refactor: drop Heltec V3, enforce standard toolchain, remove dead code

Heltec V3 (ESP32-S3) requires the espup Xtensa toolchain fork, which
violates the standard-toolchain-only principle. Removed until upstream
Rust supports Xtensa targets via stock rustup.

Also removes all #[allow(dead_code)] band-aids — unused items are
deleted rather than suppressed. DESIGN.md updated with standard
toolchain principle (#10) and peripheral model (input/telemetry slots).

Cargo.lock

@@ -14,12 +14,6 @@ dependencies = [
  "zerocopy",
 ]
 
-[[package]]
-name = "anyhow"
-version = "1.0.102"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7f202df86484c868dbad7eaa557ef785d5c66295e41b460ef922eca0723b842c"
-
 [[package]]
 name = "autocfg"
 version = "1.5.0"
@@ -41,21 +35,6 @@ dependencies = [
  "rustc_version",
 ]
 
-[[package]]
-name = "bare-metal"
-version = "1.0.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f8fe8f5a8a398345e52358e18ff07cc17a568fbca5c6f73873d3a62056309603"
-
-[[package]]
-name = "basic-toml"
-version = "0.1.10"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ba62675e8242a4c4e806d12f11d136e626e6c8361d6b829310732241652a178a"
-dependencies = [
- "serde",
-]
-
 [[package]]
 name = "bitfield"
 version = "0.13.2"
@@ -68,12 +47,6 @@ version = "0.14.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2d7e60934ceec538daadb9d8432424ed043a904d8e0243f3c6446bce549a46ac"
 
-[[package]]
-name = "bitfield"
-version = "0.17.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f798d2d157e547aa99aab0967df39edd0b70307312b6f8bd2848e6abe40896e0"
-
 [[package]]
 name = "bitflags"
 version = "1.3.2"
@@ -104,15 +77,6 @@ version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
 
-[[package]]
-name = "chrono"
-version = "0.4.44"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c673075a2e0e5f4a1dde27ce9dee1ea4558c7ffe648f576438a20ca1d2acc4b0"
-dependencies = [
- "num-traits",
-]
-
 [[package]]
 name = "cobs"
 version = "0.3.0"
@@ -128,7 +92,7 @@ version = "0.7.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8ec610d8f49840a5b376c69663b6369e71f4b34484b9b2eb29fb918d92516cb9"
 dependencies = [
- "bare-metal 0.2.5",
+ "bare-metal",
  "bitfield 0.13.2",
  "embedded-hal 0.2.7",
  "volatile-register",
@@ -172,18 +136,8 @@ version = "0.20.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fc7f46116c46ff9ab3eb1597a45688b6715c6e628b5c133e288e709a29bcb4ee"
 dependencies = [
- "darling_core 0.20.11",
+ "darling_core",
- "darling_macro 0.20.11",
+ "darling_macro",
-]
-
-[[package]]
-name = "darling"
-version = "0.21.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9cdf337090841a411e2a7f3deb9187445851f91b309c0c0a29e05f74a00a48c0"
-dependencies = [
- "darling_core 0.21.3",
- "darling_macro 0.21.3",
 ]
 
 [[package]]
@@ -200,37 +154,13 @@ dependencies = [
  "syn 2.0.117",
 ]
 
-[[package]]
-name = "darling_core"
-version = "0.21.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1247195ecd7e3c85f83c8d2a366e4210d588e802133e1e355180a9870b517ea4"
-dependencies = [
- "fnv",
- "ident_case",
- "proc-macro2",
- "quote",
- "syn 2.0.117",
-]
-
 [[package]]
 name = "darling_macro"
 version = "0.20.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fc34b93ccb385b40dc71c6fceac4b2ad23662c7eeb248cf10d529b7e055b6ead"
 dependencies = [
- "darling_core 0.20.11",
+ "darling_core",
- "quote",
- "syn 2.0.117",
-]
-
-[[package]]
-name = "darling_macro"
-version = "0.21.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d38308df82d1080de0afee5d069fa14b0326a88c14f15c5ccda35b4a6c414c81"
-dependencies = [
- "darling_core 0.21.3",
  "quote",
  "syn 2.0.117",
 ]
@@ -276,24 +206,13 @@ dependencies = [
  "thiserror",
 ]
 
-[[package]]
-name = "delegate"
-version = "0.13.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "780eb241654bf097afb00fc5f054a09b687dad862e485fdcf8399bb056565370"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn 2.0.117",
-]
-
 [[package]]
 name = "document-features"
 version = "0.2.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d4b8a88685455ed29a21542a33abd9cb6510b6b129abadabdcef0f4c55bc8f61"
 dependencies = [
- "litrs 1.0.0",
+ "litrs",
 ]
 
 [[package]]
@@ -332,7 +251,7 @@ version = "0.6.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3577b1e9446f61381179a330fc5324b01d511624c55f25e3c66c9e3c626dbecf"
 dependencies = [
- "darling 0.20.11",
+ "darling",
  "proc-macro2",
  "quote",
  "syn 2.0.117",
@@ -414,19 +333,6 @@ dependencies = [
  "rand_core",
 ]
 
-[[package]]
-name = "embassy-sync"
-version = "0.5.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dd938f25c0798db4280fcd8026bf4c2f48789aebf8f77b6e5cf8a7693ba114ec"
-dependencies = [
- "cfg-if",
- "critical-section",
- "embedded-io-async",
- "futures-util",
- "heapless",
-]
-
 [[package]]
 name = "embassy-sync"
 version = "0.6.2"
@@ -515,26 +421,6 @@ dependencies = [
  "embedded-io-async",
 ]
 
-[[package]]
-name = "embassy-usb-synopsys-otg"
-version = "0.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d46be92e72bcf39e623ff74d739a8ab29b02f4909a9b05986ca81c2157ac254a"
-dependencies = [
- "critical-section",
- "embassy-sync 0.5.0",
- "embassy-usb-driver",
-]
-
-[[package]]
-name = "embedded-can"
-version = "0.4.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e9d2e857f87ac832df68fa498d18ddc679175cf3d2e4aa893988e5601baf9438"
-dependencies = [
- "nb 1.1.0",
-]
-
 [[package]]
 name = "embedded-hal"
 version = "0.2.7"
@@ -560,16 +446,6 @@ dependencies = [
  "embedded-hal 1.0.0",
 ]
 
-[[package]]
-name = "embedded-hal-nb"
-version = "1.0.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fba4268c14288c828995299e59b12babdbe170f6c6d73731af1b4648142e8605"
-dependencies = [
- "embedded-hal 1.0.0",
- "nb 1.1.0",
-]
-
 [[package]]
 name = "embedded-io"
 version = "0.6.1"
@@ -606,221 +482,6 @@ version = "0.3.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a357d28ed41a50f9c765dbfe56cbc04a64e53e5fc58ba79fbc34c10ef3df831f"
 
-[[package]]
-name = "enum-as-inner"
-version = "0.6.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a1e6a265c649f3f5979b601d26f1d05ada116434c87741c9493cb56218f76cbc"
-dependencies = [
- "heck",
- "proc-macro2",
- "quote",
- "syn 2.0.117",
-]
-
-[[package]]
-name = "enumset"
-version = "1.1.10"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "25b07a8dfbbbfc0064c0a6bdf9edcf966de6b1c33ce344bdeca3b41615452634"
-dependencies = [
- "enumset_derive",
-]
-
-[[package]]
-name = "enumset_derive"
-version = "0.14.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
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-dependencies = [
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-source = "registry+https://github.com/rust-lang/crates.io-index"
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-
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- "defmt 0.3.100",
- "esp-build",
- "esp-println",
- "semihosting",
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-
-[[package]]
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-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b94a4b8d74e7cc7baabcca5b2277b41877e039ad9cd49959d48ef94dac7eab4b"
-dependencies = [
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- "syn 2.0.117",
- "termcolor",
-]
-
-[[package]]
-name = "esp-config"
-version = "0.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f7584e4cd1dac06201fd92fff1c84b396be5458ac4d93e9457e7a89b1b42c60e"
-dependencies = [
- "document-features",
-]
-
-[[package]]
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-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1a5605e1518d63f7bf9fbd9885e61d2896060d2e4f28954736bdd74da911b676"
-dependencies = [
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- "bitfield 0.17.0",
- "bitflags 2.11.0",
- "bytemuck",
- "cfg-if",
- "chrono",
- "critical-section",
- "delegate",
- "document-features",
- "embassy-embedded-hal",
- "embassy-futures",
- "embassy-sync 0.6.2",
- "embassy-usb-driver",
- "embassy-usb-synopsys-otg",
- "embedded-can",
- "embedded-hal 0.2.7",
- "embedded-hal 1.0.0",
- "embedded-hal-async",
- "embedded-hal-nb",
- "embedded-io",
- "embedded-io-async",
- "enumset",
- "esp-build",
- "esp-config",
- "esp-hal-procmacros",
- "esp-metadata",
- "esp-riscv-rt",
- "esp-synopsys-usb-otg",
- "esp32s3",
- "fugit",
- "nb 1.1.0",
- "paste",
- "portable-atomic",
- "rand_core",
- "serde",
- "strum",
- "ufmt-write",
- "usb-device",
- "void",
- "xtensa-lx",
- "xtensa-lx-rt",
-]
-
-[[package]]
-name = "esp-hal-embassy"
-version = "0.5.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
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-dependencies = [
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- "document-features",
- "embassy-executor",
- "embassy-time-driver",
- "esp-build",
- "esp-config",
- "esp-hal",
- "esp-hal-procmacros",
- "esp-metadata",
- "portable-atomic",
- "static_cell",
-]
-
-[[package]]
-name = "esp-hal-procmacros"
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-source = "registry+https://github.com/rust-lang/crates.io-index"
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-dependencies = [
- "darling 0.20.11",
- "document-features",
- "litrs 0.4.2",
- "object",
- "proc-macro-crate",
- "proc-macro-error2",
- "proc-macro2",
- "quote",
- "syn 2.0.117",
-]
-
-[[package]]
-name = "esp-metadata"
-version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f9972bbb21dcafe430b87f92efc7a788978a2d17cf8f572d104beeb48602482a"
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- "serde",
- "strum",
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-
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-dependencies = [
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- "defmt 0.3.100",
- "esp-build",
- "log",
- "portable-atomic",
-]
-
-[[package]]
-name = "esp-riscv-rt"
-version = "0.9.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "94aca65db6157aa5f42d9df6595b21462f28207ca4230b799aa3620352ef6a72"
-dependencies = [
- "document-features",
- "riscv",
- "riscv-rt-macros",
-]
-
-[[package]]
-name = "esp-synopsys-usb-otg"
-version = "0.4.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8938451cb19032f13365328ea66ab38c8d16deecdf322067442297110eb74468"
-dependencies = [
- "critical-section",
- "embedded-hal 0.2.7",
- "ral-registers",
- "usb-device",
- "vcell",
-]
-
-[[package]]
-name = "esp32s3"
-version = "0.29.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fe69dca8db0ed37d222555f12dfaf99232592e84f54e56dd81e450a4769718bf"
-dependencies = [
- "critical-section",
- "vcell",
-]
-
 [[package]]
 name = "fixed"
 version = "1.31.0"
@@ -839,15 +500,6 @@ version = "1.0.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3f9eec918d3f24069decb9af1554cad7c880e2da24a9afd88aca000531ab82c1"
 
-[[package]]
-name = "fugit"
-version = "0.3.9"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4e639847d312d9a82d2e75b0edcc1e934efcc64e6cb7aa94f0b1fbec0bc231d6"
-dependencies = [
- "gcd",
-]
-
 [[package]]
 name = "futures-core"
 version = "0.3.32"
@@ -877,12 +529,6 @@ dependencies = [
  "pin-project-lite",
 ]
 
-[[package]]
-name = "gcd"
-version = "2.3.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1d758ba1b47b00caf47f24925c0074ecb20d6dfcffe7f6d53395c0465674841a"
-
 [[package]]
 name = "half"
 version = "2.7.1"
@@ -912,12 +558,6 @@ dependencies = [
  "ahash",
 ]
 
-[[package]]
-name = "hashbrown"
-version = "0.16.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "841d1cc9bed7f9236f321df977030373f4a4163ae1a7dbfe1a51a2c1a51d9100"
-
 [[package]]
 name = "heapless"
 version = "0.8.0"
@@ -929,52 +569,18 @@ dependencies = [
  "stable_deref_trait",
 ]
 
-[[package]]
-name = "heck"
-version = "0.5.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2304e00983f87ffb38b55b444b5e3b60a884b5d30c0fca7d82fe33449bbe55ea"
-
 [[package]]
 name = "ident_case"
 version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b9e0384b61958566e926dc50660321d12159025e767c18e043daf26b70104c39"
 
-[[package]]
-name = "indexmap"
-version = "2.13.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7714e70437a7dc3ac8eb7e6f8df75fd8eb422675fc7678aff7364301092b1017"
-dependencies = [
- "equivalent",
- "hashbrown 0.16.1",
-]
-
-[[package]]
-name = "litrs"
-version = "0.4.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f5e54036fe321fd421e10d732f155734c4e4afd610dd556d9a82833ab3ee0bed"
-dependencies = [
- "proc-macro2",
-]
-
 [[package]]
 name = "litrs"
 version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "11d3d7f243d5c5a8b9bb5d6dd2b1602c0cb0b9db1621bafc7ed66e35ff9fe092"
 
-[[package]]
-name = "lock_api"
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-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "224399e74b87b5f3557511d98dff8b14089b3dadafcab6bb93eab67d3aace965"
-dependencies = [
- "scopeguard",
-]
-
 [[package]]
 name = "log"
 version = "0.4.29"
@@ -995,10 +601,6 @@ dependencies = [
  "embassy-sync 0.6.2",
  "embassy-time",
  "embassy-usb",
- "esp-backtrace",
- "esp-hal",
- "esp-hal-embassy",
- "esp-println",
  "heapless",
  "lora-phy",
  "minijinja",
@@ -1028,12 +630,6 @@ dependencies = [
  "num-traits",
 ]
 
-[[package]]
-name = "memchr"
-version = "2.8.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f8ca58f447f06ed17d5fc4043ce1b10dd205e060fb3ce5b979b8ed8e59ff3f79"
-
 [[package]]
 name = "memo-map"
 version = "0.3.3"
@@ -1050,12 +646,6 @@ dependencies = [
  "serde",
 ]
 
-[[package]]
-name = "mutex-trait"
-version = "0.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b4bb1638d419e12f8b1c43d9e639abd0d1424285bdea2f76aa231e233c63cd3a"
-
 [[package]]
 name = "nb"
 version = "0.1.3"
@@ -1212,15 +802,6 @@ dependencies = [
  "autocfg",
 ]
 
-[[package]]
-name = "object"
-version = "0.36.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "62948e14d923ea95ea2c7c86c71013138b66525b86bdc08d2dcc262bdb497b87"
-dependencies = [
- "memchr",
-]
-
 [[package]]
 name = "once_cell"
 version = "1.21.4"
@@ -1243,12 +824,6 @@ dependencies = [
  "defmt 0.3.100",
 ]
 
-[[package]]
-name = "paste"
-version = "1.0.15"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "57c0d7b74b563b49d38dae00a0c37d4d6de9b432382b2892f0574ddcae73fd0a"
-
 [[package]]
 name = "pin-project-lite"
 version = "0.2.17"
@@ -1271,15 +846,6 @@ dependencies = [
  "serde",
 ]
 
-[[package]]
-name = "proc-macro-crate"
-version = "3.5.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e67ba7e9b2b56446f1d419b1d807906278ffa1a658a8a5d8a39dcb1f5a78614f"
-dependencies = [
- "toml_edit 0.25.8+spec-1.1.0",
-]
-
 [[package]]
 name = "proc-macro-error-attr2"
 version = "2.0.0"
@@ -1320,65 +886,12 @@ dependencies = [
  "proc-macro2",
 ]
 
-[[package]]
-name = "r0"
-version = "1.0.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
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-
-[[package]]
-name = "ral-registers"
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-
 [[package]]
 name = "rand_core"
 version = "0.6.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ec0be4795e2f6a28069bec0b5ff3e2ac9bafc99e6a9a7dc3547996c5c816922c"
 
-[[package]]
-name = "riscv"
-version = "0.12.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5ea8ff73d3720bdd0a97925f0bf79ad2744b6da8ff36be3840c48ac81191d7a7"
-dependencies = [
- "critical-section",
- "embedded-hal 1.0.0",
- "paste",
- "riscv-macros",
- "riscv-pac",
-]
-
-[[package]]
-name = "riscv-macros"
-version = "0.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f265be5d634272320a7de94cea15c22a3bfdd4eb42eb43edc528415f066a1f25"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn 2.0.117",
-]
-
-[[package]]
-name = "riscv-pac"
-version = "0.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8188909339ccc0c68cfb5a04648313f09621e8b87dc03095454f1a11f6c5d436"
-
-[[package]]
-name = "riscv-rt-macros"
-version = "0.2.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "30f19a85fe107b65031e0ba8ec60c34c2494069fe910d6c297f5e7cb5a6f76d0"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn 2.0.117",
-]
-
 [[package]]
 name = "rustc_version"
 version = "0.2.3"
@@ -1388,24 +901,6 @@ dependencies = [
  "semver",
 ]
 
-[[package]]
-name = "rustversion"
-version = "1.0.22"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b39cdef0fa800fc44525c84ccb54a029961a8215f9619753635a9c0d2538d46d"
-
-[[package]]
-name = "scopeguard"
-version = "1.2.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "94143f37725109f92c262ed2cf5e59bce7498c01bcc1502d7b9afe439a4e9f49"
-
-[[package]]
-name = "semihosting"
-version = "0.1.25"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f8e4abf97879f4e80db69a9fba7bd64998e9bdad25f58ef045a778e191172fd4"
-
 [[package]]
 name = "semver"
 version = "0.9.0"
@@ -1451,24 +946,6 @@ dependencies = [
  "syn 2.0.117",
 ]
 
-[[package]]
-name = "serde_spanned"
-version = "0.6.9"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bf41e0cfaf7226dca15e8197172c295a782857fcb97fad1808a166870dee75a3"
-dependencies = [
- "serde",
-]
-
-[[package]]
-name = "spin"
-version = "0.9.8"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6980e8d7511241f8acf4aebddbb1ff938df5eebe98691418c4468d0b72a96a67"
-dependencies = [
- "lock_api",
-]
-
 [[package]]
 name = "ssmarshal"
 version = "1.0.0"
@@ -1500,28 +977,6 @@ version = "0.11.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"
 
-[[package]]
-name = "strum"
-version = "0.26.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8fec0f0aef304996cf250b31b5a10dee7980c85da9d759361292b8bca5a18f06"
-dependencies = [
- "strum_macros",
-]
-
-[[package]]
-name = "strum_macros"
-version = "0.26.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4c6bee85a5a24955dc440386795aa378cd9cf82acd5f764469152d2270e581be"
-dependencies = [
- "heck",
- "proc-macro2",
- "quote",
- "rustversion",
- "syn 2.0.117",
-]
-
 [[package]]
 name = "syn"
 version = "1.0.109"
@@ -1544,15 +999,6 @@ dependencies = [
  "unicode-ident",
 ]
 
-[[package]]
-name = "termcolor"
-version = "1.4.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "06794f8f6c5c898b3275aebefa6b8a1cb24cd2c6c79397ab15774837a0bc5755"
-dependencies = [
- "winapi-util",
-]
-
 [[package]]
 name = "thiserror"
 version = "2.0.18"
@@ -1573,89 +1019,12 @@ dependencies = [
  "syn 2.0.117",
 ]
 
-[[package]]
-name = "toml"
-version = "0.8.23"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dc1beb996b9d83529a9e75c17a1686767d148d70663143c7854d8b4a09ced362"
-dependencies = [
- "serde",
- "serde_spanned",
- "toml_datetime 0.6.11",
- "toml_edit 0.22.27",
-]
-
-[[package]]
-name = "toml_datetime"
-version = "0.6.11"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "22cddaf88f4fbc13c51aebbf5f8eceb5c7c5a9da2ac40a13519eb5b0a0e8f11c"
-dependencies = [
- "serde",
-]
-
-[[package]]
-name = "toml_datetime"
-version = "1.1.0+spec-1.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "97251a7c317e03ad83774a8752a7e81fb6067740609f75ea2b585b569a59198f"
-dependencies = [
- "serde_core",
-]
-
-[[package]]
-name = "toml_edit"
-version = "0.22.27"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "41fe8c660ae4257887cf66394862d21dbca4a6ddd26f04a3560410406a2f819a"
-dependencies = [
- "indexmap",
- "serde",
- "serde_spanned",
- "toml_datetime 0.6.11",
- "toml_write",
- "winnow 0.7.15",
-]
-
-[[package]]
-name = "toml_edit"
-version = "0.25.8+spec-1.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "16bff38f1d86c47f9ff0647e6838d7bb362522bdf44006c7068c2b1e606f1f3c"
-dependencies = [
- "indexmap",
- "toml_datetime 1.1.0+spec-1.1.0",
- "toml_parser",
- "winnow 1.0.0",
-]
-
-[[package]]
-name = "toml_parser"
-version = "1.1.0+spec-1.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2334f11ee363607eb04df9b8fc8a13ca1715a72ba8662a26ac285c98aabb4011"
-dependencies = [
- "winnow 1.0.0",
-]
-
-[[package]]
-name = "toml_write"
-version = "0.1.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5d99f8c9a7727884afe522e9bd5edbfc91a3312b36a77b5fb8926e4c31a41801"
-
 [[package]]
 name = "typenum"
 version = "1.19.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "562d481066bde0658276a35467c4af00bdc6ee726305698a55b86e61d7ad82bb"
 
-[[package]]
-name = "ufmt-write"
-version = "0.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e87a2ed6b42ec5e28cc3b94c09982969e9227600b2e3dcbc1db927a84c06bd69"
-
 [[package]]
 name = "unicode-ident"
 version = "1.0.24"
@@ -1700,7 +1069,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bb573c76e7884035ac5e1ab4a81234c187a82b6100140af0ab45757650ccda38"
 dependencies = [
  "byteorder",
- "hashbrown 0.13.2",
+ "hashbrown",
  "log",
  "proc-macro2",
  "quote",
@@ -1736,90 +1105,6 @@ dependencies = [
  "vcell",
 ]
 
-[[package]]
-name = "winapi-util"
-version = "0.1.11"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c2a7b1c03c876122aa43f3020e6c3c3ee5c05081c9a00739faf7503aeba10d22"
-dependencies = [
- "windows-sys",
-]
-
-[[package]]
-name = "windows-link"
-version = "0.2.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f0805222e57f7521d6a62e36fa9163bc891acd422f971defe97d64e70d0a4fe5"
-
-[[package]]
-name = "windows-sys"
-version = "0.61.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ae137229bcbd6cdf0f7b80a31df61766145077ddf49416a728b02cb3921ff3fc"
-dependencies = [
- "windows-link",
-]
-
-[[package]]
-name = "winnow"
-version = "0.7.15"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "df79d97927682d2fd8adb29682d1140b343be4ac0f08fd68b7765d9c059d3945"
-dependencies = [
- "memchr",
-]
-
-[[package]]
-name = "winnow"
-version = "1.0.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a90e88e4667264a994d34e6d1ab2d26d398dcdca8b7f52bec8668957517fc7d8"
-dependencies = [
- "memchr",
-]
-
-[[package]]
-name = "xtensa-lx"
-version = "0.9.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e758f94e1a1f71758f94052a2766dcb12604998eb372b8b2e30576e3ab1ba1e6"
-dependencies = [
- "bare-metal 1.0.0",
- "mutex-trait",
- "spin",
-]
-
-[[package]]
-name = "xtensa-lx-rt"
-version = "0.17.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5c0307d03dadbf95633942e13901984f2059df4c963367348168cbd21c962669"
-dependencies = [
- "anyhow",
- "bare-metal 1.0.0",
- "document-features",
- "enum-as-inner",
- "minijinja",
- "r0",
- "serde",
- "strum",
- "toml",
- "xtensa-lx",
- "xtensa-lx-rt-proc-macros",
-]
-
-[[package]]
-name = "xtensa-lx-rt-proc-macros"
-version = "0.2.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "11277b1e4cbb7ffe44678c668518b249c843c81df249b8f096701757bc50d7ee"
-dependencies = [
- "darling 0.20.11",
- "proc-macro2",
- "quote",
- "syn 2.0.117",
-]
-
 [[package]]
 name = "zerocopy"
 version = "0.8.47"

Cargo.toml

@@ -19,12 +19,6 @@ postcard = { version = "1.0", default-features = false }
 serde = { version = "1.0", default-features = false, features = ["derive"] }
 static_cell = "2.1"
 
-# ESP32-S3 (Heltec V3)
-esp-backtrace = { version = "0.14", optional = true, features = ["esp32s3", "panic-handler", "defmt"] }
-esp-hal = { version = "0.22", optional = true, features = ["esp32s3"] }
-esp-hal-embassy = { version = "0.5", optional = true, features = ["esp32s3"] }
-esp-println = { version = "0.12", optional = true, features = ["esp32s3", "defmt-espflash"] }
-
 # nRF52840 (RAK 4631)
 cortex-m-rt = { version = "0.7", optional = true }
 embassy-nrf = { version = "0.2", optional = true, features = ["nrf52840", "gpiote", "time-driver-rtc1", "defmt"] }
@@ -35,12 +29,6 @@ minijinja = "2.0"
 owo-colors = "4.0"
 
 [features]
-heltec_v3 = [
-    "dep:esp-backtrace",
-    "dep:esp-hal",
-    "dep:esp-hal-embassy",
-    "dep:esp-println",
-]
 rak_4631 = [
     "dep:cortex-m-rt",
     "dep:embassy-nrf",

DESIGN.md

@@ -37,8 +37,8 @@ radio — it just gives you clean access to it.
 6. **Minimal footprint.** Avoid heavy dependencies. Keep the binary small. Every
    dependency must justify its inclusion.
 
-7. **Auto-detect peripherals.** If the board has a display, use it. No user
+7. **Auto-detect peripherals.** If the board has a display, keyboard, or sensors,
-   configuration required.
+   use them. No user configuration required.
 
 8. **World-class Rust.** Fully leverage the type system for safety. Strict `no_std`.
    Always clippy-clean. Thoughtfully designed — everything has an obvious home.
@@ -47,6 +47,11 @@ radio — it just gives you clean access to it.
 9. **Easy board support.** Adding a new board means dropping a `.rs` file and adding
    a Cargo feature. Nothing else changes.
 
+10. **Standard toolchain only.** No custom Rust forks, no `espup`, no special SDKs.
+    If a board can't build with stock `rustup`, it doesn't ship. This rules out
+    Xtensa-based ESP32 chips (S2, S3) until upstream Rust fully supports them.
+    RISC-V ESP32 variants (C3, C6, H2) are fine.
+
 ## Architecture
 
 ```
@@ -63,6 +68,23 @@ usb_task ──Command──► radio_task ──► SX1262
 Each task exclusively owns its peripheral. No shared state except typed channels and
 a watch signal. Pure actor model.
 
+## Peripheral Model
+
+Boards can have optional peripherals beyond the radio and USB. The board's
+`into_parts()` returns `Option<T>` slots for each, and the corresponding task is
+only spawned when present.
+
+| Peripheral | Slot | Task | Examples |
+|---|---|---|---|
+| Display | `Option<DisplayParts>` | `display_task` | SSD1306 OLED, ST7789 TFT |
+| Input | `Option<InputParts>` | `input_task` | T-Deck keyboard, buttons |
+| Telemetry | `Option<TelemetryParts>` | `telemetry_task` | Battery voltage, temperature |
+
+**Board files are always separate.** A T-Deck is `t_deck.rs`, not a variant of
+Heltec V3. Each board owns its own init code and pin mappings. Shared logic between
+boards that use the same MCU can be factored into helper modules if it earns its
+keep, but never prematurely.
+
 ## Technical Decisions
 
 | Decision | Choice | Why |
@@ -74,3 +96,4 @@ a watch signal. Pure actor model.
 | Boot behavior | Idle until host commands | Host-driven principle |
 | Persistence | None | Always start fresh, true dumb pipe |
 | Board codegen | Jinja2 via build.rs | Auto-discovers boards from filesystem |
+| Rust toolchain | Standard `rustup` only | No forks, no espup, no special SDKs |

Justfile

@@ -1,10 +1,8 @@
 set shell := ["bash", "-c"]
-heltec_v3 := "heltec_v3 xtensa-esp32s3-none-elf esp32s3"
+rak_4631 := "rak_4631 thumbv7em-none-eabihf nRF52840_xxAA"
-rak_4631  := "rak_4631 thumbv7em-none-eabihf nRF52840_xxAA"
 
 # Check all boards compile cleanly
 check-all:
-    just check heltec_v3
     just check rak_4631
 
 # Check a single board compiles
@@ -30,6 +28,5 @@ size board:
 
 [private]
 _info name:
-    @if [ "{{name}}" == "heltec_v3" ]; then echo "{{heltec_v3}}"; \
+    @if [ "{{name}}" == "rak_4631" ]; then echo "{{rak_4631}}"; \
-     elif [ "{{name}}" == "rak_4631" ]; then echo "{{rak_4631}}"; \
+     else echo "Unknown board: {{name}}" >&2; exit 1; fi
-     else echo "Unknown board" >&2; exit 1; fi

src/board/heltec_v3.rs

@@ -1,70 +0,0 @@
-use esp_hal::gpio::{GpioPin, Input, Output, PullDown, PushPull};
-use esp_hal::peripherals::SPI2;
-use esp_hal::spi::master::Spi;
-use esp_hal::spi::SpiMode;
-use esp_hal::i2c::I2c;
-use esp_hal::peripherals::I2C0;
-use esp_hal::Delay;
-
-use lora_phy::iv::GenericSx126xInterfaceVariant;
-use lora_phy::sx126x::{self, Sx1262, Sx126x};
-use lora_phy::LoRa;
-
-/// Board name shown on the display dashboard.
-pub const BOARD_NAME: &str = "Heltec V3";
-
-// ── Concrete peripheral types ────────────────────────────────────────
-
-type Iv = GenericSx126xInterfaceVariant<Output<'static, GpioPin<8>>, Input<'static, GpioPin<14>>>;
-type RadioSpi = Spi<'static, SPI2>;
-type RadioDriver = Sx126x<RadioSpi, Iv, Sx1262>;
-
-/// Fully-constructed LoRa radio driver.
-pub type Radio = LoRa<RadioDriver, Delay>;
-
-/// USB driver for CDC-ACM.
-// TODO: define concrete USB OTG type once esp-hal USB support is wired up
-pub type UsbDriver = ();
-
-/// I2C bus for the built-in SSD1306 OLED.
-pub type DisplayI2c = I2c<'static, I2C0>;
-
-// ── Peripheral bundles ───────────────────────────────────────────────
-
-pub struct RadioParts {
-    pub radio: Radio,
-}
-
-pub struct UsbParts {
-    pub driver: UsbDriver,
-}
-
-pub struct DisplayParts {
-    pub i2c: DisplayI2c,
-}
-
-// ── Board init ───────────────────────────────────────────────────────
-
-pub struct Board {
-    p: esp_hal::peripherals::Peripherals,
-}
-
-impl Board {
-    pub fn init() -> Self {
-        let p = esp_hal::init(esp_hal::Config::default());
-        Self { p }
-    }
-
-    pub fn into_parts(self) -> (RadioParts, UsbParts, Option<DisplayParts>) {
-        let _p = self.p;
-
-        // TODO: implement Heltec V3 peripheral init
-        // - SPI2 for SX1262 (SCK=9, MOSI=10, MISO=11, NSS=8)
-        // - GPIO for radio control (RST=12, DIO1=14, BUSY=13)
-        // - Vext pin (GPIO21) LOW to power OLED
-        // - I2C0 for SSD1306 (SDA=17, SCL=18)
-        // - USB OTG for CDC-ACM
-
-        todo!("Heltec V3 peripheral init — requires espup toolchain to develop")
-    }
-}

src/board/rak_4631.rs

@@ -18,10 +18,6 @@ bind_interrupts!(struct Irqs {
     SPIM0_SPIS0_TWIM0_TWIS0_SPI0_TWI0 => embassy_nrf::twim::InterruptHandler<embassy_nrf::peripherals::TWISPI0>;
 });
 
-/// Board name shown on the display dashboard.
-#[allow(dead_code)]
-pub const BOARD_NAME: &str = "RAK 4631";
-
 // ── Concrete peripheral types ────────────────────────────────────────
 
 type SpiBus = Spim<'static, embassy_nrf::peripherals::SPI3>;

src/display/render.rs

@@ -1,4 +1,4 @@
-use crate::channel::{RadioState, RadioStatus};
+use crate::channel::RadioStatus;
 
 /// Render the status dashboard to a framebuffer.
 ///
@@ -13,13 +13,3 @@ pub fn dashboard(status: &RadioStatus) {
     //   Line 5: last RSSI / SNR
     let _ = status;
 }
-
-/// Format radio state as a short display string.
-#[allow(dead_code)]
-pub fn state_label(state: RadioState) -> &'static str {
-    match state {
-        RadioState::Idle => "IDLE",
-        RadioState::Receiving => "RX",
-        RadioState::Transmitting => "TX",
-    }
-}

src/error.rs

@@ -1,16 +0,0 @@
-/// Radio hardware errors.
-#[allow(dead_code)]
-#[derive(Debug, defmt::Format)]
-pub enum RadioError {
-    InitFailed,
-    TxTimeout,
-    InvalidConfig,
-}
-
-/// USB protocol framing errors.
-#[allow(dead_code)]
-#[derive(Debug, defmt::Format)]
-pub enum ProtocolError {
-    DeserializeFailed,
-    BufferOverflow,
-}

src/main.rs

@@ -4,7 +4,6 @@
 mod board;
 mod channel;
 mod display;
-mod error;
 mod protocol;
 mod radio;
 mod usb;
@@ -16,8 +15,6 @@ use crate::channel::{CommandChannel, ResponseChannel, StatusWatch};
 cfg_if::cfg_if! {
     if #[cfg(feature = "rak_4631")] {
         use panic_probe as _;
-    } else if #[cfg(feature = "heltec_v3")] {
-        use esp_backtrace as _;
     }
 }
 

src/protocol.rs

@@ -4,10 +4,6 @@ use serde::{Deserialize, Serialize};
 /// Maximum LoRa payload size in bytes.
 pub const MAX_PAYLOAD: usize = 256;
 
-/// Protocol version for host compatibility checks.
-#[allow(dead_code)]
-pub const PROTOCOL_VERSION: u8 = 1;
-
 /// LoRa signal bandwidth.
 #[derive(Serialize, Deserialize, Debug, Clone, Copy, PartialEq, Eq, defmt::Format)]
 #[repr(u8)]