tooling:

```zsh
unset VIRTUAL_ENV PYTHONPATH PYTHONHOME
export IDF_PYTHON_ENV_PATH=/Users/adolforeyna/.espressif/python_env/idf5.5_py3.9_env
source /Users/adolforeyna/esp/esp-idf/export.sh

# Select/check the intended board before this step.
python device.py <device-id>
idf.py build
idf.py -p /dev/cu.usbmodemXXXX flash
```

`Tactility/CMakeLists.txt` uses a non-configure-dependent source glob. After
adding a new `.c`/`.cpp` file, run `idf.py reconfigure build`; otherwise a
linker error for a newly referenced symbol may only mean CMake has not
discovered the source file yet.

## Boot and feature acceptance

Capture serial at 115200 after flash or reset. Confirm the board name, SD-card
mount, HTTP-server start, Wi-Fi address, and any feature-specific startup logs.
Then query the resolved device:

```zsh
curl -fsS http://<ip>/api/sysinfo
curl -fsS http://<ip>/api/apps
```

For MCP settings, verify the `McpSettings` internal app appears in `/api/apps`.
When enabled, verify MCP stream startup logs. For a feature restored from an
older customization, validate its registration path and persisted settings,
not only its source files.

## External-app acceptance gate

Use the companion app skill's exact-firmware wrapper:

```zsh
cd /path/to/tactility_apps
scripts/build_current_firmware_app.sh Apps/MyApp --firmware /path/to/tactility
```

Inspect the resulting tar member path, install through port-80 dashboard API,
launch it, and read serial. Required evidence is the loader's `Loading
.../bin/...`, an ELF entry address, `Task started`, and app-specific startup
logs. HTTP 200 or a package simply appearing in `/api/apps` is insufficient.