N! T! P!

Cargo.lock

@@ -125,6 +125,15 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
+[[package]]
+name = "chrono"
+version = "0.4.38"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a21f936df1771bf62b77f047b726c4625ff2e8aa607c01ec06e5a05bd8463401"
+dependencies = [
+ "num-traits",
+]
+
 [[package]]
 name = "codespan-reporting"
 version = "0.11.1"
@@ -191,7 +200,7 @@ checksum = "7a81dae078cea95a014a339291cec439d2f232ebe854a9d672b796c6afafa9b7"
 [[package]]
 name = "cyw43"
 version = "0.2.0"
-source = "git+https://github.com/embassy-rs/embassy.git#c84495ef2eb99580fea5392b2b3aff5ad66043a0"
+source = "git+https://github.com/embassy-rs/embassy.git#4f08d5bc5ff0f765198665b1f37b6372f43b8567"
 dependencies = [
  "cortex-m",
  "cortex-m-rt",
@@ -208,7 +217,7 @@ dependencies = [
 [[package]]
 name = "cyw43-pio"
 version = "0.2.0"
-source = "git+https://github.com/embassy-rs/embassy.git#c84495ef2eb99580fea5392b2b3aff5ad66043a0"
+source = "git+https://github.com/embassy-rs/embassy.git#4f08d5bc5ff0f765198665b1f37b6372f43b8567"
 dependencies = [
  "cyw43",
  "embassy-rp",
@@ -303,7 +312,7 @@ checksum = "60b1af1c220855b6ceac025d3f6ecdd2b7c4894bfe9cd9bda4fbb4bc7c0d4cf0"
 [[package]]
 name = "embassy-embedded-hal"
 version = "0.2.0"
-source = "git+https://github.com/embassy-rs/embassy.git#c84495ef2eb99580fea5392b2b3aff5ad66043a0"
+source = "git+https://github.com/embassy-rs/embassy.git#4f08d5bc5ff0f765198665b1f37b6372f43b8567"
 dependencies = [
  "embassy-futures",
  "embassy-sync",
@@ -319,7 +328,7 @@ dependencies = [
 [[package]]
 name = "embassy-executor"
 version = "0.6.0"
-source = "git+https://github.com/embassy-rs/embassy.git#c84495ef2eb99580fea5392b2b3aff5ad66043a0"
+source = "git+https://github.com/embassy-rs/embassy.git#4f08d5bc5ff0f765198665b1f37b6372f43b8567"
 dependencies = [
  "cortex-m",
  "critical-section",
@@ -332,7 +341,7 @@ dependencies = [
 [[package]]
 name = "embassy-executor-macros"
 version = "0.5.0"
-source = "git+https://github.com/embassy-rs/embassy.git#c84495ef2eb99580fea5392b2b3aff5ad66043a0"
+source = "git+https://github.com/embassy-rs/embassy.git#4f08d5bc5ff0f765198665b1f37b6372f43b8567"
 dependencies = [
  "darling",
  "proc-macro2",
@@ -343,12 +352,12 @@ dependencies = [
 [[package]]
 name = "embassy-futures"
 version = "0.1.1"
-source = "git+https://github.com/embassy-rs/embassy.git#c84495ef2eb99580fea5392b2b3aff5ad66043a0"
+source = "git+https://github.com/embassy-rs/embassy.git#4f08d5bc5ff0f765198665b1f37b6372f43b8567"
 
 [[package]]
 name = "embassy-hal-internal"
 version = "0.2.0"
-source = "git+https://github.com/embassy-rs/embassy.git#c84495ef2eb99580fea5392b2b3aff5ad66043a0"
+source = "git+https://github.com/embassy-rs/embassy.git#4f08d5bc5ff0f765198665b1f37b6372f43b8567"
 dependencies = [
  "cortex-m",
  "critical-section",
@@ -358,7 +367,7 @@ dependencies = [
 [[package]]
 name = "embassy-net"
 version = "0.4.0"
-source = "git+https://github.com/embassy-rs/embassy.git#c84495ef2eb99580fea5392b2b3aff5ad66043a0"
+source = "git+https://github.com/embassy-rs/embassy.git#4f08d5bc5ff0f765198665b1f37b6372f43b8567"
 dependencies = [
  "document-features",
  "embassy-net-driver",
@@ -374,12 +383,12 @@ dependencies = [
 [[package]]
 name = "embassy-net-driver"
 version = "0.2.0"
-source = "git+https://github.com/embassy-rs/embassy.git#c84495ef2eb99580fea5392b2b3aff5ad66043a0"
+source = "git+https://github.com/embassy-rs/embassy.git#4f08d5bc5ff0f765198665b1f37b6372f43b8567"
 
 [[package]]
 name = "embassy-net-driver-channel"
 version = "0.3.0"
-source = "git+https://github.com/embassy-rs/embassy.git#c84495ef2eb99580fea5392b2b3aff5ad66043a0"
+source = "git+https://github.com/embassy-rs/embassy.git#4f08d5bc5ff0f765198665b1f37b6372f43b8567"
 dependencies = [
  "embassy-futures",
  "embassy-net-driver",
@@ -389,7 +398,7 @@ dependencies = [
 [[package]]
 name = "embassy-rp"
 version = "0.2.0"
-source = "git+https://github.com/embassy-rs/embassy.git#c84495ef2eb99580fea5392b2b3aff5ad66043a0"
+source = "git+https://github.com/embassy-rs/embassy.git#4f08d5bc5ff0f765198665b1f37b6372f43b8567"
 dependencies = [
  "atomic-polyfill",
  "cfg-if",
@@ -426,7 +435,7 @@ dependencies = [
 [[package]]
 name = "embassy-sync"
 version = "0.6.0"
-source = "git+https://github.com/embassy-rs/embassy.git#c84495ef2eb99580fea5392b2b3aff5ad66043a0"
+source = "git+https://github.com/embassy-rs/embassy.git#4f08d5bc5ff0f765198665b1f37b6372f43b8567"
 dependencies = [
  "cfg-if",
  "critical-section",
@@ -438,7 +447,7 @@ dependencies = [
 [[package]]
 name = "embassy-time"
 version = "0.3.2"
-source = "git+https://github.com/embassy-rs/embassy.git#c84495ef2eb99580fea5392b2b3aff5ad66043a0"
+source = "git+https://github.com/embassy-rs/embassy.git#4f08d5bc5ff0f765198665b1f37b6372f43b8567"
 dependencies = [
  "cfg-if",
  "critical-section",
@@ -455,7 +464,7 @@ dependencies = [
 [[package]]
 name = "embassy-time-driver"
 version = "0.1.0"
-source = "git+https://github.com/embassy-rs/embassy.git#c84495ef2eb99580fea5392b2b3aff5ad66043a0"
+source = "git+https://github.com/embassy-rs/embassy.git#4f08d5bc5ff0f765198665b1f37b6372f43b8567"
 dependencies = [
  "document-features",
 ]
@@ -463,12 +472,12 @@ dependencies = [
 [[package]]
 name = "embassy-time-queue-driver"
 version = "0.1.0"
-source = "git+https://github.com/embassy-rs/embassy.git#c84495ef2eb99580fea5392b2b3aff5ad66043a0"
+source = "git+https://github.com/embassy-rs/embassy.git#4f08d5bc5ff0f765198665b1f37b6372f43b8567"
 
 [[package]]
 name = "embassy-usb"
 version = "0.3.0"
-source = "git+https://github.com/embassy-rs/embassy.git#c84495ef2eb99580fea5392b2b3aff5ad66043a0"
+source = "git+https://github.com/embassy-rs/embassy.git#4f08d5bc5ff0f765198665b1f37b6372f43b8567"
 dependencies = [
  "embassy-futures",
  "embassy-net-driver-channel",
@@ -482,12 +491,12 @@ dependencies = [
 [[package]]
 name = "embassy-usb-driver"
 version = "0.1.0"
-source = "git+https://github.com/embassy-rs/embassy.git#c84495ef2eb99580fea5392b2b3aff5ad66043a0"
+source = "git+https://github.com/embassy-rs/embassy.git#4f08d5bc5ff0f765198665b1f37b6372f43b8567"
 
 [[package]]
 name = "embassy-usb-logger"
 version = "0.2.0"
-source = "git+https://github.com/embassy-rs/embassy.git#c84495ef2eb99580fea5392b2b3aff5ad66043a0"
+source = "git+https://github.com/embassy-rs/embassy.git#4f08d5bc5ff0f765198665b1f37b6372f43b8567"
 dependencies = [
  "embassy-futures",
  "embassy-sync",
@@ -1001,15 +1010,18 @@ dependencies = [
 name = "picow"
 version = "0.1.0"
 dependencies = [
+ "chrono",
  "cortex-m-rt",
  "cyw43",
  "cyw43-pio",
  "embassy-executor",
  "embassy-net",
  "embassy-rp",
+ "embassy-sync",
  "embassy-time",
  "embassy-usb-logger",
  "log",
+ "no-std-net",
  "panic-halt",
  "portable-atomic",
  "rand",
@@ -1236,9 +1248,9 @@ dependencies = [
 
 [[package]]
 name = "rustversion"
-version = "1.0.17"
+version = "1.0.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "955d28af4278de8121b7ebeb796b6a45735dc01436d898801014aced2773a3d6"
+checksum = "0e819f2bc632f285be6d7cd36e25940d45b2391dd6d9b939e79de557f7014248"
 
 [[package]]
 name = "ryu"

Cargo.toml

@@ -9,19 +9,22 @@ serde = { version = "*", features = ["derive"] }
 serde_yaml = "*"
 
 [dependencies]
+chrono = { version = "*", default-features = false}
 cortex-m-rt = "*"
 cyw43 = { git = "https://github.com/embassy-rs/embassy.git" }
 cyw43-pio = { git = "https://github.com/embassy-rs/embassy.git" }
 embassy-executor = { git = "https://github.com/embassy-rs/embassy.git", features = ["arch-cortex-m", "executor-interrupt", "executor-thread", "integrated-timers", "nightly"] }
-embassy-net = { git = "https://github.com/embassy-rs/embassy.git", features = ["tcp", "udp", "raw", "dhcpv4", "dhcpv4-hostname", "dns", "proto-ipv4", "multicast"] }
+embassy-net = { git = "https://github.com/embassy-rs/embassy.git", features = ["raw", "dhcpv4", "dhcpv4-hostname", "dns", "multicast", "proto-ipv4", "proto-ipv6", "tcp", "udp" ] }
-embassy-rp = { git = "https://github.com/embassy-rs/embassy.git", features = ["critical-section-impl", "time-driver", "rp2040"] }
+embassy-rp = { git = "https://github.com/embassy-rs/embassy.git", features = ["critical-section-impl", "rp2040", "time-driver" ] }
+embassy-sync = { git = "https://github.com/embassy-rs/embassy.git" }
 embassy-time = { git = "https://github.com/embassy-rs/embassy.git" }
 embassy-usb-logger = { git = "https://github.com/embassy-rs/embassy.git" }
 log = "*"
+no-std-net = "*"
 panic-halt = "*"
 portable-atomic = { version = "*", features = ["critical-section"] }
 rand = { version = "*", default-features = false }
-sntpc = { version = "*", default-features = false }
+sntpc = { version = "*", default-features = false, features = ["async"] }
 static_cell = "*"
 
 [profile.release]

flake.lock

@@ -2,11 +2,11 @@
   "nodes": {
     "crane": {
       "locked": {
-        "lastModified": 1728344376,
+        "lastModified": 1728776144,
-        "narHash": "sha256-lxTce2XE6mfJH8Zk6yBbqsbu9/jpwdymbSH5cCbiVOA=",
+        "narHash": "sha256-fROVjMcKRoGHofDm8dY3uDUtCMwUICh/KjBFQnuBzfg=",
         "owner": "ipetkov",
         "repo": "crane",
-        "rev": "fd86b78f5f35f712c72147427b1eb81a9bd55d0b",
+        "rev": "f876e3d905b922502f031aeec1a84490122254b7",
         "type": "github"
       },
       "original": {
@@ -21,11 +21,11 @@
         "rust-analyzer-src": "rust-analyzer-src"
       },
       "locked": {
-        "lastModified": 1728628307,
+        "lastModified": 1728887700,
-        "narHash": "sha256-GRMRHZyU+R0RqKPFFgi7BBMDIRFPnHaAhOIxlqyvbZQ=",
+        "narHash": "sha256-i+WCARuldFmXlNW6XlEYiL8UGMzjdg5lMQ9gpACQL/A=",
         "owner": "nix-community",
         "repo": "fenix",
-        "rev": "b0a014d5b9dba793ebc205bcf12a93b5f6a4c66c",
+        "rev": "bcf74e45d5a818fe3aadf5cb3099189770e18579",
         "type": "github"
       },
       "original": {
@@ -95,11 +95,11 @@
     "rust-analyzer-src": {
       "flake": false,
       "locked": {
-        "lastModified": 1728505432,
+        "lastModified": 1728719115,
-        "narHash": "sha256-QFPMazeiGLo7AGy4RREmTgko0Quch/toMVKhGUjDEeo=",
+        "narHash": "sha256-SLcHmKzkIuahBbSCWr2gzu6bXo6wF12JP4myDzH1CvQ=",
         "owner": "rust-lang",
         "repo": "rust-analyzer",
-        "rev": "0fb804acb375b02a3beeaceeb75b71969ef37b15",
+        "rev": "d7628c0a8b95cadefe89d9a45f9be5ee4898c6b1",
         "type": "github"
       },
       "original": {

flake.nix

@@ -18,7 +18,7 @@
       fenixPkgs = fenix.packages.${system};
       fenixToolchain = fenixPkgs.fromToolchainFile {
         dir = ./.;
-        sha256 = "sha256-HAFn+jo7K/dwbCKRHNXQU+x9b+8LJ8xlQGL/tE0rNlE=";
+        sha256 = "sha256-xN1aESBFCg2dq0LYOHWtU0FtIwkswFbmMoC1GoWCz9c=";
       };
       craneLib = (crane.mkLib pkgs).overrideToolchain fenixToolchain;
     in {

src/main.rs

@@ -2,16 +2,17 @@
 #![no_std]
 #![no_main]
 
-mod picow_time;
+mod time;
 
 extern crate panic_halt;
 
+use chrono::DateTime;
 use cyw43::JoinOptions;
 use cyw43_pio::PioSpi;
 use embassy_executor::Spawner;
 use embassy_net::{
     dns::{DnsQueryType, DnsSocket},
-    Config, DhcpConfig, IpAddress, StackResources,
+    Config, DhcpConfig, IpAddress, Stack, StackResources,
 };
 use embassy_rp::{
     bind_interrupts,
@@ -21,17 +22,24 @@ use embassy_rp::{
     pio::{self, Pio},
     usb::{self, Driver},
 };
+use embassy_sync::{blocking_mutex::raw::CriticalSectionRawMutex, signal::Signal};
 use embassy_time::Timer;
 use log::info;
-use picow_time::PicowUDPBuffer;
+use no_std_net::{IpAddr, Ipv4Addr, SocketAddr};
 use rand::RngCore;
+use sntpc::{async_impl::get_time, NtpContext};
 use static_cell::StaticCell;
+use time::{PicowClock, PicowTimestampGenerator, PicowUDPBuffer};
 
+const DNS_WAIT_SECOND: u64 = 1 << 3;
 const HOSTNAME: &str = "picow";
 const NTP_ENDPOINT: &str = "time.google.com";
-const WAIT_SECOND: u64 = 7;
+const NTP_PORT: u16 = 123;
+const NTP_WAIT_SECOND: u64 = 1 << 6;
+const TIMER_WAIT_SECOND: u64 = 1 << 1;
 const WIRELESS_CREDENTIALS: &[(&str, &str)] =
     &include!(concat!(env!("OUT_DIR"), "/wireless-credentials.rs"));
+const WIRELESS_SCAN_WAIT_SECOND: u64 = 1 << 3;
 
 bind_interrupts!(struct Irqs {
     PIO0_IRQ_0 => pio::InterruptHandler<PIO0>;
@@ -50,6 +58,124 @@ async fn network_task(
     network_runner.run().await;
 }
 
+#[embassy_executor::task]
+async fn ntp_task(
+    clock: &'static PicowClock,
+    network_stack: Stack<'static>,
+    offline_signal: &'static Signal<CriticalSectionRawMutex, ()>,
+) -> ! {
+    // dns client
+    let dns_client = DnsSocket::new(network_stack);
+
+    loop {
+        // wait for network stack
+        info!("Wait for network setup");
+        network_stack.wait_config_up().await;
+        network_stack.wait_link_up().await;
+        info!("Successfully setup network stack");
+        info!("Network configuration: {:?}", network_stack.config_v4());
+
+        let socket_address = match dns_client.query(NTP_ENDPOINT, DnsQueryType::A).await {
+            Ok(address) => match address.first() {
+                Some(IpAddress::Ipv4(ipv4)) => {
+                    let octets = ipv4.octets();
+                    SocketAddr::new(
+                        IpAddr::V4(Ipv4Addr::new(octets[0], octets[1], octets[2], octets[3])),
+                        NTP_PORT,
+                    )
+                }
+                _ => {
+                    info!("DNS A record lookup returned no IPv4 address: {NTP_ENDPOINT}",);
+                    Timer::after_secs(DNS_WAIT_SECOND).await;
+                    continue;
+                }
+            },
+            Err(error) => {
+                info!("DNS A record lookup for {NTP_ENDPOINT} returned error: {error:?}",);
+                Timer::after_secs(DNS_WAIT_SECOND).await;
+                continue;
+            }
+        };
+
+        info!("NTP endpoint identified for {NTP_ENDPOINT}: {socket_address}");
+
+        loop {
+            // udp client
+            let mut udp_buffer = PicowUDPBuffer::default();
+            let udp_client = udp_buffer.socket(network_stack, NTP_PORT);
+            let ntp_context = NtpContext::new(PicowTimestampGenerator::from_clock(clock).await);
+            match get_time(socket_address, udp_client, ntp_context).await {
+                Ok(result) => {
+                    if let Some(now) = DateTime::from_timestamp(result.sec() as i64, 0) {
+                        clock.set_time(now).await;
+                        info!("Calibrated system clock with NTP time: {now}");
+                    } else {
+                        info!("Invalid NTP result: {result:?}");
+                    }
+                }
+                Err(error) => {
+                    info!("Failed to run NTP protocol: {error:?}");
+                    offline_signal.signal(());
+                    break;
+                }
+            }
+            Timer::after_secs(NTP_WAIT_SECOND).await;
+        }
+    }
+}
+
+#[embassy_executor::task]
+async fn online_task(
+    offline_signal: &'static Signal<CriticalSectionRawMutex, ()>,
+    mut wireless_control: cyw43::Control<'static>,
+) -> ! {
+    loop {
+        // search and join wireless network
+        for (ssid, password) in WIRELESS_CREDENTIALS.iter().cycle() {
+            info!("Search for wireless network: {ssid}");
+            if wireless_control
+                .join(ssid, JoinOptions::new(password.as_bytes()))
+                .await
+                .is_ok()
+            {
+                info!("Successfully joined wireless network: {ssid}");
+                break;
+            } else if ssid
+                == &WIRELESS_CREDENTIALS
+                    .last()
+                    .expect("The list of wireless credentials should not be empty")
+                    .0
+            {
+                info!("Unable to join any wireless network with provided credentials");
+                info!("Sleep for {WIRELESS_SCAN_WAIT_SECOND} seconds before rescan");
+                Timer::after_secs(WIRELESS_SCAN_WAIT_SECOND).await;
+            }
+        }
+
+        // turn on led for connected wireless
+        wireless_control.gpio_set(0, true).await;
+
+        // wait for offline signal
+        offline_signal.wait().await;
+        info!("Network is down");
+
+        // disconnect wireless
+        info!("Reset wireless");
+        wireless_control.leave().await;
+
+        // turn off led for disconnected network
+        wireless_control.gpio_set(0, false).await;
+    }
+}
+
+#[embassy_executor::task]
+async fn timer_task(clock: &'static PicowClock) -> ! {
+    loop {
+        info!("The current time is: {}", clock.now().await);
+        Timer::after_secs(TIMER_WAIT_SECOND).await;
+    }
+}
+
 #[embassy_executor::task]
 async fn wireless_task(
     wireless_runner: cyw43::Runner<'static, Output<'static>, PioSpi<'static, PIO0, 0, DMA_CH0>>,
@@ -58,7 +184,11 @@ async fn wireless_task(
 }
 
 #[embassy_executor::main]
-async fn main(spawner: Spawner) -> ! {
+async fn main(spawner: Spawner) {
+    // system clock
+    static CLOCK: StaticCell<PicowClock> = StaticCell::new();
+    let clock = CLOCK.init(PicowClock::new());
+
     // hardware abstraction layer
     let hal = embassy_rp::init(Default::default());
 
@@ -126,73 +256,27 @@ async fn main(spawner: Spawner) -> ! {
         RoscRng.next_u64(),
     );
 
+    // offline signal
+    static OFFLINE_SIGNAL: StaticCell<Signal<CriticalSectionRawMutex, ()>> = StaticCell::new();
+    let offline_signal = OFFLINE_SIGNAL.init(Signal::new());
+
+    // spawn online task
+    spawner
+        .spawn(online_task(offline_signal, wireless_control))
+        .expect("Online task should not fail to spawn");
+
     // spawn network task
     spawner
         .spawn(network_task(network_runner))
         .expect("Network task should not fail to spawn");
 
-    // search and join wireless network
+    // span ntp task
-    for (ssid, password) in WIRELESS_CREDENTIALS.iter().cycle() {
+    spawner
-        info!("Searching for wireless network: {ssid}");
+        .spawn(ntp_task(clock, network_stack, offline_signal))
-        if let Ok(_) = wireless_control
+        .expect("NTP task should not fail to spawn");
-            .join(ssid, JoinOptions::new(password.as_bytes()))
-            .await
-        {
-            info!("Successfully joined wireless network: {ssid}");
-            break;
-        } else if ssid
-            == &WIRELESS_CREDENTIALS
-                .last()
-                .expect("The list of wireless credentials should not be empty")
-                .0
-        {
-            info!("Unable to join any wireless network with provided credentials");
-            info!("Sleep for {WAIT_SECOND} seconds before rescan");
-            Timer::after_secs(WAIT_SECOND).await;
-        }
-    }
 
-    // wait for network stack
+    // spawn timer task
-    info!("Wait for network setup");
+    spawner
-    network_stack.wait_config_up().await;
+        .spawn(timer_task(clock))
-    network_stack.wait_link_up().await;
+        .expect("Timer task should not fail to spawn");
-    info!("Successfully setup network stack");
-    info!("Network configuration: {:?}", network_stack.config_v4());
-
-    // turn on led to indicate network connection
-    wireless_control.gpio_set(0, true).await;
-
-    // dns client
-    let dns_client = DnsSocket::new(network_stack);
-
-    // udp client
-    // let mut udp_buffer = PicowUDPBuffer::default();
-    // let udp_client = udp_buffer.socket(network_stack);
-
-    loop {
-        let ntp_ipv4 = match dns_client.query(NTP_ENDPOINT, DnsQueryType::A).await {
-            Ok(address) => match address.first() {
-                Some(IpAddress::Ipv4(ipv4)) => ipv4.octets(),
-                None => {
-                    info!(
-                        "DNS A record lookup returned no IPv4 address: {}",
-                        NTP_ENDPOINT
-                    );
-                    continue;
-                }
-            },
-            Err(error) => {
-                info!(
-                    "DNS A record lookup returned error: {}, {:?}",
-                    NTP_ENDPOINT, error
-                );
-                continue;
-            }
-        };
-        info!(
-            "Resolved IPv4 address for {}: {}.{}.{}.{}",
-            NTP_ENDPOINT, ntp_ipv4[0], ntp_ipv4[1], ntp_ipv4[1], ntp_ipv4[3]
-        );
-        Timer::after_secs(WAIT_SECOND).await;
-    }
 }

src/picow_time.rs

@@ -1,67 +0,0 @@
-use embassy_net::{
-    udp::{PacketMetadata, UdpSocket},
-    Stack,
-};
-use embassy_time::{Duration, Instant};
-use sntpc::NtpTimestampGenerator;
-
-const UDP_BUFFER_SIZE_BYTE: usize = 1 << 12;
-const UDP_METADATA_SIZE: usize = 1 << 3;
-
-#[derive(Copy, Clone)]
-pub struct PicowTimestampGenerator {
-    duration: Duration,
-}
-
-impl Default for PicowTimestampGenerator {
-    fn default() -> Self {
-        Self {
-            duration: Instant::now().duration_since(Instant::MIN),
-        }
-    }
-}
-
-impl NtpTimestampGenerator for PicowTimestampGenerator {
-    fn init(&mut self) {
-        self.duration = Instant::now().duration_since(Instant::MIN);
-    }
-
-    fn timestamp_sec(&self) -> u64 {
-        self.duration.as_secs()
-    }
-
-    fn timestamp_subsec_micros(&self) -> u32 {
-        (self.duration.as_micros() % 1000000) as u32
-    }
-}
-
-#[derive(Debug)]
-pub struct PicowUDPBuffer {
-    receive_buffer: [u8; UDP_BUFFER_SIZE_BYTE],
-    receive_metadata: [PacketMetadata; UDP_METADATA_SIZE],
-    transmit_buffer: [u8; UDP_BUFFER_SIZE_BYTE],
-    transmit_metadata: [PacketMetadata; UDP_METADATA_SIZE],
-}
-
-impl Default for PicowUDPBuffer {
-    fn default() -> Self {
-        Self {
-            receive_buffer: [0; UDP_BUFFER_SIZE_BYTE],
-            receive_metadata: [PacketMetadata::EMPTY; UDP_METADATA_SIZE],
-            transmit_buffer: [0; UDP_BUFFER_SIZE_BYTE],
-            transmit_metadata: [PacketMetadata::EMPTY; UDP_METADATA_SIZE],
-        }
-    }
-}
-
-impl PicowUDPBuffer {
-    pub fn socket<'me>(&'me mut self, network_stack: Stack<'me>) -> UdpSocket<'me> {
-        UdpSocket::new(
-            network_stack,
-            &mut self.receive_metadata,
-            &mut self.receive_buffer,
-            &mut self.transmit_metadata,
-            &mut self.transmit_buffer,
-        )
-    }
-}

src/time.rs

@@ -0,0 +1,181 @@
+use core::fmt;
+
+use chrono::{DateTime, Duration, Utc};
+use embassy_net::{
+    udp::{PacketMetadata, UdpSocket},
+    IpAddress, IpEndpoint, Stack,
+};
+use embassy_sync::{blocking_mutex::raw::CriticalSectionRawMutex, mutex::Mutex};
+use embassy_time::Instant;
+use no_std_net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr, ToSocketAddrs};
+use sntpc::{async_impl::NtpUdpSocket, NtpTimestampGenerator};
+
+const UDP_BUFFER_SIZE_BYTE: usize = 1 << 12;
+const UDP_METADATA_SIZE: usize = 1 << 4;
+
+pub struct PicowClock {
+    startup_timestamp: Mutex<CriticalSectionRawMutex, DateTime<Utc>>,
+}
+
+impl PicowClock {
+    pub fn new() -> Self {
+        Self {
+            startup_timestamp: Mutex::new(DateTime::UNIX_EPOCH),
+        }
+    }
+
+    pub async fn now(&self) -> DateTime<Utc> {
+        *self.startup_timestamp.lock().await
+            + Duration::microseconds(Instant::now().as_micros() as i64)
+    }
+
+    pub async fn set_time(&self, now: DateTime<Utc>) {
+        if let Some(corrected_startup_timestamp) =
+            now.checked_sub_signed(Duration::microseconds(Instant::now().as_micros() as i64))
+        {
+            *self.startup_timestamp.lock().await = corrected_startup_timestamp;
+        }
+    }
+}
+
+#[derive(Clone, Copy)]
+pub struct PicowTimestampGenerator {
+    now: DateTime<Utc>,
+}
+
+impl NtpTimestampGenerator for PicowTimestampGenerator {
+    fn init(&mut self) {}
+
+    fn timestamp_sec(&self) -> u64 {
+        self.now.timestamp() as u64
+    }
+
+    fn timestamp_subsec_micros(&self) -> u32 {
+        self.now.timestamp_subsec_micros()
+    }
+}
+
+impl PicowTimestampGenerator {
+    pub async fn from_clock(clock: &PicowClock) -> Self {
+        Self {
+            now: clock.now().await,
+        }
+    }
+}
+
+pub struct PicowUDPSocket<'me> {
+    socket: UdpSocket<'me>,
+}
+
+impl fmt::Debug for PicowUDPSocket<'_> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("PicowUDPSocket")
+            .field("socket", &self.socket.endpoint())
+            .finish()
+    }
+}
+
+impl<'me> NtpUdpSocket for PicowUDPSocket<'me> {
+    async fn send_to<T: ToSocketAddrs + Send>(&self, buf: &[u8], addr: T) -> sntpc::Result<usize> {
+        use sntpc::Error::*;
+        let socket_address = addr
+            .to_socket_addrs()
+            .map_err(|_| AddressResolve)?
+            .next()
+            .ok_or(AddressResolve)?;
+
+        // TODO: Simplify conversion once no-std-net is deprecated
+        let endpoint = IpEndpoint::new(
+            match socket_address.ip() {
+                IpAddr::V4(ipv4) => {
+                    let octets = ipv4.octets();
+                    IpAddress::v4(octets[0], octets[1], octets[2], octets[3])
+                }
+                IpAddr::V6(ipv6) => {
+                    let segments = ipv6.segments();
+                    IpAddress::v6(
+                        segments[0],
+                        segments[1],
+                        segments[2],
+                        segments[3],
+                        segments[4],
+                        segments[5],
+                        segments[6],
+                        segments[7],
+                    )
+                }
+            },
+            socket_address.port(),
+        );
+        self.socket
+            .send_to(buf, endpoint)
+            .await
+            .map_err(|_| Network)?;
+        Ok(buf.len())
+    }
+
+    async fn recv_from(&self, buf: &mut [u8]) -> sntpc::Result<(usize, SocketAddr)> {
+        use sntpc::Error::*;
+        let (size, metadata) = self.socket.recv_from(buf).await.map_err(|_| Network)?;
+        Ok((
+            size,
+            SocketAddr::new(
+                // TODO: Simplify conversion once no-std-net is deprecated
+                match metadata.endpoint.addr {
+                    IpAddress::Ipv4(ipv4) => {
+                        let octets = ipv4.octets();
+                        IpAddr::V4(Ipv4Addr::new(octets[0], octets[1], octets[2], octets[3]))
+                    }
+                    IpAddress::Ipv6(ipv6) => {
+                        let segments = ipv6.segments();
+                        IpAddr::V6(Ipv6Addr::new(
+                            segments[0],
+                            segments[1],
+                            segments[2],
+                            segments[3],
+                            segments[4],
+                            segments[5],
+                            segments[6],
+                            segments[7],
+                        ))
+                    }
+                },
+                metadata.endpoint.port,
+            ),
+        ))
+    }
+}
+
+pub struct PicowUDPBuffer {
+    receive_buffer: [u8; UDP_BUFFER_SIZE_BYTE],
+    receive_metadata: [PacketMetadata; UDP_METADATA_SIZE],
+    transmit_buffer: [u8; UDP_BUFFER_SIZE_BYTE],
+    transmit_metadata: [PacketMetadata; UDP_METADATA_SIZE],
+}
+
+impl Default for PicowUDPBuffer {
+    fn default() -> Self {
+        Self {
+            receive_buffer: [0; UDP_BUFFER_SIZE_BYTE],
+            receive_metadata: [PacketMetadata::EMPTY; UDP_METADATA_SIZE],
+            transmit_buffer: [0; UDP_BUFFER_SIZE_BYTE],
+            transmit_metadata: [PacketMetadata::EMPTY; UDP_METADATA_SIZE],
+        }
+    }
+}
+
+impl PicowUDPBuffer {
+    pub fn socket<'me>(&'me mut self, network_stack: Stack<'me>, port: u16) -> PicowUDPSocket<'me> {
+        let mut socket = UdpSocket::new(
+            network_stack,
+            &mut self.receive_metadata,
+            &mut self.receive_buffer,
+            &mut self.transmit_metadata,
+            &mut self.transmit_buffer,
+        );
+        socket
+            .bind(port)
+            .expect("UDP socket should be able to bind to local port");
+        PicowUDPSocket { socket }
+    }
+}