feat(lora+gps): Add components for gps, sx126x lora radio. Add preliminary meshtastic component (ai-generated), and update bsps to start testing

[finger563]

Description

Adds LoRa + GPS support to espp, along with a radio-agnostic Meshtastic
node, and wires all three into the T-Deck and M5Stack Cardputer BSPs.

New components

• sx126x — espp::Sx126x driver for Semtech SX1261 / SX1262 / LLCC68
  LoRa radios. Built on espp::BasePeripheral<uint8_t, false>; the caller
  supplies a write_then_read that holds chip-select across the write and
  read phases (one full-duplex SPI transfer), since SX126x commands return
  their status/data in the same CS assertion. LoRa modulation with explicit
  header, configurable frequency / SF / BW / CR / preamble / CRC / sync word,
  TCXO and DC-DC/LDO options, and DIO1 IRQ servicing.
• gps — espp::Gps (UART NMEA reader task) plus a platform-independent
  espp::NmeaParser (RMC/GGA) and an espp::GpsFix value type with a
  user-supplied on-fix callback.
• meshtastic — espp::MeshtasticNode, radio-agnostic (you provide a
  transmit function and feed it received frames). Implements over-the-air
  interop on the public default channel: 16-byte little-endian packet header,
  AES-CTR payload encryption with the default PSK, djb2 frequency-slot + XOR
  channel hashing, a small hand-written protobuf codec for Text / NodeInfo /
  Position, packet de-duplication, and optional managed-flood rebroadcast.
  The README carries a clean-room / licensing note (Meshtastic firmware and
  protobufs are GPL-3; this is an independent MIT implementation of the
  wire format).

BSP integration — both boards gain initialize_lora(radio_config) /
lora() and initialize_gps(...) / gps():

• T-Deck: SX1262 (HPD16A module, 1.8 V TCXO on DIO3, DIO2 RF switch) on
  the shared LCD/SD SPI bus. GPS (T-Deck Plus, u-blox MIA-M10Q) over UART.
• M5Stack Cardputer-Adv + LoRa/GPS Cap: SX1262 (Stamp LoRa-1262 Mini
  module, 3.0 V TCXO on DIO3, LDO regulator) on the shared microSD SPI bus,
  with the Cap's PI4IOE5V6408 IO expander driving the RF switch / GPS LNA;
  ATGM336H GPS over UART.

Examples

• Standalone sx126x, gps, and meshtastic examples (the meshtastic
  example has a Kconfig board + region selector and runs a full node).
• The T-Deck GUI example gains a LoRa tab (status, text entry + Send,
  scrolling RX/TX log with RSSI/SNR).
• The Cardputer GUI example is reorganized into a 6-tab layout
  (Text / LoRa / IMU / GPS / Sys / Help) with keyboard navigation, and now
  brings up GPS when the Cap is present.

Docs / CI — per-component READMEs, a new doc/en/wireless/ docs section
(index + sx126x + gps + meshtastic, each with an example page), Doxyfile
inputs, and build.yml / upload_components.yml matrix entries for the three
new examples.

Motivation and Context

espp had no LoRa or GPS support and no path to interoperate with the
Meshtastic ecosystem. This adds reusable, radio-/board-agnostic building
blocks (a general SX126x driver, an NMEA GPS reader, and a Meshtastic wire
codec) and demonstrates them end-to-end on two popular ESP32-S3 dev boards,
so espp users can build LoRa messaging / mesh / tracker applications.

How has this been tested?

so espp users can build LoRa messaging / mesh / tracker applications.

How has this been tested?

• Hardware: T-Deck ↔ M5Stack Cardputer-Adv (+ LoRa/GPS Cap) messaging over
  a raw private LoRa link (US LongFast modulation, private sync word 0x12),
  confirmed bidirectional on real devices using the GUI examples' LoRa tabs.
  GPS fixes displayed on both boards. TCXO voltage / regulator settings for
  each module were validated against the vendors' RadioLib configs after an
  initial dead-oscillator symptom on the Cardputer module.
• Builds: all new/changed examples build clean for esp32s3 with
  ESP-IDF v5.5.2 — sx126x, gps, and meshtastic examples (the latter for
  both the T-Deck and Cardputer-Adv Kconfig targets), plus the updated T-Deck
  and Cardputer GUI examples.
• Static analysis: cppcheck (--enable=all, the repo's CI config) clean
  on the changed files.
• Not yet tested: the Meshtastic component has not been validated
  over-the-air against a stock Meshtastic device/phone — all hardware testing
  so far used the raw-LoRa path, which shares the SX126x driver but not the
  Meshtastic framing/crypto. This is the main follow-up before relying on
  mesh interop.

Screenshots (if appropriate, e.g. schematic, board, console logs, lab pictures):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update
• Hardware (schematic, board, system design) change
• Software change

Checklist:

• My change requires a change to the documentation.
• I have added / updated the documentation related to this change via either README or WIKI

Software

• I have added tests to cover my changes.
• I have updated the .github/workflows/build.yml file to add my new test to the automated cloud build github action.
• All new and existing tests passed.
• My code follows the code style of this project.

[github-actions]

✅Static analysis result - no issues found! ✅

[Copilot]

Pull request overview

Adds a new “wireless” documentation section and introduces new gps, sx126x (LoRa radio), and preliminary meshtastic components, then wires LoRa/GPS support into the LilyGo T-Deck and M5Stack Cardputer-Adv BSPs and examples so they can be built/tested in CI.

Changes:

• Add new components: gps (UART NMEA GNSS), sx126x (SX1261/2/LLCC68 LoRa driver), meshtastic (radio-agnostic Meshtastic-compatible node + example).
• Update BSPs/examples (t-deck, m5stack-cardputer) to initialize and demonstrate LoRa + GPS (plus shared-bus handling on the Cardputer Cap).
• Update docs (new doc/en/wireless/*) and CI/component publishing lists to include the new components and examples.

Reviewed changes

Copilot reviewed 68 out of 68 changed files in this pull request and generated 9 comments.

Show a summary per file

File	Description
doc/en/wireless/index.rst	Introduces the “Wireless & Radio APIs” doc section and links new wireless component pages.
doc/en/wireless/sx126x.rst	Adds SX126x component documentation entry and API include hooks.
doc/en/wireless/gps.rst	Adds GPS component documentation entry and API include hooks.
doc/en/wireless/meshtastic.rst	Adds Meshtastic component documentation entry and API include hooks.
doc/en/index.rst	Adds the wireless docs section to the top-level docs index.
doc/Doxyfile	Adds new components’ headers/examples to Doxygen inputs/example paths.
components/sx126x/CMakeLists.txt	Registers the sx126x component build.
components/sx126x/include/sx126x.hpp	Defines the public SX126x driver API/types/config.
components/sx126x/src/sx126x.cpp	Implements the SX126x driver (SPI command layer + LoRa modem support).
components/sx126x/README.md	Adds SX126x component overview and feature list.
components/sx126x/idf_component.yml	Adds SX126x component manager metadata (deps/tags/docs link).
components/sx126x/example/CMakeLists.txt	Adds SX126x example project configuration.
components/sx126x/example/sdkconfig.defaults	Adds SX126x example default sdkconfig.
components/sx126x/example/README.md	Adds SX126x example usage documentation.
components/sx126x/example/main/CMakeLists.txt	Registers the SX126x example “main” component.
components/sx126x/example/main/Kconfig.projbuild	Adds SX126x example menuconfig options (hardware/pins/frequency/etc.).
components/sx126x/example/main/sx126x_example.cpp	Adds SX126x example app (bring-up + RX + periodic TX ping).
components/gps/CMakeLists.txt	Registers the gps component build.
components/gps/include/gps.hpp	Defines the UART-attached GPS driver public API.
components/gps/include/nmea_parser.hpp	Defines the platform-independent NMEA parser API.
components/gps/include/gps_fix.hpp	Defines the parsed fix struct and timestamp conversion helper.
components/gps/src/gps.cpp	Implements the UART driver + background read/parsing task.
components/gps/src/nmea_parser.cpp	Implements NMEA parsing/checksum and fix extraction.
components/gps/README.md	Adds GPS component overview and capabilities.
components/gps/idf_component.yml	Adds GPS component manager metadata (deps/tags/docs link).
components/gps/example/CMakeLists.txt	Adds GPS example project configuration.
components/gps/example/sdkconfig.defaults	Adds GPS example default sdkconfig.
components/gps/example/README.md	Adds GPS example usage documentation.
components/gps/example/main/CMakeLists.txt	Registers the GPS example “main” component.
components/gps/example/main/Kconfig.projbuild	Adds GPS example menuconfig options (hardware/pins/baud).
components/gps/example/main/gps_example.cpp	Adds GPS example app (print fixes).
components/meshtastic/CMakeLists.txt	Registers the meshtastic component build.
components/meshtastic/include/meshtastic.hpp	Defines MeshtasticNode public API/config/callbacks.
components/meshtastic/include/meshtastic_types.hpp	Adds protocol constants and message structs.
components/meshtastic/include/meshtastic_protocol.hpp	Declares channel hashing/modem config/header pack/unpack helpers.
components/meshtastic/include/meshtastic_crypto.hpp	Declares PSK expansion and AES-CTR payload crypt helpers.
components/meshtastic/include/meshtastic_protobuf.hpp	Declares minimal protobuf encode/decode helpers for used messages.
components/meshtastic/src/meshtastic.cpp	Implements node behavior (send/receive/dedup/rebroadcast).
components/meshtastic/src/meshtastic_protocol.cpp	Implements region/preset-based modem config + header pack/unpack + hashes.
components/meshtastic/src/meshtastic_crypto.cpp	Implements PSK expansion and AES-CTR crypt via mbedtls.
components/meshtastic/src/meshtastic_protobuf.cpp	Implements minimal protobuf wire-format encode/decode for required messages.
components/meshtastic/README.md	Adds Meshtastic component overview/scope/licensing notes.
components/meshtastic/idf_component.yml	Adds Meshtastic component manager metadata (deps/tags/docs link).
components/meshtastic/example/CMakeLists.txt	Adds Meshtastic example project configuration.
components/meshtastic/example/sdkconfig.defaults	Adds Meshtastic example default sdkconfig.
components/meshtastic/example/README.md	Adds Meshtastic example usage documentation.
components/meshtastic/example/main/CMakeLists.txt	Registers the Meshtastic example “main” component.
components/meshtastic/example/main/Kconfig.projbuild	Adds Meshtastic example menuconfig options (hardware/region/intervals/etc.).
components/meshtastic/example/main/meshtastic_example.cpp	Adds Meshtastic node example using BSP-provided SX1262 radio.
components/t-deck/CMakeLists.txt	Adds gps/sx126x to T-Deck component requirements.
components/t-deck/idf_component.yml	Adds gps/sx126x dependencies to the T-Deck component manifest.
components/t-deck/include/t-deck.hpp	Adds LoRa + GPS APIs/pins/state to the T-Deck BSP.
components/t-deck/src/lora.cpp	Implements T-Deck LoRa + GPS initialization.
components/t-deck/example/README.md	Updates T-Deck example docs to include LoRa demo behavior.
components/t-deck/example/main/t_deck_example.cpp	Adds LoRa tab/demo wiring and non-blocking TX dispatch via main loop.
components/t-deck/example/main/gui.hpp	Extends T-Deck example GUI API to support a LoRa tab and logging.
components/t-deck/example/main/gui.cpp	Implements the new LoRa tab UI and thread-safe message/status updates.
components/m5stack-cardputer/CMakeLists.txt	Adds gps/sx126x to Cardputer component requirements.
components/m5stack-cardputer/idf_component.yml	Adds gps/sx126x dependencies to the Cardputer component manifest.
components/m5stack-cardputer/include/m5stack-cardputer.hpp	Adds LoRa+GPS Cap APIs/pins/state and new helper methods.
components/m5stack-cardputer/src/lora_gps_cap.cpp	Implements LoRa+GPS Cap SPI-bus bring-up and LoRa/GPS initialization.
components/m5stack-cardputer/src/sdcard.cpp	Adjusts SD init to reuse the shared expansion SPI bus when LoRa is present.
components/m5stack-cardputer/example/README.md	Updates Cardputer example docs for new tabbed UI + LoRa/GPS features.
components/m5stack-cardputer/example/main/m5stack_cardputer_example.cpp	Wires LoRa+GPS demos into the example and updates tab/shortcut behavior.
components/m5stack-cardputer/example/main/gui.hpp	Refactors Cardputer GUI into tabbed layout with LoRa/GPS/Sys tabs.
components/m5stack-cardputer/example/main/gui.cpp	Implements tabbed UI, LoRa log/status rendering, and new per-tab helpers.
.github/workflows/build.yml	Adds gps/meshtastic/sx126x examples to CI build matrix.
.github/workflows/upload_components.yml	Adds gps/meshtastic/sx126x to component upload list.

[Copilot]

Pull request overview

Copilot reviewed 71 out of 71 changed files in this pull request and generated 4 comments.

[Copilot]

Pull request overview

Copilot reviewed 71 out of 71 changed files in this pull request and generated 1 comment.

[Copilot]

Pull request overview

Copilot reviewed 71 out of 71 changed files in this pull request and generated 1 comment.

Comments suppressed due to low confidence (3)

components/t-deck/example/main/t_deck_example.cpp:1

• std::transform is used but <algorithm> is not included in this file, which can cause compilation failures depending on toolchain/headers. Add #include <algorithm> alongside the other standard includes.
  components/t-deck/example/main/t_deck_example.cpp:1
• std::transform is used but <algorithm> is not included in this file, which can cause compilation failures depending on toolchain/headers. Add #include <algorithm> alongside the other standard includes.
  components/meshtastic/src/meshtastic_protobuf.cpp:1
• pos + length > size can overflow when length is a large varint (and then incorrectly pass the bounds check), and (size_t)length truncation can produce a span smaller than intended. Use an overflow-safe bounds check (e.g., length > (size - pos) after validating length <= SIZE_MAX) before creating the span and advancing pos.

[Copilot]

Pull request overview

Copilot reviewed 71 out of 71 changed files in this pull request and generated no new comments.

Comments suppressed due to low confidence (4)

components/t-deck/example/main/t_deck_example.cpp:1

• std::transform is used later in this file (in printable()), but <algorithm> is not included in the shown includes. This is a compile error on standard toolchains; add #include <algorithm>.
  components/sx126x/src/sx126x.cpp:1
• receiving_ is set to false in start_transmit(), so this TX_DONE path will never restart RX even if the radio was in continuous receive before TX (for non-blocking start_transmit() usage). If the intended behavior is “return to RX if we were receiving before TX”, store that prior state (e.g., return_to_rx_after_tx_) in start_transmit() and consult it here; otherwise, update/remove the misleading comment.
  components/meshtastic/src/meshtastic_protobuf.cpp:1
• The decode paths parse fields without validating that wire matches the expected protobuf wire type for that field (e.g., portnum should be VARINT, payload should be LENGTH). Because this processes untrusted over-the-air frames, add wire-type checks per field and skip(wire) (or return nullopt) on mismatch to avoid mis-decoding random/corrupted bytes into plausible-looking messages.
  components/meshtastic/src/meshtastic.cpp:1
• On invalid PSK length, expand_psk() returns an empty key and the node continues operating unencrypted (only logging an error). That’s a dangerous failure mode because it can silently downgrade confidentiality if logs are missed. Consider making this a hard failure (e.g., set an internal psk_valid_ flag and have send_*()/handle_frame() refuse to operate when invalid), or provide an explicit allow_unencrypted_fallback config to require a conscious opt-in.