diff --git a/firmware/rust/.cargo/config.toml b/firmware/rust/.cargo/config.toml
new file mode 100644
index 0000000..e04df30
--- /dev/null
+++ b/firmware/rust/.cargo/config.toml
@@ -0,0 +1,5 @@
+[build]
+target = "avr-specs/avr-atmega328p.json"
+
+[unstable]
+build-std = ["core"]
diff --git a/firmware/rust/.gitignore b/firmware/rust/.gitignore
new file mode 100644
index 0000000..ea8c4bf
--- /dev/null
+++ b/firmware/rust/.gitignore
@@ -0,0 +1 @@
+/target
diff --git a/firmware/rust/Cargo.lock b/firmware/rust/Cargo.lock
new file mode 100644
index 0000000..068b887
--- /dev/null
+++ b/firmware/rust/Cargo.lock
@@ -0,0 +1,215 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+[[package]]
+name = "atmega-hal"
+version = "0.1.0"
+source = "git+https://github.com/rahix/avr-hal?branch=main#e897783816437a677aa577ddfdaa34e9a1e86d96"
+dependencies = [
+ "avr-device",
+ "avr-hal-generic",
+]
+
+[[package]]
+name = "avr-device"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4eb440a38bef22cef233b3eb46ef13e588eb8dcc70a1bdce3f00ebc6bf6b48dd"
+dependencies = [
+ "avr-device-macros",
+ "bare-metal",
+ "cfg-if",
+ "vcell",
+]
+
+[[package]]
+name = "avr-device-macros"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2c62997db86a92e73b68ab491d4379e1ddb12e94a9eb542180bc6b60f0e09f8b"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "avr-hal-generic"
+version = "0.1.0"
+source = "git+https://github.com/rahix/avr-hal?branch=main#e897783816437a677aa577ddfdaa34e9a1e86d96"
+dependencies = [
+ "avr-device",
+ "cfg-if",
+ "embedded-hal",
+ "nb 0.1.3",
+ "paste",
+ "ufmt",
+ "void",
+]
+
+[[package]]
+name = "bare-metal"
+version = "0.2.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5deb64efa5bd81e31fcd1938615a6d98c82eafcbcd787162b6f63b91d6bac5b3"
+dependencies = [
+ "rustc_version",
+]
+
+[[package]]
+name = "cfg-if"
+version = "0.1.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4785bdd1c96b2a846b2bd7cc02e86b6b3dbf14e7e53446c4f54c92a361040822"
+
+[[package]]
+name = "clock-generator"
+version = "0.1.0-dev"
+dependencies = [
+ "atmega-hal",
+ "embedded-hal",
+ "nb 1.0.0",
+ "panic-halt",
+]
+
+[[package]]
+name = "embedded-hal"
+version = "0.2.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "35949884794ad573cf46071e41c9b60efb0cb311e3ca01f7af807af1debc66ff"
+dependencies = [
+ "nb 0.1.3",
+ "void",
+]
+
+[[package]]
+name = "nb"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "801d31da0513b6ec5214e9bf433a77966320625a37860f910be265be6e18d06f"
+dependencies = [
+ "nb 1.0.0",
+]
+
+[[package]]
+name = "nb"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "546c37ac5d9e56f55e73b677106873d9d9f5190605e41a856503623648488cae"
+
+[[package]]
+name = "panic-halt"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "de96540e0ebde571dc55c73d60ef407c653844e6f9a1e2fdbd40c07b9252d812"
+
+[[package]]
+name = "paste"
+version = "1.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0744126afe1a6dd7f394cb50a716dbe086cb06e255e53d8d0185d82828358fb5"
+
+[[package]]
+name = "proc-macro-hack"
+version = "0.5.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dbf0c48bc1d91375ae5c3cd81e3722dff1abcf81a30960240640d223f59fe0e5"
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.36"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c7342d5883fbccae1cc37a2353b09c87c9b0f3afd73f5fb9bba687a1f733b029"
+dependencies = [
+ "unicode-xid",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "864d3e96a899863136fc6e99f3d7cae289dafe43bf2c5ac19b70df7210c0a145"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "rustc_version"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "138e3e0acb6c9fb258b19b67cb8abd63c00679d2851805ea151465464fe9030a"
+dependencies = [
+ "semver",
+]
+
+[[package]]
+name = "semver"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1d7eb9ef2c18661902cc47e535f9bc51b78acd254da71d375c2f6720d9a40403"
+dependencies = [
+ "semver-parser",
+]
+
+[[package]]
+name = "semver-parser"
+version = "0.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "388a1df253eca08550bef6c72392cfe7c30914bf41df5269b68cbd6ff8f570a3"
+
+[[package]]
+name = "syn"
+version = "1.0.86"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8a65b3f4ffa0092e9887669db0eae07941f023991ab58ea44da8fe8e2d511c6b"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-xid",
+]
+
+[[package]]
+name = "ufmt"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2e7ecea7ef79d3f8f878eee614afdf5256475c63ad76139d4da6125617c784a0"
+dependencies = [
+ "proc-macro-hack",
+ "ufmt-macros",
+ "ufmt-write",
+]
+
+[[package]]
+name = "ufmt-macros"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ed813e34a2bfa9dc58ee2ed8c8314d25e6d70c911486d64b8085cb695cfac069"
+dependencies = [
+ "proc-macro-hack",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "ufmt-write"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e87a2ed6b42ec5e28cc3b94c09982969e9227600b2e3dcbc1db927a84c06bd69"
+
+[[package]]
+name = "unicode-xid"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8ccb82d61f80a663efe1f787a51b16b5a51e3314d6ac365b08639f52387b33f3"
+
+[[package]]
+name = "vcell"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "77439c1b53d2303b20d9459b1ade71a83c716e3f9c34f3228c00e6f185d6c002"
+
+[[package]]
+name = "void"
+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6a02e4885ed3bc0f2de90ea6dd45ebcbb66dacffe03547fadbb0eeae2770887d"
diff --git a/firmware/rust/Cargo.toml b/firmware/rust/Cargo.toml
new file mode 100644
index 0000000..d86a122
--- /dev/null
+++ b/firmware/rust/Cargo.toml
@@ -0,0 +1,33 @@
+[package]
+name = "clock-generator"
+version = "0.1.0-dev"
+authors = ["finga <finga@onders.org>"]
+edition = "2018"
+license = "GPL-3.0-or-later"
+
+[[bin]]
+name = "clock-generator"
+test = false
+bench = false
+
+[dependencies]
+panic-halt = "0.2"
+nb = "1.0"
+embedded-hal = "0.2"
+
+[dependencies.atmega-hal]
+git = "https://github.com/rahix/avr-hal"
+branch = "main"
+features = ["atmega328p", "rt"]
+
+[profile.dev]
+panic = "abort"
+lto = true
+opt-level = "s"
+
+[profile.release]
+panic = "abort"
+codegen-units = 1
+debug = true
+lto = true
+opt-level = "s"
diff --git a/firmware/rust/avr-specs/avr-atmega328p.json b/firmware/rust/avr-specs/avr-atmega328p.json
new file mode 100644
index 0000000..e236b08
--- /dev/null
+++ b/firmware/rust/avr-specs/avr-atmega328p.json
@@ -0,0 +1,27 @@
+{
+  "arch": "avr",
+  "atomic-cas": false,
+  "cpu": "atmega328p",
+  "data-layout": "e-P1-p:16:8-i8:8-i16:8-i32:8-i64:8-f32:8-f64:8-n8-a:8",
+  "eh-frame-header": false,
+  "exe-suffix": ".elf",
+  "executables": true,
+  "late-link-args": {
+    "gcc": [
+      "-lgcc"
+    ]
+  },
+  "linker": "avr-gcc",
+  "linker-is-gnu": true,
+  "llvm-target": "avr-unknown-unknown",
+  "max-atomic-width": 8,
+  "no-default-libraries": false,
+  "pre-link-args": {
+    "gcc": [
+      "-mmcu=atmega328p",
+      "-Wl,--as-needed"
+    ]
+  },
+  "target-c-int-width": "16",
+  "target-pointer-width": "16"
+}
diff --git a/firmware/rust/rust-toolchain.toml b/firmware/rust/rust-toolchain.toml
new file mode 100644
index 0000000..6616dd3
--- /dev/null
+++ b/firmware/rust/rust-toolchain.toml
@@ -0,0 +1,4 @@
+[toolchain]
+channel = "nightly-2021-01-07"
+components = [ "rust-src" ]
+profile = "minimal"
diff --git a/firmware/rust/src/main.rs b/firmware/rust/src/main.rs
new file mode 100644
index 0000000..cc4d159
--- /dev/null
+++ b/firmware/rust/src/main.rs
@@ -0,0 +1,20 @@
+#![no_std]
+#![no_main]
+
+use atmega_hal::{clock::MHz8, delay::Delay, pins, Peripherals};
+use embedded_hal::blocking::delay::DelayMs;
+use panic_halt as _;
+
+#[atmega_hal::entry]
+fn main() -> ! {
+    let dp = Peripherals::take().unwrap();
+    let pins = pins!(dp);
+
+    let mut led = pins.pd5.into_output();
+    let mut delay = Delay::<MHz8>::new();
+
+    loop {
+        led.toggle();
+        delay.delay_ms(255_u8);
+    }
+}