Compare revisions

Stephen D · Stephen D · Stephen D · Stephen D · Stephen D · Stephen D
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -3,9 +3,12 @@ image: "rust:latest"
 stages:
  - lint
  - build
+  - build-flasher

 before_script:
+  - apt update && apt install -y binutils-arm-none-eabi gcc-mingw-w64-x86-64-win32
  - rustup target add thumbv7em-none-eabihf
+  - rustup target add x86_64-pc-windows-gnu
  - rustup component add rustfmt
  - rustup component add clippy
  - cargo install flip-link
@@ -20,6 +23,25 @@ build:
  stage: build
  script:
    - cargo build --release
+    - cp target/thumbv7em-none-eabihf/release/cats-mobile-transceiver-mainboard firmware.bin
+    - arm-none-eabi-strip firmware.bin
  artifacts:
    paths:
-      - target/thumbv7em-none-eabihf/release/cats-mobile-transceiver-mainboard
+      - firmware.bin
+
+build-flasher:
+  stage: build-flasher
+  script:
+    - mkdir flasher
+    - cd ..
+    - git clone https://gitlab.scd31.com/cats/firmware-flasher
+    - cd firmware-flasher
+    - cp ../mobile-transceiver-software/firmware.bin firmware.bin
+    - cargo build --release
+    - cargo build --release --target x86_64-pc-windows-gnu
+    - cp target/release/stm32-firmware-flasher ../mobile-transceiver-software/flasher/flasher-linux
+    - strip ../mobile-transceiver-software/flasher/flasher-linux
+    - cp target/x86_64-pc-windows-gnu/release/stm32-firmware-flasher.exe ../mobile-transceiver-software/flasher/flasher-windows.exe
+  artifacts:
+    paths:
+      - flasher/*
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -7,6 +7,9 @@ name = "arrayvec"
 version = "0.7.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "96d30a06541fbafbc7f82ed10c06164cfbd2c401138f6addd8404629c4b16711"
+dependencies = [
+ "serde",
+]

 [[package]]
 name = "atomic-polyfill"
@@ -46,9 +49,9 @@ checksum = "46afbd2983a5d5a7bd740ccb198caf5b82f45c40c09c0eed36052d91cb92e719"

 [[package]]
 name = "bitflags"
-version = "2.4.1"
+version = "2.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "327762f6e5a765692301e5bb513e0d9fef63be86bbc14528052b1cd3e6f03e07"
+checksum = "ed570934406eb16438a4e976b1b4500774099c13b8cb96eec99f620f05090ddf"

 [[package]]
 name = "bitvec"
@@ -70,7 +73,7 @@ checksum = "1fd0f2584146f6f2ef48085050886acf353beff7305ebd1ae69500e27c67f64b"

 [[package]]
 name = "cats-mobile-transceiver-mainboard"
-version = "0.2.0"
+version = "0.2.1"
 dependencies = [
 "arrayvec",
 "cortex-m",
@@ -84,8 +87,10 @@ dependencies = [
 "nmea",
 "num-traits",
 "panic-reset",
+ "postcard",
 "rand",
 "rf4463",
+ "serde",
 "stm32f4xx-hal",
 "systick-monotonic",
 "usb-device",
@@ -101,13 +106,19 @@ checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"

 [[package]]
 name = "chrono"
-version = "0.4.31"
+version = "0.4.33"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7f2c685bad3eb3d45a01354cedb7d5faa66194d1d58ba6e267a8de788f79db38"
+checksum = "9f13690e35a5e4ace198e7beea2895d29f3a9cc55015fcebe6336bd2010af9eb"
 dependencies = [
 "num-traits",
 ]

+[[package]]
+name = "cobs"
+version = "0.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "67ba02a97a2bd10f4b59b25c7973101c79642302776489e030cd13cdab09ed15"
+
 [[package]]
 name = "cortex-m"
 version = "0.7.7"
@@ -138,7 +149,7 @@ checksum = "f0f6f3e36f203cfedbc78b357fb28730aa2c6dc1ab060ee5c2405e843988d3c7"
 dependencies = [
 "proc-macro2",
 "quote",
- "syn",
+ "syn 1.0.109",
 ]

 [[package]]
@@ -166,7 +177,7 @@ dependencies = [
 "proc-macro2",
 "quote",
 "rtic-syntax",
- "syn",
+ "syn 1.0.109",
 ]

 [[package]]
@@ -207,9 +218,9 @@ checksum = "7a81dae078cea95a014a339291cec439d2f232ebe854a9d672b796c6afafa9b7"

 [[package]]
 name = "deranged"
-version = "0.3.10"
+version = "0.3.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8eb30d70a07a3b04884d2677f06bec33509dc67ca60d92949e5535352d3191dc"
+checksum = "b42b6fa04a440b495c8b04d0e71b707c585f83cb9cb28cf8cd0d976c315e31b4"
 dependencies = [
 "powerfmt",
 ]
@@ -307,7 +318,7 @@ dependencies = [
 [[package]]
 name = "ham-cats"
 version = "0.2.0"
-source = "git+https://gitlab.scd31.com/cats/ham-cats#79ba39217c85f023b8571d789f279e96eac548b8"
+source = "git+https://gitlab.scd31.com/cats/ham-cats#846af8f55b2398da94da31737287b57caf419505"
 dependencies = [
 "arrayvec",
 "bitvec",
@@ -343,6 +354,7 @@ dependencies = [
 "atomic-polyfill",
 "hash32",
 "rustc_version 0.4.0",
+ "serde",
 "spin",
 "stable_deref_trait",
 ]
@@ -366,8 +378,7 @@ dependencies = [
 [[package]]
 name = "labrador-ldpc"
 version = "1.1.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "23c19ea22fc166b77441be6ea377e5aa20121490cdec0af18a14356d390f45b5"
+source = "git+https://github.com/adamgreig/labrador-ldpc#a6b1b1feb65ec3eae5bb1797f2e4798d4fcee92e"

 [[package]]
 name = "libm"
@@ -387,9 +398,9 @@ dependencies = [

 [[package]]
 name = "memchr"
-version = "2.6.4"
+version = "2.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f665ee40bc4a3c5590afb1e9677db74a508659dfd71e126420da8274909a0167"
+checksum = "523dc4f511e55ab87b694dc30d0f820d60906ef06413f93d4d7a1385599cc149"

 [[package]]
 name = "minimal-lexical"
@@ -436,6 +447,12 @@ dependencies = [
 "minimal-lexical",
 ]

+[[package]]
+name = "num-conv"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "51d515d32fb182ee37cda2ccdcb92950d6a3c2893aa280e540671c2cd0f3b1d9"
+
 [[package]]
 name = "num-traits"
 version = "0.2.17"
@@ -461,6 +478,17 @@ version = "1.0.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "de3145af08024dea9fa9914f381a17b8fc6034dfb00f3a84013f7ff43f29ed4c"

+[[package]]
+name = "postcard"
+version = "1.0.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a55c51ee6c0db07e68448e336cf8ea4131a620edefebf9893e759b2d793420f8"
+dependencies = [
+ "cobs",
+ "heapless",
+ "serde",
+]
+
 [[package]]
 name = "powerfmt"
 version = "0.2.0"
@@ -476,7 +504,7 @@ dependencies = [
 "proc-macro-error-attr",
 "proc-macro2",
 "quote",
- "syn",
+ "syn 1.0.109",
 "version_check",
 ]

@@ -493,18 +521,18 @@ dependencies = [

 [[package]]
 name = "proc-macro2"
-version = "1.0.70"
+version = "1.0.78"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "39278fbbf5fb4f646ce651690877f89d1c5811a3d4acb27700c1cb3cdb78fd3b"
+checksum = "e2422ad645d89c99f8f3e6b88a9fdeca7fabeac836b1002371c4367c8f984aae"
 dependencies = [
 "unicode-ident",
 ]

 [[package]]
 name = "quote"
-version = "1.0.33"
+version = "1.0.35"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5267fca4496028628a95160fc423a33e8b2e6af8a5302579e322e4b520293cae"
+checksum = "291ec9ab5efd934aaf503a6466c5d5251535d108ee747472c3977cc5acc868ef"
 dependencies = [
 "proc-macro2",
 ]
@@ -533,7 +561,7 @@ checksum = "ec0be4795e2f6a28069bec0b5ff3e2ac9bafc99e6a9a7dc3547996c5c816922c"
 [[package]]
 name = "rf4463"
 version = "0.1.0"
-source = "git+https://gitlab.scd31.com/stephen/rf4463-lib#79c8def87540f8ab2663bfa3c9fb13db344ef84e"
+source = "git+https://gitlab.scd31.com/stephen/rf4463-lib#e6ef9a2fd2c64bff5ea7c1716dcc21943add0c2d"
 dependencies = [
 "embedded-hal 0.2.7",
 ]
@@ -559,7 +587,7 @@ dependencies = [
 "indexmap",
 "proc-macro2",
 "quote",
- "syn",
+ "syn 1.0.109",
 ]

 [[package]]
@@ -577,7 +605,7 @@ version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bfa0f585226d2e68097d4f95d113b15b83a82e819ab25717ec0590d9584ef366"
 dependencies = [
- "semver 1.0.20",
+ "semver 1.0.21",
 ]

 [[package]]
@@ -597,9 +625,9 @@ dependencies = [

 [[package]]
 name = "semver"
-version = "1.0.20"
+version = "1.0.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "836fa6a3e1e547f9a2c4040802ec865b5d85f4014efe00555d7090a3dcaa1090"
+checksum = "b97ed7a9823b74f99c7742f5336af7be5ecd3eeafcb1507d1fa93347b1d589b0"

 [[package]]
 name = "semver-parser"
@@ -607,6 +635,26 @@ version = "0.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "388a1df253eca08550bef6c72392cfe7c30914bf41df5269b68cbd6ff8f570a3"

+[[package]]
+name = "serde"
+version = "1.0.196"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "870026e60fa08c69f064aa766c10f10b1d62db9ccd4d0abb206472bee0ce3b32"
+dependencies = [
+ "serde_derive",
+]
+
+[[package]]
+name = "serde_derive"
+version = "1.0.196"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "33c85360c95e7d137454dc81d9a4ed2b8efd8fbe19cee57357b32b9771fccb67"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.48",
+]
+
 [[package]]
 name = "snafu"
 version = "0.7.5"
@@ -626,7 +674,7 @@ dependencies = [
 "heck",
 "proc-macro2",
 "quote",
- "syn",
+ "syn 1.0.109",
 ]

 [[package]]
@@ -693,6 +741,17 @@ dependencies = [
 "unicode-ident",
 ]

+[[package]]
+name = "syn"
+version = "2.0.48"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0f3531638e407dfc0814761abb7c00a5b54992b849452a0646b7f65c9f770f3f"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
 [[package]]
 name = "synopsys-usb-otg"
 version = "0.3.2"
@@ -724,11 +783,12 @@ checksum = "55937e1799185b12863d447f42597ed69d9928686b8d88a1df17376a097d8369"

 [[package]]
 name = "time"
-version = "0.3.30"
+version = "0.3.33"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c4a34ab300f2dee6e562c10a046fc05e358b29f9bf92277f30c3c8d82275f6f5"
+checksum = "00b24b79b7a07f10209f19e683ca1e289d80b1e76ffa8c2b779718566a083679"
 dependencies = [
 "deranged",
+ "num-conv",
 "powerfmt",
 "time-core",
 ]

--- a/Cargo.toml
+++ b/Cargo.toml
 [package]
 name = "cats-mobile-transceiver-mainboard"
-version = "0.2.0"
+version = "0.2.1"
 edition = "2021"
 license = "MIT"

@@ -26,11 +26,13 @@ ham-cats = { git = "https://gitlab.scd31.com/cats/ham-cats" }
 half = { version = "2.3.1", default-features = false }
 # TODO can get rid of some of these features
 nmea = { version = "0.6.0", default-features = false, features = ["VTG", "GGA", "RMC", "GNS", "GLL"] }
-arrayvec = { version = "0.7.4", default-features = false }
+arrayvec = { version = "0.7.4", default-features = false, features = ["serde"] }
 ushell = "0.3.6"
 usbd-serial = "0.1.1"
 usb-device = "0.2.9"
 crc = "3.0.1"
 embedded-storage = "0.2.0"
 num-traits = { version = "0.2.17", default-features = false, features = ["libm"] }
-rand = { version = "0.8", default_features = false, features = ["small_rng"] }
+rand = { version = "0.8", default-features = false, features = ["small_rng"] }
+postcard = "1.0.8"
+serde = { version = "1.0.196", default-features = false, features = ["derive"] }
--- a/README.md
+++ b/README.md
@@ -21,6 +21,18 @@ You may also want to add a comment:
 set comment Hello World!
 ```

+And possibly enable GPS:
+
+```
+set gps receiver
+```
+
+It may also be a good idea to look at all the settings to make sure they're how you want them:
+
+```
+get
+```
+
 Don't forget to enable transmitting and save your settings:

 ```
@@ -49,9 +61,39 @@ The black hole can be configured with `set black_hole lat lon radius_meters`. Fo

 Note that you probably don't want to center your black hole exactly on your house. It may be possible to work out its position based on when exactly you stop transmitting. Instead, you should configure the black hole to overlap with your house, without being centered.

-## Compiling and flashing firmware
+## Updating firmware (Linux)
+
+**NOTE:** Currently, updating the firmware can only be done on Linux. If you don't have a Linux computer, a Raspberry Pi, Virtual Machine, or Live-booted distro can be used.
+
+1. Download the flasher utility from [here](https://gitlab.scd31.com/cats/mobile-transceiver-software/builds/artifacts/master/browse/flasher?job=build-flasher).
+2. Run the utility:
+```bash
+chmod +x flasher-linux
+sudo ./flasher-linux
+```
+3. Follow the instructions on the screen. Afterwards, the board will restart automatically.
+
+## Updating firmware (Mac)
+1. Install dependencies
+```bash
+brew install arm-none-eabi-gcc
+brew install dfu-util
+```
+2. Download the firmware binary from [here](https://gitlab.scd31.com/cats/mobile-transceiver-software/builds/artifacts/master/browse/?job=build)
+3. Put the transceiver into firmware flashing mode:
+    1. Connect the board to your computer via USB
+    2. Hold down the `flash` button
+    3. Momentarily press the `reset` button
+    4. Release the `flash` button
+    5. The red LED will come on, then go off. If it stays on, it means your computer isn’t communicating with the board for some reason. Check your cable!
+4. Flash the firmware:
+```bash
+arm-none-eabi-objcopy -O binary firmware.bin firmware_actual.bin
+/opt/homebrew/bin/dfu-util -l # find serial
+/opt/homebrew/bin/dfu-util --dfuse-address 0x08000000 -S SERIAL_NUMBER_GOES_HERE -a 0 -D firmware_actual.bin
+```

-At the moment, updating the board's firmware requires manually compiling the new firmware and flashing it to the board. The setup for this isn't too bad and requires no specialized hardware.
+## Compiling firmware from source (Linux only)

 ### Environment setup

@@ -68,7 +110,7 @@ cargo install flip-link # needed for building
 cargo install cargo-dfu # needed for flashing
 ```

-Finally, if you're on Linux, you may need to give yourself permission to write to the board.
+Finally, you may need to give yourself permission to write to the board.

 ```bash
 sudo cp udev.rules /etc/udev/rules.d/99-dfu-stm32.rules
@@ -78,7 +120,7 @@ sudo udevadm control --reload-rules && sudo udevadm trigger
 ### Board setup
 1. Connect the board to your computer via USB
 2. Hold down the `flash` button
-3. Press the `reset` button
+3. Momentarily press the `reset` button
 4. Release the `flash` button

 The red LED will come on, then go off. If it stays on, it means your computer isn't communicating with the board for some reason. Check your cable!

--- a/rustfmt.toml
+++ b/rustfmt.toml
+edition = "2021"
--- a/src/config.rs
+++ b/src/config.rs
@@ -3,15 +3,18 @@ use core::fmt::Display;
 use arrayvec::ArrayString;
 use crc::{Crc, CRC_32_ISCSI};
 use embedded_storage::nor_flash::{NorFlash, ReadNorFlash};
+use serde::{Deserialize, Serialize};
 use stm32f4xx_hal::flash::{FlashExt, LockedFlash};

 use crate::geo::distance_km;

-const CONFIG_LEN: usize = 844;
+const DEFAULT_FREQUENCY: u32 = 430_500_000;
+const CONFIG_LEN: usize = 2048;
 const CASTAGNOLI: Crc<u32> = Crc::<u32>::new(&CRC_32_ISCSI);

-#[derive(Clone)]
+#[derive(Clone, Serialize, Deserialize)]
 pub struct Config {
+    pub frequency: Frequency,
    pub callsign: ArrayString<252>,
    pub icon: u16,
    pub ssid: u8,
@@ -59,88 +62,32 @@ impl Config {
        // version
        // allows us to update the config structure in the future
        // while maintaining backwards compatibility
-        buf[0] = 0;
-
-        buf[1..3].copy_from_slice(&self.icon.to_le_bytes());
-        buf[3] = self.ssid;
-        buf[4] = self.max_hops;
-        buf[5..13].copy_from_slice(&self.transmit_period_seconds.to_le_bytes());
-        match self.gps {
-            GpsSetting::Disabled => {
-                buf[13] = 0;
-            }
-
-            GpsSetting::Fixed(lat, lon) => {
-                buf[13] = 1;
-                buf[14..22].copy_from_slice(&lat.to_le_bytes());
-                buf[22..30].copy_from_slice(&lon.to_le_bytes());
-            }
-
-            GpsSetting::Receiver => {
-                buf[13] = 2;
-            }
-        }
-
-        let enable_tx: u8 = self.enable_transmit.into();
-        let enable_digi: u8 = self.enable_digipeating.into();
-        buf[30] = enable_tx | (enable_digi << 1);
-
-        buf[31] = self.callsign.len().try_into().unwrap();
-        buf[32..(32 + self.callsign.len())].copy_from_slice(self.callsign.as_bytes());
-        buf[284..286].copy_from_slice(&u16::try_from(self.comment.len()).unwrap().to_le_bytes());
-        buf[286..(286 + self.comment.len())].copy_from_slice(self.comment.as_bytes());
-
-        self.black_hole
-            .encode((&mut buf[798..823]).try_into().unwrap());
-
-        match self.antenna_height {
-            Maybe::Some(height) => {
-                buf[823] = 1;
-                buf[824] = height;
-            }
-            Maybe::None => buf[823] = 0,
-        }
-
-        match self.antenna_gain {
-            Maybe::Some(gain) => {
-                buf[825] = 1;
-                buf[826..830].copy_from_slice(&gain.to_le_bytes());
-            }
-            Maybe::None => buf[825] = 0,
-        }
+        buf[0] = 1;

-        match self.tx_power {
-            Maybe::Some(power) => {
-                buf[830] = 1;
-                buf[831..835].copy_from_slice(&power.to_le_bytes());
-            }
-            Maybe::None => {
-                buf[830] = 0;
-            }
-        }
-
-        match self.min_voltage {
-            Maybe::Some(v) => {
-                buf[835] = 1;
-                buf[836..840].copy_from_slice(&v.to_le_bytes());
-            }
-            Maybe::None => {
-                buf[835] = 0;
-            }
-        }
+        postcard::to_slice(self, &mut buf[1..]).unwrap();

-        // Checksum
-        let checksum = CASTAGNOLI.checksum(&buf[0..840]);
-        buf[840..844].copy_from_slice(&checksum.to_le_bytes());
+        let checksum = CASTAGNOLI.checksum(&buf[0..2044]);
+        buf[2044..2048].copy_from_slice(&checksum.to_le_bytes());
    }

    fn deserialize(buf: &[u8; CONFIG_LEN]) -> Option<Self> {
        match buf[0] {
            0 => Self::deserialize_v0(buf),
+            1 => Self::deserialize_v1(buf),
            _ => None,
        }
    }

+    fn deserialize_v1(buf: &[u8; CONFIG_LEN]) -> Option<Self> {
+        let expected_checksum = CASTAGNOLI.checksum(&buf[0..2044]);
+        let actual_checksum = u32::from_le_bytes(buf[2044..2048].try_into().unwrap());
+        if expected_checksum != actual_checksum {
+            return None;
+        }
+
+        postcard::from_bytes(&buf[1..2044]).ok()
+    }
+
    fn deserialize_v0(buf: &[u8; CONFIG_LEN]) -> Option<Self> {
        let expected_checksum = CASTAGNOLI.checksum(&buf[0..840]);
        let actual_checksum = u32::from_le_bytes(buf[840..844].try_into().unwrap());
@@ -205,6 +152,7 @@ impl Config {
        };

        Some(Config {
+            frequency: Frequency::default(),
            callsign,
            icon,
            ssid,
@@ -227,6 +175,7 @@ impl Config {
 impl Default for Config {
    fn default() -> Self {
        Config {
+            frequency: Frequency::default(),
            callsign: "N0CALL".try_into().unwrap(),
            icon: 0,
            ssid: 0,
@@ -246,7 +195,7 @@ impl Default for Config {
    }
 }

-#[derive(Copy, Clone)]
+#[derive(Copy, Clone, Serialize, Deserialize)]
 pub enum GpsSetting {
    Disabled,
    Fixed(f64, f64),
@@ -263,7 +212,7 @@ impl Display for GpsSetting {
    }
 }

-#[derive(Copy, Clone)]
+#[derive(Copy, Clone, Serialize, Deserialize)]
 pub enum MaybeBlackHole {
    Some(BlackHoleSetting),
    None,
@@ -281,19 +230,6 @@ impl MaybeBlackHole {
        }
    }

-    fn encode(&self, buf: &mut [u8; 25]) {
-        match self {
-            Self::None => {
-                buf[0] = 0;
-            }
-
-            Self::Some(bhs) => {
-                buf[0] = 1;
-                bhs.encode((&mut buf[1..]).try_into().unwrap());
-            }
-        }
-    }
-
    fn decode(buf: &[u8; 25]) -> Option<Self> {
        match buf[0] {
            0 => Some(Self::None),
@@ -314,7 +250,7 @@ impl Display for MaybeBlackHole {
    }
 }

-#[derive(Copy, Clone)]
+#[derive(Copy, Clone, Serialize, Deserialize)]
 pub struct BlackHoleSetting {
    pub latitude: f64,
    pub longitude: f64,
@@ -322,12 +258,6 @@ pub struct BlackHoleSetting {
 }

 impl BlackHoleSetting {
-    fn encode(&self, buf: &mut [u8; 24]) {
-        buf[0..8].copy_from_slice(&self.latitude.to_le_bytes());
-        buf[8..16].copy_from_slice(&self.longitude.to_le_bytes());
-        buf[16..24].copy_from_slice(&self.radius_meters.to_le_bytes());
-    }
-
    fn decode(buf: &[u8; 24]) -> Self {
        let latitude = f64::from_le_bytes(buf[0..8].try_into().unwrap());
        let longitude = f64::from_le_bytes(buf[8..16].try_into().unwrap());
@@ -352,7 +282,7 @@ impl Display for BlackHoleSetting {
 }

 // Like Option, but local, so we can implement Display on it
-#[derive(Copy, Clone)]
+#[derive(Copy, Clone, Serialize, Deserialize)]
 pub enum Maybe<T> {
    Some(T),
    None,
@@ -378,3 +308,44 @@ impl<T> From<Maybe<T>> for Option<T> {
        }
    }
 }
+
+#[derive(Copy, Clone, Serialize, Deserialize)]
+pub struct Frequency(u32);
+
+impl Frequency {
+    pub fn new(f: u32) -> Option<Self> {
+        if Self::validate_freq(f) {
+            Some(Self(f))
+        } else {
+            None
+        }
+    }
+
+    pub fn new_mhz(f: f64) -> Option<Self> {
+        let hz = u32::try_from((f * 1_000_000.0) as u64).ok()?;
+
+        Self::new(hz)
+    }
+
+    pub fn hz(&self) -> u32 {
+        self.0
+    }
+
+    fn validate_freq(f: u32) -> bool {
+        (420_000_000..=450_000_000).contains(&f)
+    }
+}
+
+impl Default for Frequency {
+    fn default() -> Self {
+        Self(DEFAULT_FREQUENCY)
+    }
+}
+
+impl Display for Frequency {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        let freq_mhz = self.0 as f64 / 1_000_000.0;
+
+        write!(f, "{freq_mhz:.3} MHz")
+    }
+}
--- a/src/gps.rs
+++ b/src/gps.rs
 use nmea::Nmea;

+use crate::{app::monotonics::now, MyInstant};
+
 const MAX_SENTENCE_LEN: usize = 128;

+// If we don't hear from the GPS in a while,
+// lock was lost and we should remove our coords
+const GPS_EXPIRE_SECS: u64 = 10;
+
 #[derive(Copy, Clone)]
 pub struct GpsPos {
    pub latitude: f64,
@@ -17,6 +23,8 @@ pub struct GpsModule {

    sentence: [u8; MAX_SENTENCE_LEN],
    sentence_i: usize,
+
+    last_received: MyInstant,
 }

 impl GpsModule {
@@ -27,6 +35,8 @@ impl GpsModule {

            sentence: [0; MAX_SENTENCE_LEN],
            sentence_i: 0,
+
+            last_received: now(),
        }
    }

@@ -40,6 +50,7 @@ impl GpsModule {
                if let Ok(sentence) = core::str::from_utf8(&self.sentence[..self.sentence_i]) {
                    if self.nmea.parse(sentence).is_ok() {
                        if let Some(pos) = self.raw_pos() {
+                            self.last_received = now();
                            self.cached_pos = Some(pos);
                        }
                    }
@@ -56,17 +67,42 @@ impl GpsModule {
        }
    }

-    pub fn pos(&self) -> Option<GpsPos> {
+    pub fn pos(&mut self) -> Option<GpsPos> {
+        let gps_age_seconds = (now() - self.last_received).to_secs();
+        if gps_age_seconds > GPS_EXPIRE_SECS {
+            return None;
+        }
+
        self.cached_pos
    }

    fn raw_pos(&self) -> Option<GpsPos> {
+        // fallback on cached pos. Otherwise use default values
+        let altitude_meters = self
+            .nmea
+            .altitude
+            .or(self.cached_pos.map(|p| p.altitude_meters))
+            .unwrap_or(0.0);
+
+        let speed_ms = self
+            .nmea
+            .speed_over_ground
+            .map(|x| x * 0.514_444_5)
+            .or(self.cached_pos.map(|p| p.speed_ms))
+            .unwrap_or(0.0);
+
+        let true_course = self
+            .nmea
+            .true_course
+            .or(self.cached_pos.map(|p| p.true_course))
+            .unwrap_or(0.0);
+
        let x = GpsPos {
            latitude: self.nmea.latitude?,
            longitude: self.nmea.longitude?,
-            altitude_meters: self.nmea.altitude?,
-            speed_ms: self.nmea.speed_over_ground? * 0.514_444_5,
-            true_course: self.nmea.true_course?,
+            altitude_meters,
+            speed_ms,
+            true_course,
        };

        Some(x)

--- a/src/main.rs
+++ b/src/main.rs
@@ -12,10 +12,14 @@ mod shell;
 mod status;
 mod voltage;

+use systick_monotonic::fugit::Instant;
+
 pub const MAX_PACKET_LEN: usize = 8191;
 pub const SYS_TICK_FREQ: u32 = 1000;

-#[rtic::app(device = stm32f4xx_hal::pac, peripherals = true, dispatchers = [USART6])]
+pub type MyInstant = Instant<u64, 1, { SYS_TICK_FREQ }>;
+
+#[rtic::app(device = stm32f4xx_hal::pac, peripherals = true, dispatchers = [USART1, USART6])]
 mod app {
    use cortex_m::singleton;
    use hal::{
@@ -56,7 +60,7 @@ mod app {
    const UNDERVOLT_THRES_LEN: u8 = 20; // in # LED blinks

    const HARDWARE_ID: u16 = 0x7c84;
-    const SOFTWARE_ID: u8 = 1;
+    const SOFTWARE_ID: u8 = 2;

    const MODE: Mode = Mode {
        polarity: Polarity::IdleLow,
@@ -187,12 +191,19 @@ mod app {
            hclk: clocks.hclk(),
        };
        unsafe {
+            #[allow(static_mut_refs)]
            USB_BUS.replace(UsbBus::new(usb, &mut EP_MEMORY));
        }

-        let usb_serial = usbd_serial::SerialPort::new(unsafe { USB_BUS.as_ref().unwrap() });
+        let usb_serial = usbd_serial::SerialPort::new(unsafe {
+            #[allow(static_mut_refs)]
+            USB_BUS.as_ref().unwrap()
+        });
        let usb_dev = UsbDeviceBuilder::new(
-            unsafe { USB_BUS.as_ref().unwrap() },
+            unsafe {
+                #[allow(static_mut_refs)]
+                USB_BUS.as_ref().unwrap()
+            },
            UsbVidPid(0x16c0, 0x27dd),
        )
        .manufacturer("cats.radio")
@@ -260,7 +271,7 @@ mod app {
        )
    }

-    #[task(priority = 2, local = [], shared = [red, radio, config, status])]
+    #[task(priority = 3, local = [], shared = [red, radio, config, status])]
    fn radio_tick(mut ctx: radio_tick::Context) {
        (ctx.shared.radio, ctx.shared.config).lock(|r, c| {
            r.as_mut()
@@ -404,7 +415,9 @@ mod app {
                    ctx.local.gps_enable.set_high();
                    ctx.local.green.set_low();
                    ctx.shared.red.lock(|red| red.set_low());
-                    ctx.shared.radio.lock(|r| r.as_mut().map(|x| x.sleep()));
+                    ctx.shared
+                        .radio
+                        .lock(|r| r.as_mut().map(|x| x.sleep().unwrap()));
                }
            }


--- a/src/radio.rs
+++ b/src/radio.rs
 use ham_cats::{buffer::Buffer, identity::Identity, packet::Packet};
 use rand::{rngs::SmallRng, Rng, SeedableRng};
-use rf4463::{config::RADIO_CONFIG_CATS, error::TransferError, Rf4463};
+use rf4463::{
+    config::RADIO_CONFIG_CATS,
+    error::{RfError, TransferError},
+    Rf4463,
+};
 use rtic::Mutex;
 use stm32f4xx_hal::{
    gpio,
@@ -36,8 +40,7 @@ impl<'a> RadioManager<'a> {
    ) -> Option<Self> {
        let mut radio = Rf4463::new(spi, sdn, cs, delay, &mut RADIO_CONFIG_CATS.clone()).ok()?;

-        // sets us up for the default CATS frequency, 430.500 MHz
-        radio.set_channel(20);
+        radio.set_frequency(config.frequency.hz()).ok()?;

        let enable_digipeating = config.enable_digipeating;
        let seed = rand_seed_from_str(&config.callsign) ^ u64::from(config.ssid);
@@ -51,8 +54,8 @@ impl<'a> RadioManager<'a> {
        })
    }

-    pub fn sleep(&mut self) {
-        //self.radio.sleep()
+    pub fn sleep(&mut self) -> Result<(), RfError<spi::Error>> {
+        self.radio.sleep()
    }

    pub fn get_temp(&mut self) -> Option<i8> {

--- a/src/shell.rs
+++ b/src/shell.rs
@@ -10,7 +10,7 @@ use usbd_serial::SerialPort;
 use ushell::{autocomplete::StaticAutocomplete, history::LRUHistory, Input, ShellError, UShell};

 use crate::{
-    config::{BlackHoleSetting, Config, GpsSetting, Maybe, MaybeBlackHole},
+    config::{BlackHoleSetting, Config, Frequency, GpsSetting, Maybe, MaybeBlackHole},
    voltage::VoltMeter,
 };

@@ -19,8 +19,8 @@ type ShellType =

 const SAVE_TEXT: &str =
    "Saved your settings. Remove USB and press the reset button when you're ready.\r\n\
-	 The board won't transmit when USB is attached, even if enable_transmit is true!\r\n\
-	 ";
+     The board won't transmit when USB is attached, even if enable_transmit is true!\r\n\
+     ";

 const HELP_TEXT: &str = concat!(
    "\r\n\
@@ -28,14 +28,14 @@ const HELP_TEXT: &str = concat!(
     Firmware version v",
    env!("CARGO_PKG_VERSION"),
    "\r\n\
-	 Available commands:\r\n\
-	 \r\n\
-	 help                       Display this text\r\n\r\n\
-	 get                        Show the current configuration\r\n\r\n\
-	 set [property] [value]     Update the current configuration\r\n                           For a list of properties, see the `get` command\r\n\r\n\
-	 save                       Save the current settings to flash memory for persistence\r\n\r\n\
-	 volts                      Show the current input voltage. Only reads from the screw terminals - will show ~0V if only connected to USB\r\n\
-	 "
+     Available commands:\r\n\
+     \r\n\
+     help                       Display this text\r\n\r\n\
+     get                        Show the current configuration\r\n\r\n\
+     set [property] [value]     Update the current configuration\r\n                           For a list of properties, see the `get` command\r\n\r\n\
+     save                       Save the current settings to flash memory for persistence\r\n\r\n\
+     volts                      Show the current input voltage. Only reads from the screw terminals - will show ~0V if only connected to USB\r\n\
+     "
 );

 pub struct Shell {
@@ -62,6 +62,7 @@ impl Shell {
                    match cmd {
                        "get" => {
                            let Config {
+                                frequency,
                                callsign,
                                icon,
                                ssid,
@@ -88,27 +89,28 @@ impl Shell {
                            write!(
                                ushell,
                                "\r\n\
-							 callsign           {callsign}\r\n\
-							 ssid               {ssid}\r\n\
-							 icon               {icon}\r\n\
-							 max_hops           {max_hops}\r\n\
-							 comment            {comment}\r\n\
-							 transmit_period    {transmit_period_seconds} (seconds)\r\n\
-							 gps                {gps}\r\n\
-							 black_hole         {black_hole}\r\n\
-							 min_voltage        {min_voltage:.2}\r\n\
-							 enable_transmit    {enable_transmit}\r\n\
-							 enable_digipeating {enable_digipeating}\r\n\
-							 \r\n\
-							 The following settings do not change the behaviour of the transceiver.\r\n\
-							 Instead, they only change the contents of the NodeInfo whisker.\r\n\
-							 Info configuration:\r\n\
-							 antenna_height     {antenna_height:.1} (meters)\r\n\
-							 antenna_gain       {antenna_gain:.1} (dBi)\r\n\
-							 tx_power           {tx_power} (dBm)\r\n\
-							 \r\n\
-							 To change a setting, type `set <property> <value>`\r\n\
-							 For example, `set transmit_period 300`\r\n"
+                             frequency          {frequency}\r\n\
+                             callsign           {callsign}\r\n\
+                             ssid               {ssid}\r\n\
+                             icon               {icon}\r\n\
+                             max_hops           {max_hops}\r\n\
+                             comment            {comment}\r\n\
+                             transmit_period    {transmit_period_seconds} (seconds)\r\n\
+                             gps                {gps}\r\n\
+                             black_hole         {black_hole}\r\n\
+                             min_voltage        {min_voltage:.2}\r\n\
+                             enable_transmit    {enable_transmit}\r\n\
+                             enable_digipeating {enable_digipeating}\r\n\
+                             \r\n\
+                             The following settings do not change the behaviour of the transceiver.\r\n\
+                             Instead, they only change the contents of the NodeInfo whisker.\r\n\
+                             Info configuration:\r\n\
+                             antenna_height     {antenna_height:.1} (meters)\r\n\
+                             antenna_gain       {antenna_gain:.1} (dBi)\r\n\
+                             tx_power           {tx_power} (dBm)\r\n\
+                             \r\n\
+                             To change a setting, type `set <property> <value>`\r\n\
+                             For example, `set transmit_period 300`\r\n"
                            )
                            .ok();
                        }
@@ -116,6 +118,13 @@ impl Shell {
                            let (property, value) = args.split_once(' ').unwrap_or((args, ""));

                            let res = match property {
+                                "frequency" => match parse_frequency(value) {
+                                    Ok(v) => {
+                                        self.config.frequency = v;
+                                        Ok(())
+                                    }
+                                    Err(e) => Err(e),
+                                },
                                "callsign" => {
                                    if value.trim().is_empty() {
                                        Err("Blank callsign is invalid")
@@ -231,9 +240,9 @@ impl Shell {
                            };

                            match res {
-								Ok(()) => write!(ushell, "\r\nOK. Don't forget to save your settings when you're done with `save`!\r\n").ok(),
-								Err(e) => write!(ushell, "\r\nError: {}\r\n", e).ok()
-							};
+                                Ok(()) => write!(ushell, "\r\nOK. Don't forget to save your settings when you're done with `save`!\r\n").ok(),
+                                Err(e) => write!(ushell, "\r\nError: {}\r\n", e).ok()
+                            };
                        }
                        "save" => {
                            write!(ushell, "\r\n").ok();
@@ -261,16 +270,20 @@ impl Shell {
                        }
                        // Used for QA only
                        "quicktest" => {
+                            let comment = ArrayString::from(
+                                "Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula eget dolor. \
+                                 Aenean massa. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. \
+                                 Donec quam felis, ultricies nec, pellentesque eu, pretium quis, sem. Nulla consequat massa quis enim. \
+                                 Donec pede justo, fringilla vel, aliquet nec, vulputate eget, arcu. In enim justo, rhoncus ut, imperdiet a, \
+                                 venenatis vitae, justo. Nullam dictum felis eu pede mollis pretium. Integer tincidunt. Cras dapibu").unwrap();
+
                            self.config = Config {
+                                frequency: Frequency::new(430_450_000).unwrap(),
                                callsign: args.try_into().unwrap(),
                                icon: 0,
                                ssid: 255,
                                max_hops: 0,
-                                comment: ArrayString::from("Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Aenean commodo ligula eget dolor. \
-                                                            Aenean massa. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. \
-                                                            Donec quam felis, ultricies nec, pellentesque eu, pretium quis, sem. Nulla consequat massa quis enim. \
-                                                            Donec pede justo, fringilla vel, aliquet nec, vulputate eget, arcu. In enim justo, rhoncus ut, imperdiet a, \
-                                                            venenatis vitae, justo. Nullam dictum felis eu pede mollis pretium. Integer tincidunt. Cras dapibu").unwrap(),
+                                comment,
                                transmit_period_seconds: 3,
                                gps: GpsSetting::Receiver,
                                enable_transmit: true,
@@ -279,7 +292,7 @@ impl Shell {
                                antenna_height: Maybe::None,
                                antenna_gain: Maybe::None,
                                tx_power: Maybe::Some(30.0),
-								min_voltage: Maybe::Some(9.0),
+                                min_voltage: Maybe::Some(9.0),
                            };
                            self.config.save_to_flash(flash);

@@ -302,6 +315,12 @@ impl Shell {
    }
 }

+fn parse_frequency(val: &str) -> Result<Frequency, &'static str> {
+    const ERR: &str = "Invalid value. Expected a frequency between 420 and 450 MHz.";
+
+    val.parse().ok().and_then(Frequency::new_mhz).ok_or(ERR)
+}
+
 fn parse_arrstring<const N: usize>(val: &str) -> Result<ArrayString<N>, &'static str> {
    match val.try_into() {
        Ok(x) => Ok(x),
@@ -353,9 +372,9 @@ fn parse_maybe_f32(val: &str) -> Result<Maybe<f32>, &'static str> {

 fn parse_gps(val: &str) -> Result<GpsSetting, &'static str> {
    const GENERIC_ERR: &str = "Invalid value. Expected one of the following options:\r\n\
-							   The literal `disabled` (set gps disable) - Do not set GPS data in transmitted packets\r\n\
-							   The literal `receiver` (set gps receiver) - Use a connected GPS module\r\n\
-							   A lat/lon pair (set gps 12.34 56.78) - Use the specified fixed coordinates";
+                               The literal `disabled` (set gps disable) - Do not set GPS data in transmitted packets\r\n\
+                               The literal `receiver` (set gps receiver) - Use a connected GPS module\r\n\
+                               A lat/lon pair (set gps 12.34 56.78) - Use the specified fixed coordinates";

    match val {
        "disabled" => Ok(GpsSetting::Disabled),
@@ -372,8 +391,8 @@ fn parse_gps(val: &str) -> Result<GpsSetting, &'static str> {

 fn parse_black_hole(val: &str) -> Result<MaybeBlackHole, &'static str> {
    const ERR: &str = "Invalid value. Expected `lat lon radius`, where radius is in meters.\r\n\
-					   For example, `set black_hole 12.34 56.78 1000` to exclude 1000m around (12.34, 56.78).\r\n\
-					   Alternatively, clear this setting with `set black_hole none`.";
+                       For example, `set black_hole 12.34 56.78 1000` to exclude 1000m around (12.34, 56.78).\r\n\
+                       Alternatively, clear this setting with `set black_hole none`.";

    if val.trim().eq_ignore_ascii_case("none") {
        return Ok(MaybeBlackHole::None);
No results found