From ef60562cf33eb85cc8d3d721c7a5fd3912a56fc6 Mon Sep 17 00:00:00 2001
From: Claas <claas@claas.dev>
Date: Sat, 27 Jul 2024 00:55:42 +0200
Subject: [PATCH] Begin custom MQTT implementation

---
 Cargo.lock                 | 514 +++++++++++++++++++++++++++++--------
 Cargo.toml                 |   2 +-
 fan-controller/Cargo.toml  |   1 +
 fan-controller/src/main.rs |  11 +
 mqtt/Cargo.toml            |  10 +
 mqtt/src/main.rs           | 158 ++++++++++++
 6 files changed, 595 insertions(+), 101 deletions(-)
 create mode 100644 mqtt/Cargo.toml
 create mode 100644 mqtt/src/main.rs

diff --git a/Cargo.lock b/Cargo.lock
index 44abb53..b2630dc 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -124,6 +124,33 @@ version = "1.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0c4b4d0bd25bd0b74681c0ad21497610ce1b7c91b1022cd21c80c6fbdd9476b0"
 
+[[package]]
+name = "aws-lc-rs"
+version = "1.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4ae74d9bd0a7530e8afd1770739ad34b36838829d6ad61818f9230f683f5ad77"
+dependencies = [
+ "aws-lc-sys",
+ "mirai-annotations",
+ "paste",
+ "zeroize",
+]
+
+[[package]]
+name = "aws-lc-sys"
+version = "0.20.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2e89b6941c2d1a7045538884d6e760ccfffdf8e1ffc2613d8efa74305e1f3752"
+dependencies = [
+ "bindgen",
+ "cc",
+ "cmake",
+ "dunce",
+ "fs_extra",
+ "libc",
+ "paste",
+]
+
 [[package]]
 name = "az"
 version = "1.2.1"
@@ -166,6 +193,35 @@ version = "0.21.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9d297deb1925b89f2ccc13d7635fa0714f12c87adce1c75356b39ca9b7178567"
 
+[[package]]
+name = "bbqueue"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fd3baa8859d1a4c7411039a75c0599a4640ef1c9a8fc811e4325b00e6cfe0a55"
+
+[[package]]
+name = "bindgen"
+version = "0.69.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a00dc851838a2120612785d195287475a3ac45514741da670b735818822129a0"
+dependencies = [
+ "bitflags 2.6.0",
+ "cexpr",
+ "clang-sys",
+ "itertools",
+ "lazy_static",
+ "lazycell",
+ "log",
+ "prettyplease",
+ "proc-macro2",
+ "quote",
+ "regex",
+ "rustc-hash",
+ "shlex",
+ "syn 2.0.71",
+ "which",
+]
+
 [[package]]
 name = "bit-set"
 version = "0.5.3"
@@ -241,6 +297,19 @@ name = "cc"
 version = "1.1.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2aba8f4e9906c7ce3c73463f62a7f0c65183ada1a2d47e397cc8810827f9694f"
+dependencies = [
+ "jobserver",
+ "libc",
+]
+
+[[package]]
+name = "cexpr"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6fac387a98bb7c37292057cffc56d62ecb629900026402633ae9160df93a8766"
+dependencies = [
+ "nom",
+]
 
 [[package]]
 name = "cfg-if"
@@ -258,6 +327,26 @@ dependencies = [
  "inout",
 ]
 
+[[package]]
+name = "clang-sys"
+version = "1.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b023947811758c97c59bf9d1c188fd619ad4718dcaa767947df1cadb14f39f4"
+dependencies = [
+ "glob",
+ "libc",
+ "libloading",
+]
+
+[[package]]
+name = "cmake"
+version = "0.1.50"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a31c789563b815f77f4250caee12365734369f942439b7defd71e18a48197130"
+dependencies = [
+ "cc",
+]
+
 [[package]]
 name = "codespan-reporting"
 version = "0.11.1"
@@ -568,6 +657,12 @@ dependencies = [
  "litrs",
 ]
 
+[[package]]
+name = "dunce"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "56ce8c6da7551ec6c462cbaf3bfbc75131ebbfa1c944aeaa9dab51ca1c5f0c3b"
+
 [[package]]
 name = "either"
 version = "1.13.0"
@@ -857,6 +952,17 @@ dependencies = [
  "embedded-io",
 ]
 
+[[package]]
+name = "embedded-nal"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "db9efecb57ab54fa918730f2874d7d37647169c50fa1357fecb81abee840b113"
+dependencies = [
+ "heapless 0.7.17",
+ "nb 1.1.0",
+ "no-std-net 0.5.0",
+]
+
 [[package]]
 name = "embedded-nal"
 version = "0.8.0"
@@ -864,7 +970,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b8a943fad5ed3d3f8a00f1e80f6bba371f1e7f0df28ec38477535eb318dc19cc"
 dependencies = [
  "nb 1.1.0",
- "no-std-net",
+ "no-std-net 0.6.0",
 ]
 
 [[package]]
@@ -874,8 +980,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "72229137a4fc12d239b0b7f50f04b30790678da6d782a0f3f1909bf57ec4b759"
 dependencies = [
  "embedded-io-async",
- "embedded-nal",
- "no-std-net",
+ "embedded-nal 0.8.0",
+ "no-std-net 0.6.0",
 ]
 
 [[package]]
@@ -931,6 +1037,16 @@ version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5443807d6dff69373d433ab9ef5378ad8df50ca6298caf15de6e52e24aaf54d5"
 
+[[package]]
+name = "errno"
+version = "0.3.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "534c5cf6194dfab3db3242765c03bbe257cf92f22b38f6bc0c58d59108a820ba"
+dependencies = [
+ "libc",
+ "windows-sys",
+]
+
 [[package]]
 name = "fan-controller"
 version = "0.1.0"
@@ -948,6 +1064,7 @@ dependencies = [
  "embassy-rp",
  "embassy-time",
  "mqttrust",
+ "mqttrust_core",
  "panic-probe",
  "portable-atomic",
  "reqwless",
@@ -988,6 +1105,31 @@ version = "1.0.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3f9eec918d3f24069decb9af1554cad7c880e2da24a9afd88aca000531ab82c1"
 
+[[package]]
+name = "fs_extra"
+version = "1.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "42703706b716c37f96a77aea830392ad231f44c9e9a67872fa5548707e11b11c"
+
+[[package]]
+name = "fugit"
+version = "0.3.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "17186ad64927d5ac8f02c1e77ccefa08ccd9eaa314d5a4772278aa204a22f7e7"
+dependencies = [
+ "gcd",
+]
+
+[[package]]
+name = "fugit-timer"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d9607bfc4c388f9d629704f56ede4a007546cad417b3bcd6fc7c87dc7edce04a"
+dependencies = [
+ "fugit",
+ "nb 1.1.0",
+]
+
 [[package]]
 name = "futures"
 version = "0.3.30"
@@ -1061,6 +1203,12 @@ dependencies = [
  "pin-utils",
 ]
 
+[[package]]
+name = "gcd"
+version = "2.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1d758ba1b47b00caf47f24925c0074ecb20d6dfcffe7f6d53395c0465674841a"
+
 [[package]]
 name = "generic-array"
 version = "0.12.4"
@@ -1117,6 +1265,12 @@ version = "0.29.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "40ecd4077b5ae9fd2e9e169b102c6c330d0605168eb0e8bf79952b256dbefffd"
 
+[[package]]
+name = "glob"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d2fabcfbdc87f4758337ca535fb41a6d701b65693ce38287d856d1674551ec9b"
+
 [[package]]
 name = "group"
 version = "0.13.0"
@@ -1192,6 +1346,7 @@ dependencies = [
  "atomic-polyfill",
  "hash32 0.2.1",
  "rustc_version 0.4.0",
+ "serde",
  "spin",
  "stable_deref_trait",
 ]
@@ -1237,6 +1392,15 @@ dependencies = [
  "digest",
 ]
 
+[[package]]
+name = "home"
+version = "0.5.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e3d1354bf6b7235cb4a0576c2619fd4ed18183f689b12b006a0ee7329eeff9a5"
+dependencies = [
+ "windows-sys",
+]
+
 [[package]]
 name = "httparse"
 version = "1.9.4"
@@ -1286,7 +1450,7 @@ checksum = "f23ff5ef2b80d608d61efee834934d862cd92461afc0560dedf493e4c033738b"
 dependencies = [
  "hermit-abi",
  "libc",
- "windows-sys 0.52.0",
+ "windows-sys",
 ]
 
 [[package]]
@@ -1298,6 +1462,15 @@ dependencies = [
  "either",
 ]
 
+[[package]]
+name = "jobserver"
+version = "0.1.32"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "48d1dbcbbeb6a7fec7e059840aa538bd62aaccf972c7346c4d9d2059312853d0"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "lalrpop"
 version = "0.19.12"
@@ -1329,12 +1502,34 @@ dependencies = [
  "regex",
 ]
 
+[[package]]
+name = "lazy_static"
+version = "1.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bbd2bcb4c963f2ddae06a2efc7e9f3591312473c50c6685e1f298068316e66fe"
+
+[[package]]
+name = "lazycell"
+version = "1.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "830d08ce1d1d941e6b30645f1a0eb5643013d835ce3779a5fc208261dbe10f55"
+
 [[package]]
 name = "libc"
 version = "0.2.155"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "97b3888a4aecf77e811145cadf6eef5901f4782c53886191b2f693f24761847c"
 
+[[package]]
+name = "libloading"
+version = "0.8.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4979f22fdb869068da03c9f7528f8297c6fd2606bc3a4affe42e6a823fdb8da4"
+dependencies = [
+ "cfg-if",
+ "windows-targets",
+]
+
 [[package]]
 name = "libredox"
 version = "0.1.3"
@@ -1365,6 +1560,12 @@ dependencies = [
  "pkg-config",
 ]
 
+[[package]]
+name = "linux-raw-sys"
+version = "0.4.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "78b3ae25bc7c8c38cec158d1f2757ee79e9b3740fbc7ccf0e59e4b08d793fa89"
+
 [[package]]
 name = "litrs"
 version = "0.4.1"
@@ -1408,6 +1609,12 @@ version = "2.7.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "78ca9ab1a0babb1e7d5695e3530886289c18cf2f87ec19a575a0abdce112e3a3"
 
+[[package]]
+name = "minimal-lexical"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "68354c5c6bd36d73ff3feceb05efa59b6acb7626617f4962be322a825e61f79a"
+
 [[package]]
 name = "miniz_oxide"
 version = "0.7.4"
@@ -1419,13 +1626,30 @@ dependencies = [
 
 [[package]]
 name = "mio"
-version = "0.8.11"
+version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a4a650543ca06a924e8b371db273b2756685faae30f8487da1b56505a8f78b0c"
+checksum = "4569e456d394deccd22ce1c1913e6ea0e54519f577285001215d33557431afe4"
 dependencies = [
+ "hermit-abi",
  "libc",
  "wasi",
- "windows-sys 0.48.0",
+ "windows-sys",
+]
+
+[[package]]
+name = "mirai-annotations"
+version = "1.12.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c9be0862c1b3f26a88803c4a49de6889c10e608b3ee9344e6ef5b45fb37ad3d1"
+
+[[package]]
+name = "mqtt"
+version = "0.1.0"
+dependencies = [
+ "thiserror",
+ "tokio",
+ "tokio-rustls",
+ "webpki-roots",
 ]
 
 [[package]]
@@ -1437,6 +1661,22 @@ dependencies = [
  "heapless 0.7.17",
 ]
 
+[[package]]
+name = "mqttrust_core"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "15d1cddb4f21cfbf6757aeb2ee8723a0b0d7f14199825989af6ccfef15e6a9d1"
+dependencies = [
+ "bbqueue",
+ "defmt",
+ "embedded-nal 0.6.0",
+ "fugit",
+ "fugit-timer",
+ "heapless 0.7.17",
+ "mqttrust",
+ "nb 1.1.0",
+]
+
 [[package]]
 name = "nb"
 version = "0.1.3"
@@ -1469,12 +1709,28 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "no-std-net"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1bcece43b12349917e096cddfa66107277f123e6c96a5aea78711dc601a47152"
+
 [[package]]
 name = "no-std-net"
 version = "0.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "43794a0ace135be66a25d3ae77d41b91615fb68ae937f904090203e81f755b65"
 
+[[package]]
+name = "nom"
+version = "7.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d273983c5a657a70a3e8f2a01329822f3b8c8172b73826411a55751e404a0a4a"
+dependencies = [
+ "memchr",
+ "minimal-lexical",
+]
+
 [[package]]
 name = "nourl"
 version = "0.1.1"
@@ -1493,16 +1749,6 @@ dependencies = [
  "autocfg",
 ]
 
-[[package]]
-name = "num_cpus"
-version = "1.16.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4161fcb6d602d4d2081af7c3a45852d875a03dd337a6bfdd6e06407b61342a43"
-dependencies = [
- "hermit-abi",
- "libc",
-]
-
 [[package]]
 name = "num_enum"
 version = "0.5.11"
@@ -1583,7 +1829,7 @@ dependencies = [
  "libc",
  "redox_syscall",
  "smallvec",
- "windows-targets 0.52.6",
+ "windows-targets",
 ]
 
 [[package]]
@@ -1702,6 +1948,16 @@ version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "925383efa346730478fb4838dbe9137d2a47675ad789c546d150a6e1dd4ab31c"
 
+[[package]]
+name = "prettyplease"
+version = "0.2.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5f12335488a2f3b0a83b14edad48dca9879ce89b2edd10e80237e4e852dd645e"
+dependencies = [
+ "proc-macro2",
+ "syn 2.0.71",
+]
+
 [[package]]
 name = "primeorder"
 version = "0.13.6"
@@ -1845,6 +2101,21 @@ dependencies = [
  "rand_core",
 ]
 
+[[package]]
+name = "ring"
+version = "0.17.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c17fa4cb658e3583423e915b9f3acc01cceaee1860e33d59ebae66adc3a2dc0d"
+dependencies = [
+ "cc",
+ "cfg-if",
+ "getrandom",
+ "libc",
+ "spin",
+ "untrusted",
+ "windows-sys",
+]
+
 [[package]]
 name = "rp-pac"
 version = "6.0.0"
@@ -1870,6 +2141,12 @@ version = "0.1.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "719b953e2095829ee67db738b3bfa9fa368c94900df327b3f07fe6e794d2fe1f"
 
+[[package]]
+name = "rustc-hash"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "08d43f7aa6b08d49f382cde6a7982047c3426db949b1424bc4b7ec9ae12c6ce2"
+
 [[package]]
 name = "rustc_version"
 version = "0.2.3"
@@ -1888,6 +2165,52 @@ dependencies = [
  "semver 1.0.23",
 ]
 
+[[package]]
+name = "rustix"
+version = "0.38.34"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "70dc5ec042f7a43c4a73241207cecc9873a06d45debb38b329f8541d85c2730f"
+dependencies = [
+ "bitflags 2.6.0",
+ "errno",
+ "libc",
+ "linux-raw-sys",
+ "windows-sys",
+]
+
+[[package]]
+name = "rustls"
+version = "0.23.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c58f8c84392efc0a126acce10fa59ff7b3d2ac06ab451a33f2741989b806b044"
+dependencies = [
+ "aws-lc-rs",
+ "log",
+ "once_cell",
+ "rustls-pki-types",
+ "rustls-webpki",
+ "subtle",
+ "zeroize",
+]
+
+[[package]]
+name = "rustls-pki-types"
+version = "1.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "976295e77ce332211c0d24d92c0e83e50f5c5f046d11082cea19f3df13a3562d"
+
+[[package]]
+name = "rustls-webpki"
+version = "0.102.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8e6b52d4fda176fd835fdc55a835d4a89b8499cad995885a21149d5ad62f852e"
+dependencies = [
+ "aws-lc-rs",
+ "ring",
+ "rustls-pki-types",
+ "untrusted",
+]
+
 [[package]]
 name = "rustversion"
 version = "1.0.17"
@@ -1985,6 +2308,12 @@ dependencies = [
  "digest",
 ]
 
+[[package]]
+name = "shlex"
+version = "1.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0fda2ff0d084019ba4d7c6f371c95d8fd75ce3524c3cb8fb653a3023f6323e64"
+
 [[package]]
 name = "signal-hook-registry"
 version = "1.4.2"
@@ -2027,7 +2356,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ce305eb0b4296696835b71df73eb912e0f1ffd2556a501fcede6e0c50349191c"
 dependencies = [
  "libc",
- "windows-sys 0.52.0",
+ "windows-sys",
 ]
 
 [[package]]
@@ -2152,34 +2481,44 @@ dependencies = [
 
 [[package]]
 name = "tokio"
-version = "1.38.1"
+version = "1.39.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "eb2caba9f80616f438e09748d5acda951967e1ea58508ef53d9c6402485a46df"
+checksum = "d040ac2b29ab03b09d4129c2f5bbd012a3ac2f79d38ff506a4bf8dd34b0eac8a"
 dependencies = [
  "backtrace",
  "bytes",
  "libc",
  "mio",
- "num_cpus",
  "parking_lot",
  "pin-project-lite",
  "signal-hook-registry",
  "socket2",
  "tokio-macros",
- "windows-sys 0.48.0",
+ "windows-sys",
 ]
 
 [[package]]
 name = "tokio-macros"
-version = "2.3.0"
+version = "2.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5f5ae998a069d4b5aba8ee9dad856af7d520c3699e6159b185c2acd48155d39a"
+checksum = "693d596312e88961bc67d7f1f97af8a70227d9f90c31bba5806eec004978d752"
 dependencies = [
  "proc-macro2",
  "quote",
  "syn 2.0.71",
 ]
 
+[[package]]
+name = "tokio-rustls"
+version = "0.26.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0c7bc40d0e5a97695bb96e27995cd3a08538541b0a846f65bba7a359f36700d4"
+dependencies = [
+ "rustls",
+ "rustls-pki-types",
+ "tokio",
+]
+
 [[package]]
 name = "typenum"
 version = "1.17.0"
@@ -2223,6 +2562,12 @@ dependencies = [
  "subtle",
 ]
 
+[[package]]
+name = "untrusted"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8ecb6da28b8a351d773b68d5825ac39017e680750f980f3a1a85cd8dd28a47c1"
+
 [[package]]
 name = "vcell"
 version = "0.1.3"
@@ -2256,6 +2601,27 @@ version = "0.11.0+wasi-snapshot-preview1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"
 
+[[package]]
+name = "webpki-roots"
+version = "0.26.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bd7c23921eeb1713a4e851530e9b9756e4fb0e89978582942612524cf09f01cd"
+dependencies = [
+ "rustls-pki-types",
+]
+
+[[package]]
+name = "which"
+version = "4.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "87ba24419a2078cd2b0f2ede2691b6c66d8e47836da3b6db8265ebad47afbfc7"
+dependencies = [
+ "either",
+ "home",
+ "once_cell",
+ "rustix",
+]
+
 [[package]]
 name = "winapi"
 version = "0.3.9"
@@ -2278,7 +2644,7 @@ version = "0.1.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4d4cc384e1e73b93bafa6fb4f1df8c41695c8a91cf9c4c64358067d15a7b6c6b"
 dependencies = [
- "windows-sys 0.52.0",
+ "windows-sys",
 ]
 
 [[package]]
@@ -2287,37 +2653,13 @@ version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
 
-[[package]]
-name = "windows-sys"
-version = "0.48.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "677d2418bec65e3338edb076e806bc1ec15693c5d0104683f2efe857f61056a9"
-dependencies = [
- "windows-targets 0.48.5",
-]
-
 [[package]]
 name = "windows-sys"
 version = "0.52.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "282be5f36a8ce781fad8c8ae18fa3f9beff57ec1b52cb3de0789201425d9a33d"
 dependencies = [
- "windows-targets 0.52.6",
-]
-
-[[package]]
-name = "windows-targets"
-version = "0.48.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9a2fa6e2155d7247be68c096456083145c183cbbbc2764150dda45a87197940c"
-dependencies = [
- "windows_aarch64_gnullvm 0.48.5",
- "windows_aarch64_msvc 0.48.5",
- "windows_i686_gnu 0.48.5",
- "windows_i686_msvc 0.48.5",
- "windows_x86_64_gnu 0.48.5",
- "windows_x86_64_gnullvm 0.48.5",
- "windows_x86_64_msvc 0.48.5",
+ "windows-targets",
 ]
 
 [[package]]
@@ -2326,46 +2668,28 @@ version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9b724f72796e036ab90c1021d4780d4d3d648aca59e491e6b98e725b84e99973"
 dependencies = [
- "windows_aarch64_gnullvm 0.52.6",
- "windows_aarch64_msvc 0.52.6",
- "windows_i686_gnu 0.52.6",
+ "windows_aarch64_gnullvm",
+ "windows_aarch64_msvc",
+ "windows_i686_gnu",
  "windows_i686_gnullvm",
- "windows_i686_msvc 0.52.6",
- "windows_x86_64_gnu 0.52.6",
- "windows_x86_64_gnullvm 0.52.6",
- "windows_x86_64_msvc 0.52.6",
+ "windows_i686_msvc",
+ "windows_x86_64_gnu",
+ "windows_x86_64_gnullvm",
+ "windows_x86_64_msvc",
 ]
 
-[[package]]
-name = "windows_aarch64_gnullvm"
-version = "0.48.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2b38e32f0abccf9987a4e3079dfb67dcd799fb61361e53e2882c3cbaf0d905d8"
-
 [[package]]
 name = "windows_aarch64_gnullvm"
 version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "32a4622180e7a0ec044bb555404c800bc9fd9ec262ec147edd5989ccd0c02cd3"
 
-[[package]]
-name = "windows_aarch64_msvc"
-version = "0.48.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dc35310971f3b2dbbf3f0690a219f40e2d9afcf64f9ab7cc1be722937c26b4bc"
-
 [[package]]
 name = "windows_aarch64_msvc"
 version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "09ec2a7bb152e2252b53fa7803150007879548bc709c039df7627cabbd05d469"
 
-[[package]]
-name = "windows_i686_gnu"
-version = "0.48.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a75915e7def60c94dcef72200b9a8e58e5091744960da64ec734a6c6e9b3743e"
-
 [[package]]
 name = "windows_i686_gnu"
 version = "0.52.6"
@@ -2378,48 +2702,24 @@ version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0eee52d38c090b3caa76c563b86c3a4bd71ef1a819287c19d586d7334ae8ed66"
 
-[[package]]
-name = "windows_i686_msvc"
-version = "0.48.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8f55c233f70c4b27f66c523580f78f1004e8b5a8b659e05a4eb49d4166cca406"
-
 [[package]]
 name = "windows_i686_msvc"
 version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "240948bc05c5e7c6dabba28bf89d89ffce3e303022809e73deaefe4f6ec56c66"
 
-[[package]]
-name = "windows_x86_64_gnu"
-version = "0.48.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "53d40abd2583d23e4718fddf1ebec84dbff8381c07cae67ff7768bbf19c6718e"
-
 [[package]]
 name = "windows_x86_64_gnu"
 version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "147a5c80aabfbf0c7d901cb5895d1de30ef2907eb21fbbab29ca94c5b08b1a78"
 
-[[package]]
-name = "windows_x86_64_gnullvm"
-version = "0.48.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0b7b52767868a23d5bab768e390dc5f5c55825b6d30b86c844ff2dc7414044cc"
-
 [[package]]
 name = "windows_x86_64_gnullvm"
 version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "24d5b23dc417412679681396f2b49f3de8c1473deb516bd34410872eff51ed0d"
 
-[[package]]
-name = "windows_x86_64_msvc"
-version = "0.48.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ed94fce61571a4006852b7389a063ab983c02eb1bb37b47f8272ce92d06d9538"
-
 [[package]]
 name = "windows_x86_64_msvc"
 version = "0.52.6"
@@ -2431,3 +2731,17 @@ name = "zeroize"
 version = "1.8.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ced3678a2879b30306d323f4542626697a464a97c0a07c9aebf7ebca65cd4dde"
+dependencies = [
+ "zeroize_derive",
+]
+
+[[package]]
+name = "zeroize_derive"
+version = "1.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ce36e65b0d2999d2aafac989fb249189a141aee1f53c612c1f37d72631959f69"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.71",
+]
diff --git a/Cargo.toml b/Cargo.toml
index 3fbf864..61f9b2e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,3 +1,3 @@
 [workspace]
-members = ["debug-listener", "fan-controller", ]
+members = ["debug-listener", "fan-controller", "mqtt", ]
 resolver = "2"
diff --git a/fan-controller/Cargo.toml b/fan-controller/Cargo.toml
index 112a584..a94ad11 100644
--- a/fan-controller/Cargo.toml
+++ b/fan-controller/Cargo.toml
@@ -17,6 +17,7 @@ embassy-net = { version = "0.4.0", features = ["defmt", "tcp", "dhcpv4", "dns"]
 embassy-rp = { version = "0.1.0", features = ["defmt", "unstable-pac", "time-driver", "critical-section-impl"] }
 embassy-time = "0.3.1"
 mqttrust = "0.6.0"
+mqttrust_core = { version = "0.6.0", features = ["defmt"] }
 panic-probe = "0.3.2"
 portable-atomic = { version = "1.7", features = ["critical-section"] }
 reqwless = { version = "0.12.1", features = ["defmt"] }
diff --git a/fan-controller/src/main.rs b/fan-controller/src/main.rs
index a78f320..77bf4dc 100644
--- a/fan-controller/src/main.rs
+++ b/fan-controller/src/main.rs
@@ -29,6 +29,7 @@ use embassy_rp::{bind_interrupts, uart, Peripherals, Peripheral, pio, dma};
 use embassy_rp::clocks::RoscRng;
 use embassy_rp::spi::ClkPin;
 use embassy_time::{Duration, Timer};
+use mqttrust_core::bbqueue::BBBuffer;
 use reqwless::client::{TlsConfig, TlsVerify};
 use static_cell::StaticCell;
 use {defmt_rtt as _, panic_probe as _};
@@ -199,6 +200,16 @@ async fn setup_tls(spawner: Spawner, net_device: NetDriver, mut control: Control
         //TODO consider increasing security by including a pre shared key otherwise this is
         // vulnerable to man in the middle attacks
         let tls_configuration = TlsConfig::new(seed, &mut tls_read_buffer, &mut tls_write_buffer, TlsVerify::None);
+
+
+        // MQTT stuff following the examples in the mqttrust repository
+        static mut BUFFER: BBBuffer<{ 1024 * 6 }> = BBBuffer::new();
+
+        let (producer, consumer) = unsafe { BUFFER.try_split_framed().unwrap() };
+
+        let client_id = "mqtt_test_client_id";
+
+        let client = mqttrust_core::Client::new(producer, client_id);
     }
 }
 
diff --git a/mqtt/Cargo.toml b/mqtt/Cargo.toml
new file mode 100644
index 0000000..c78e699
--- /dev/null
+++ b/mqtt/Cargo.toml
@@ -0,0 +1,10 @@
+[package]
+name = "mqtt"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+thiserror = "1.0.63"
+tokio = { version = "1.39.1", features = ["full"] }
+tokio-rustls = "0.26.0"
+webpki-roots = "0.26.3"
diff --git a/mqtt/src/main.rs b/mqtt/src/main.rs
new file mode 100644
index 0000000..c30f28e
--- /dev/null
+++ b/mqtt/src/main.rs
@@ -0,0 +1,158 @@
+use std::net::{AddrParseError, SocketAddr, ToSocketAddrs};
+use std::str::FromStr;
+use std::sync::Arc;
+use tokio::net::TcpStream;
+use tokio_rustls::rustls::{ClientConfig, RootCertStore};
+use tokio_rustls::rustls::pki_types::{InvalidDnsNameError, ServerName};
+use tokio_rustls::TlsConnector;
+
+const MQTT_BROKER_ADDRESS: &str = "91c57a00c93443dc90b40bfcaefa7aa3.s1.eu.hivemq.cloud";
+
+#[derive(Debug, thiserror::Error)]
+enum AppError {
+    #[error("Failed to create address")]
+    CreateAddressError(#[from] AddrParseError),
+    #[error("Could not create server name")]
+    CreateServerNameError(#[from] InvalidDnsNameError),
+    #[error("Failed to connect to broker")]
+    ConnectError(#[from] std::io::Error),
+}
+
+/// Encodes an integer as variable byte integer according to the MQTT specification
+fn encode_variable_byte_integer(mut x: u32) -> Vec<u8> {
+    // Each byte can hold 7 bits, so how many 7 bit "bytes" do we need for 32 bits?
+    // 32 / 7
+    let length = 32usize.div_ceil(7);
+    let mut output = Vec::with_capacity(length);
+    loop {
+        // 128 = 0b1000_0000
+
+        // x = 128 = 0b1000_0000
+        // encoded_byte = 128 % 0b1000_0000 = 0
+        let mut encoded_byte = (x % 0b1000_0000);
+        println!("Encoded byte (remainder): {encoded_byte:#010b} {encoded_byte} {x} {}", 0x00_00_80_01_u32);
+
+        // x = 128 / 128 = 1
+        x = x / 0b1000_0000;
+        // If there is more data to encode, set the top bit of this byte
+        if x > 0 {
+            encoded_byte |= 0b1000_0000;
+        }
+
+        output.push(encoded_byte as u8);
+
+        if x > 0 {
+            continue;
+        } else {
+            break;
+        }
+    }
+
+    output
+}
+
+#[test]
+fn can_encode_variable_byte_integer() {
+    // Random examples from https://www.emqx.com/en/blog/mqtt-5-0-control-packets-01-connect-connack
+    assert_eq!(encode_variable_byte_integer(47), [0x2f]);
+    assert_eq!(encode_variable_byte_integer(19), [0x13]);
+
+    // Range one byte
+    assert_eq!(encode_variable_byte_integer(0), [0b0000_0000]);
+    assert_eq!(encode_variable_byte_integer(1), [0b0000_0001]);
+    assert_eq!(encode_variable_byte_integer(127), [0b0111_1111]);
+    // Range two bytes
+    assert_eq!(encode_variable_byte_integer(128), [0b1000_0000, 0b0000_0001]);
+    assert_eq!(encode_variable_byte_integer(16_383), [0b1111_1111, 0b0111_1111]);
+
+    // Range three bytes
+    assert_eq!(encode_variable_byte_integer(16_384), [0b1000_0000, 0b1000_0000, 0b0000_0001]);
+    assert_eq!(encode_variable_byte_integer(2_097_151), [0b1111_1111, 0b1111_1111, 0b0111_1111]);
+    // Range four bytes
+    assert_eq!(encode_variable_byte_integer(2_097_152), [0b1000_0000, 0b1000_0000, 0b1000_0000, 0b0000_0001]);
+    assert_eq!(encode_variable_byte_integer(268_435_455), [0b1111_1111, 0b1111_1111, 0b1111_1111, 0b0111_1111]);
+}
+
+#[derive(Debug)]
+enum DecodeVariableByteIntegerError {
+    MalformedVariableByteIntegerError,
+    UnexpectedEndOfInput,
+}
+
+
+fn decode_variable_byte_integer(bytes: impl IntoIterator<Item=u8> + std::fmt::Debug) -> Result<u32, DecodeVariableByteIntegerError> {
+    dbg!(&bytes);
+    let mut multiplier = 1;
+    let mut value: u32 = 0;
+
+    let mut bytes = bytes.into_iter();
+    loop {
+        let encoded_byte = bytes.next().ok_or(DecodeVariableByteIntegerError::UnexpectedEndOfInput)?;
+        dbg!(encoded_byte);
+
+        value += (encoded_byte & 127) as u32 * multiplier;
+
+        if multiplier > 128 * 128 * 128 {
+            return Err(DecodeVariableByteIntegerError::MalformedVariableByteIntegerError);
+        }
+
+        multiplier *= 128;
+
+        // The last byte has the most significant bit set to 0 indicating that there are no more bytes to follow
+        if (encoded_byte & 128) != 0 {
+            continue;
+        } else {
+            break;
+        }
+    }
+
+    Ok(value)
+}
+
+#[test]
+fn can_decode_variable_byte_integer() {
+    // Random examples from https://www.emqx.com/en/blog/mqtt-5-0-control-packets-01-connect-connack
+    assert_eq!(decode_variable_byte_integer([0x2f]).unwrap(), 47);
+    assert_eq!(decode_variable_byte_integer([0x13]).unwrap(), 19);
+
+    // Range one byte
+    assert_eq!(decode_variable_byte_integer([0b0000_0000]).unwrap(), 0);
+    assert_eq!(decode_variable_byte_integer([0b0000_0001]).unwrap(), 1);
+    assert_eq!(decode_variable_byte_integer([0b0111_1111]).unwrap(), 127);
+
+    // Range two bytes
+    assert_eq!(decode_variable_byte_integer([0b1000_0000, 0b0000_0001]).unwrap(), 128);
+    assert_eq!(decode_variable_byte_integer([0b1111_1111, 0b0111_1111]).unwrap(), 16_383);
+
+    // Range three bytes
+    assert_eq!(decode_variable_byte_integer([0b1000_0000, 0b1000_0000, 0b0000_0001]).unwrap(), 16_384);
+    assert_eq!(decode_variable_byte_integer([0b1111_1111, 0b1111_1111, 0b0111_1111]).unwrap(), 2_097_151);
+
+    // Range four bytes
+    assert_eq!(decode_variable_byte_integer([0b1000_0000, 0b1000_0000, 0b1000_0000, 0b0000_0001]).unwrap(), 2_097_152);
+    assert_eq!(decode_variable_byte_integer([0b1111_1111, 0b1111_1111, 0b1111_1111, 0b0111_1111]).unwrap(), 268_435_455);
+}
+
+#[tokio::main]
+async fn main() -> Result<(), AppError> {
+    let mut root_certificate_store = RootCertStore::empty();
+    root_certificate_store.extend(webpki_roots::TLS_SERVER_ROOTS.iter().cloned());
+    let configuration = ClientConfig::builder()
+        .with_root_certificates(root_certificate_store)
+        .with_no_client_auth();
+    let connector = TlsConnector::from(Arc::new(configuration));
+    let address = (MQTT_BROKER_ADDRESS, 8883).to_socket_addrs()?.next().unwrap();
+    // let address = SocketAddr::from_str(MQTT_BROKER_ADDRESS)?;
+    let server_name = ServerName::try_from("91c57a00c93443dc90b40bfcaefa7aa3.s1.eu.hivemq.cloud")?;
+
+    let stream = TcpStream::connect(&address).await?;
+    let mut stream = connector.connect(server_name, stream).await?;
+
+    // MQTT
+    // Connection request
+    let fixed_header = 0b001_0000_u8;
+
+
+    println!("Hello, world! {fixed_header}");
+    Ok(())
+}
-- 
2.51.2