Merge #380

380: Adding data livestream capability r=ryan-summers a=ryan-summers

This PR implements livestream capability for ADC and DAC samples. The current implementation provides a static configuration.

**TODO**
- [x] Clean up documentation
- [x] Implement streaming for `lockin` app
- [x] Test new block-packetization scheme
- [x] Add reference python stream receiver
- [x] Merge #381 first

Co-authored-by: Ryan Summers <ryan.summers@vertigo-designs.com>

Cargo.lock

@@ -38,7 +38,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b9a69a963b70ddacfcd382524f72a4576f359af9334b3bf48a79566590bb8bfa"
 dependencies = [
  "bitrate",
- "cortex-m 0.7.2",
+ "cortex-m 0.6.7",
  "embedded-hal",
 ]
 
@@ -389,9 +389,9 @@ dependencies = [
 
 [[package]]
 name = "managed"
-version = "0.7.2"
+version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c75de51135344a4f8ed3cfe2720dc27736f7711989703a0b43aadf3753c55577"
+checksum = "0ca88d725a0a943b096803bd34e73a4437208b6077654cc4ecb2947a5f91618d"
 
 [[package]]
 name = "matrixmultiply"
@@ -455,9 +455,9 @@ checksum = "546c37ac5d9e56f55e73b677106873d9d9f5190605e41a856503623648488cae"
 
 [[package]]
 name = "ndarray"
-version = "0.15.2"
+version = "0.15.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "02b2e4807aaa21dc6dcc3417e5902dc199c3648043bf27b7af4b202332fe4760"
+checksum = "cc1372704f14bb132a49a6701c2238970a359ee0829fed481b522a63bf25456a"
 dependencies = [
  "matrixmultiply",
  "num-complex",
@@ -743,9 +743,8 @@ dependencies = [
 
 [[package]]
 name = "smoltcp"
-version = "0.7.3"
+version = "0.8.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
+source = "git+https://github.com/smoltcp-rs/smoltcp?branch=master#027f255f904b9b7c4226cfd8b2d31f272ffa5105"
-checksum = "11b5647cc4676e9358e6b15b6536b34e5b413e5ae946a06b3f85e713132bcdfa"
 dependencies = [
  "bitflags",
  "byteorder",
@@ -755,7 +754,7 @@ dependencies = [
 [[package]]
 name = "smoltcp-nal"
 version = "0.1.0"
-source = "git+https://github.com/quartiq/smoltcp-nal.git?rev=5e56576#5e56576fbbc594f0a0e1df9222a20eb35c8e7511"
+source = "git+https://github.com/quartiq/smoltcp-nal.git?rev=5baf55f#5baf55fafbfe2c08d9fe56c836171e9d2fb468e8"
 dependencies = [
  "embedded-nal",
  "heapless 0.7.1",
@@ -804,7 +803,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8b672c837e0ee8158ecc7fce0f9a948dd0693a9c588338e728d14b73307a0b7d"
 dependencies = [
  "bare-metal 0.2.5",
- "cortex-m 0.7.2",
+ "cortex-m 0.6.7",
  "cortex-m-rt",
  "vcell",
 ]
@@ -812,7 +811,7 @@ dependencies = [
 [[package]]
 name = "stm32h7xx-hal"
 version = "0.9.0"
-source = "git+https://github.com/quartiq/stm32h7xx-hal.git?rev=acd47be#acd47beb4b84b4dc46da3a8b68688bc8c5984604"
+source = "git+https://github.com/quartiq/stm32h7xx-hal.git?rev=33aa67d#33aa67d74790cb9f680a4f281b72df0664bcf03c"
 dependencies = [
  "bare-metal 1.0.0",
  "cast",

Cargo.toml

@@ -60,7 +60,7 @@ rev = "70b0eb5"
 features = ["stm32h743v", "rt", "unproven", "ethernet", "quadspi"]
 # version = "0.9.0"
 git = "https://github.com/quartiq/stm32h7xx-hal.git"
-rev = "acd47be"
+rev = "33aa67d"
 
 # link.x section start/end
 [patch.crates-io.cortex-m-rt]
@@ -73,7 +73,7 @@ rev = "2750533"
 
 [dependencies.smoltcp-nal]
 git = "https://github.com/quartiq/smoltcp-nal.git"
-rev = "5e56576"
+rev = "5baf55f"
 
 [dependencies.minimq]
 git = "https://github.com/quartiq/minimq.git"

scripts/stream_throughput.py

@@ -0,0 +1,189 @@
+#!/usr/bin/python3
+"""
+Author: Ryan Summers
+
+Description: Provides a mechanism for measuring Stabilizer stream data throughput.
+"""
+import socket
+import collections
+import struct
+import time
+import logging
+
+# Representation of a single UDP packet transmitted by Stabilizer.
+Packet = collections.namedtuple('Packet', ['index', 'adc', 'dac'])
+
+class Timer:
+    """ A basic timer for measuring elapsed time periods. """
+
+    def __init__(self, period=1.0):
+        """ Create the timer with the provided period. """
+        self.start_time = time.time()
+        self.trigger_time = self.start_time + period
+        self.period = period
+        self.started = False
+
+
+    def is_triggered(self):
+        """ Check if the timer period has elapsed. """
+        now = time.time()
+        return now >= self.trigger_time
+
+
+    def start(self):
+        """ Start the timer. """
+        self.start_time = time.time()
+        self.started = True
+
+
+    def is_started(self):
+        """ Check if the timer has started. """
+        return self.started
+
+
+    def arm(self):
+        """ Arm the timer trigger. """
+        self.trigger_time = time.time() + self.period
+
+
+    def elapsed(self):
+        """ Get the elapsed time since the timer was started. """
+        now = time.time()
+        return now - self.start_time
+
+
+class PacketParser:
+    """ Utilize class used for parsing received UDP data. """
+
+    def __init__(self):
+        """ Initialize the parser. """
+        self.buf = b''
+        self.total_bytes = 0
+
+
+    def ingress(self, data):
+        """ Ingress received UDP data. """
+        self.total_bytes += len(data)
+        self.buf += data
+
+
+    def parse_all_packets(self):
+        """ Parse all received packets from the receive buffer.
+
+        Returns:
+            A list of received Packets.
+        """
+        packets = []
+        while True:
+            new_packets = self._parse()
+            if new_packets:
+                packets += new_packets
+            else:
+                return packets
+
+
+    def _parse(self):
+        """ Attempt to parse packets from the received buffer. """
+        # Attempt to parse a block from the buffer.
+        if len(self.buf) < 4:
+            return None
+
+        start_id, num_blocks, data_size = struct.unpack_from('!HBB', self.buf)
+
+        packet_size = 4 + data_size * num_blocks * 8
+
+        if len(self.buf) < packet_size:
+            return None
+
+        self.buf = self.buf[4:]
+
+        packets = []
+        for offset in range(num_blocks):
+            adcs_dacs = struct.unpack_from(f'!{4 * data_size}H', self.buf)
+            adc = [
+                adcs_dacs[0:data_size],
+                adcs_dacs[data_size:2*data_size],
+            ]
+
+            dac = [
+                adcs_dacs[2*data_size: 3*data_size],
+                adcs_dacs[3*data_size:],
+            ]
+
+            self.buf = self.buf[8*data_size:]
+            packets.append(Packet(start_id + offset, adc, dac))
+
+        return packets
+
+
+def check_index(previous_index, next_index):
+    """ Check if two indices are sequential. """
+    if previous_index == -1:
+        return True
+
+    # Handle index roll-over. Indices are only stored in 16-bit numbers.
+    if next_index < previous_index:
+        next_index += 65536
+
+    expected_index = previous_index + 1
+
+    return next_index == expected_index
+
+
+def main():
+    """ Main program. """
+    connection = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+    connection.bind(("", 1111))
+
+    logging.basicConfig(level=logging.INFO,
+                        format='%(asctime)s.%(msecs)03d %(levelname)-8s %(message)s')
+
+    last_index = -1
+
+    drop_count = 0
+    good_blocks = 0
+
+    timer = Timer()
+    parser = PacketParser()
+
+    while True:
+        # Receive any data over UDP and parse it.
+        data = connection.recv(4096)
+        if data and not timer.is_started():
+            timer.start()
+
+        parser.ingress(data)
+
+        # Handle any received packets.
+        for packet in parser.parse_all_packets():
+
+            # Handle any dropped packets.
+            if not check_index(last_index, packet.index):
+                print(hex(last_index), hex(packet.index))
+                if packet.index < (last_index + 1):
+                    dropped = packet.index + 65536 - (last_index + 1)
+                else:
+                    dropped = packet.index - (last_index + 1)
+
+                drop_count += dropped
+
+            last_index = packet.index
+            good_blocks += 1
+
+        # Report the throughput periodically.
+        if timer.is_triggered():
+            drate = parser.total_bytes * 8 / 1e6 / timer.elapsed()
+
+            print(f'''
+Data Rate:       {drate:.3f} Mbps
+Received Blocks: {good_blocks}
+Dropped blocks:  {drop_count}
+
+Metadata: {parser.total_bytes / 1e6:.3f} MB in {timer.elapsed():.2f} s
+----
+''')
+            timer.arm()
+
+
+if __name__ == '__main__':
+    main()

src/bin/dual-iir.rs

@@ -18,6 +18,7 @@ use stabilizer::{
         DigitalInput0, DigitalInput1, AFE0, AFE1,
     },
     net::{
+        data_stream::{BlockGenerator, StreamTarget},
         miniconf::Miniconf,
         serde::Deserialize,
         telemetry::{Telemetry, TelemetryBuffer},
@@ -37,6 +38,7 @@ pub struct Settings {
     allow_hold: bool,
     force_hold: bool,
     telemetry_period: u16,
+    stream_target: StreamTarget,
 }
 
 impl Default for Settings {
@@ -56,6 +58,8 @@ impl Default for Settings {
             force_hold: false,
             // The default telemetry period in seconds.
             telemetry_period: 10,
+
+            stream_target: StreamTarget::default(),
         }
     }
 }
@@ -68,6 +72,7 @@ const APP: () = {
         adcs: (Adc0Input, Adc1Input),
         dacs: (Dac0Output, Dac1Output),
         network: NetworkUsers<Settings, Telemetry>,
+        generator: BlockGenerator,
 
         settings: Settings,
         telemetry: TelemetryBuffer,
@@ -76,13 +81,13 @@ const APP: () = {
         iir_state: [[iir::Vec5; IIR_CASCADE_LENGTH]; 2],
     }
 
-    #[init(spawn=[telemetry, settings_update])]
+    #[init(spawn=[telemetry, settings_update, ethernet_link])]
     fn init(c: init::Context) -> init::LateResources {
         // Configure the microcontroller
         let (mut stabilizer, _pounder) =
             hardware::setup::setup(c.core, c.device);
 
-        let network = NetworkUsers::new(
+        let mut network = NetworkUsers::new(
             stabilizer.net.stack,
             stabilizer.net.phy,
             stabilizer.cycle_counter,
@@ -90,10 +95,15 @@ const APP: () = {
             stabilizer.net.mac_address,
         );
 
+        let generator = network.enable_streaming();
+
         // Spawn a settings update for default settings.
         c.spawn.settings_update().unwrap();
         c.spawn.telemetry().unwrap();
 
+        // Spawn the ethernet link period check task.
+        c.spawn.ethernet_link().unwrap();
+
         // Enable ADC/DAC events
         stabilizer.adcs.0.start();
         stabilizer.adcs.1.start();
@@ -107,6 +117,7 @@ const APP: () = {
             afes: stabilizer.afes,
             adcs: stabilizer.adcs,
             dacs: stabilizer.dacs,
+            generator,
             network,
             digital_inputs: stabilizer.digital_inputs,
             telemetry: TelemetryBuffer::default(),
@@ -130,7 +141,7 @@ const APP: () = {
     ///
     /// Because the ADC and DAC operate at the same rate, these two constraints actually implement
     /// the same time bounds, meeting one also means the other is also met.
-    #[task(binds=DMA1_STR4, resources=[adcs, digital_inputs, dacs, iir_state, settings, telemetry], priority=2)]
+    #[task(binds=DMA1_STR4, resources=[adcs, digital_inputs, dacs, iir_state, settings, telemetry, generator], priority=2)]
     #[inline(never)]
     #[link_section = ".itcm.process"]
     fn process(mut c: process::Context) {
@@ -141,6 +152,7 @@ const APP: () = {
             ref settings,
             ref mut iir_state,
             ref mut telemetry,
+            ref mut generator,
         } = c.resources;
 
         let digital_inputs = [
@@ -180,6 +192,9 @@ const APP: () = {
                     .last();
             }
 
+            // Stream the data.
+            generator.send(&adc_samples, &dac_samples);
+
             // Update telemetry measurements.
             telemetry.adcs =
                 [AdcCode(adc_samples[0][0]), AdcCode(adc_samples[1][0])];
@@ -214,6 +229,9 @@ const APP: () = {
         // Update AFEs
         c.resources.afes.0.set_gain(settings.afe[0]);
         c.resources.afes.1.set_gain(settings.afe[1]);
+
+        let target = settings.stream_target.into();
+        c.resources.network.direct_stream(target);
     }
 
     #[task(priority = 1, resources=[network, settings, telemetry], schedule=[telemetry])]
@@ -240,6 +258,14 @@ const APP: () = {
             .unwrap();
     }
 
+    #[task(priority = 1, resources=[network], schedule=[ethernet_link])]
+    fn ethernet_link(c: ethernet_link::Context) {
+        c.resources.network.processor.handle_link();
+        c.schedule
+            .ethernet_link(c.scheduled + SystemTimer::ticks_from_secs(1))
+            .unwrap();
+    }
+
     #[task(binds = ETH, priority = 1)]
     fn eth(_: eth::Context) {
         unsafe { hal::ethernet::interrupt_handler() }

src/bin/lockin.rs

@@ -20,6 +20,7 @@ use stabilizer::{
         DigitalInput0, DigitalInput1, AFE0, AFE1,
     },
     net::{
+        data_stream::{BlockGenerator, StreamTarget},
         miniconf::Miniconf,
         serde::Deserialize,
         telemetry::{Telemetry, TelemetryBuffer},
@@ -64,6 +65,8 @@ pub struct Settings {
 
     output_conf: [Conf; 2],
     telemetry_period: u16,
+
+    stream_target: StreamTarget,
 }
 
 impl Default for Settings {
@@ -82,6 +85,8 @@ impl Default for Settings {
             output_conf: [Conf::InPhase, Conf::Quadrature],
             // The default telemetry period in seconds.
             telemetry_period: 10,
+
+            stream_target: StreamTarget::default(),
         }
     }
 }
@@ -96,19 +101,20 @@ const APP: () = {
         settings: Settings,
         telemetry: TelemetryBuffer,
         digital_inputs: (DigitalInput0, DigitalInput1),
+        generator: BlockGenerator,
 
         timestamper: InputStamper,
         pll: RPLL,
         lockin: Lockin<4>,
     }
 
-    #[init(spawn=[settings_update, telemetry])]
+    #[init(spawn=[settings_update, telemetry, ethernet_link])]
     fn init(c: init::Context) -> init::LateResources {
         // Configure the microcontroller
         let (mut stabilizer, _pounder) =
             hardware::setup::setup(c.core, c.device);
 
-        let network = NetworkUsers::new(
+        let mut network = NetworkUsers::new(
             stabilizer.net.stack,
             stabilizer.net.phy,
             stabilizer.cycle_counter,
@@ -116,6 +122,8 @@ const APP: () = {
             stabilizer.net.mac_address,
         );
 
+        let generator = network.enable_streaming();
+
         let settings = Settings::default();
 
         let pll = RPLL::new(
@@ -127,6 +135,9 @@ const APP: () = {
         c.spawn.settings_update().unwrap();
         c.spawn.telemetry().unwrap();
 
+        // Spawn the ethernet link servicing task.
+        c.spawn.ethernet_link().unwrap();
+
         // Enable ADC/DAC events
         stabilizer.adcs.0.start();
         stabilizer.adcs.1.start();
@@ -152,6 +163,7 @@ const APP: () = {
             telemetry: TelemetryBuffer::default(),
 
             settings,
+            generator,
 
             pll,
             lockin: Lockin::default(),
@@ -165,7 +177,7 @@ const APP: () = {
     /// This is an implementation of a externally (DI0) referenced PLL lockin on the ADC0 signal.
     /// It outputs either I/Q or power/phase on DAC0/DAC1. Data is normalized to full scale.
     /// PLL bandwidth, filter bandwidth, slope, and x/y or power/phase post-filters are available.
-    #[task(binds=DMA1_STR4, resources=[adcs, dacs, lockin, timestamper, pll, settings, telemetry], priority=2)]
+    #[task(binds=DMA1_STR4, resources=[adcs, dacs, lockin, timestamper, pll, settings, telemetry, generator], priority=2)]
     #[inline(never)]
     #[link_section = ".itcm.process"]
     fn process(mut c: process::Context) {
@@ -177,6 +189,7 @@ const APP: () = {
             ref mut lockin,
             ref mut pll,
             ref mut timestamper,
+            ref mut generator,
         } = c.resources;
 
         let (reference_phase, reference_frequency) = match settings.lockin_mode
@@ -249,6 +262,10 @@ const APP: () = {
                     *sample = DacCode::from(value as i16).0;
                 }
             }
+
+            // Stream data
+            generator.send(&adc_samples, &dac_samples);
+
             // Update telemetry measurements.
             telemetry.adcs =
                 [AdcCode(adc_samples[0][0]), AdcCode(adc_samples[1][0])];
@@ -282,6 +299,9 @@ const APP: () = {
         c.resources.afes.1.set_gain(settings.afe[1]);
 
         c.resources.settings.lock(|current| *current = *settings);
+
+        let target = settings.stream_target.into();
+        c.resources.network.direct_stream(target);
     }
 
     #[task(priority = 1, resources=[network, digital_inputs, settings, telemetry], schedule=[telemetry])]
@@ -313,6 +333,14 @@ const APP: () = {
             .unwrap();
     }
 
+    #[task(priority = 1, resources=[network], schedule=[ethernet_link])]
+    fn ethernet_link(c: ethernet_link::Context) {
+        c.resources.network.processor.handle_link();
+        c.schedule
+            .ethernet_link(c.scheduled + SystemTimer::ticks_from_secs(1))
+            .unwrap();
+    }
+
     #[task(binds = ETH, priority = 1)]
     fn eth(_: eth::Context) {
         unsafe { hal::ethernet::interrupt_handler() }

src/hardware/setup.rs

@@ -7,9 +7,6 @@ use stm32h7xx_hal::{
     prelude::*,
 };
 
-const NUM_SOCKETS: usize = 4;
-
-use heapless::Vec;
 use smoltcp_nal::smoltcp;
 
 use embedded_hal::digital::v2::{InputPin, OutputPin};
@@ -21,13 +18,18 @@ use super::{
     NetworkStack, AFE0, AFE1,
 };
 
+const NUM_TCP_SOCKETS: usize = 4;
+const NUM_UDP_SOCKETS: usize = 1;
+const NUM_SOCKETS: usize = NUM_UDP_SOCKETS + NUM_TCP_SOCKETS;
+
 pub struct NetStorage {
     pub ip_addrs: [smoltcp::wire::IpCidr; 1],
 
     // Note: There is an additional socket set item required for the DHCP socket.
     pub sockets:
         [Option<smoltcp::socket::SocketSetItem<'static>>; NUM_SOCKETS + 1],
-    pub socket_storage: [SocketStorage; NUM_SOCKETS],
+    pub tcp_socket_storage: [TcpSocketStorage; NUM_TCP_SOCKETS],
+    pub udp_socket_storage: [UdpSocketStorage; NUM_UDP_SOCKETS],
     pub neighbor_cache:
         [Option<(smoltcp::wire::IpAddress, smoltcp::iface::Neighbor)>; 8],
     pub routes_cache:
@@ -39,13 +41,37 @@ pub struct NetStorage {
     pub dhcp_rx_storage: [u8; 600],
 }
 
+pub struct UdpSocketStorage {
+    rx_storage: [u8; 1024],
+    tx_storage: [u8; 2048],
+    tx_metadata:
+        [smoltcp::storage::PacketMetadata<smoltcp::wire::IpEndpoint>; 10],
+    rx_metadata:
+        [smoltcp::storage::PacketMetadata<smoltcp::wire::IpEndpoint>; 10],
+}
+
+impl UdpSocketStorage {
+    const fn new() -> Self {
+        Self {
+            rx_storage: [0; 1024],
+            tx_storage: [0; 2048],
+            tx_metadata: [smoltcp::storage::PacketMetadata::<
+                smoltcp::wire::IpEndpoint,
+            >::EMPTY; 10],
+            rx_metadata: [smoltcp::storage::PacketMetadata::<
+                smoltcp::wire::IpEndpoint,
+            >::EMPTY; 10],
+        }
+    }
+}
+
 #[derive(Copy, Clone)]
-pub struct SocketStorage {
+pub struct TcpSocketStorage {
     rx_storage: [u8; 1024],
     tx_storage: [u8; 1024],
 }
 
-impl SocketStorage {
+impl TcpSocketStorage {
     const fn new() -> Self {
         Self {
             rx_storage: [0; 1024],
@@ -63,8 +89,9 @@ impl NetStorage {
             )],
             neighbor_cache: [None; 8],
             routes_cache: [None; 8],
-            sockets: [None, None, None, None, None],
+            sockets: [None, None, None, None, None, None],
-            socket_storage: [SocketStorage::new(); NUM_SOCKETS],
+            tcp_socket_storage: [TcpSocketStorage::new(); NUM_TCP_SOCKETS],
+            udp_socket_storage: [UdpSocketStorage::new(); NUM_UDP_SOCKETS],
             dhcp_tx_storage: [0; 600],
             dhcp_rx_storage: [0; 600],
             dhcp_rx_metadata: [smoltcp::socket::RawPacketMetadata::EMPTY; 1],
@@ -634,20 +661,18 @@ pub fn setup(
         let neighbor_cache =
             smoltcp::iface::NeighborCache::new(&mut store.neighbor_cache[..]);
 
-        let interface = smoltcp::iface::EthernetInterfaceBuilder::new(eth_dma)
+        let interface = smoltcp::iface::InterfaceBuilder::new(eth_dma)
             .ethernet_addr(mac_addr)
             .neighbor_cache(neighbor_cache)
             .ip_addrs(&mut store.ip_addrs[..])
             .routes(routes)
             .finalize();
 
-        let (mut sockets, handles) = {
+        let sockets = {
             let mut sockets =
                 smoltcp::socket::SocketSet::new(&mut store.sockets[..]);
 
-            let mut handles: Vec<smoltcp::socket::SocketHandle, 64> =
+            for storage in store.tcp_socket_storage[..].iter_mut() {
-                Vec::new();
-            for storage in store.socket_storage.iter_mut() {
                 let tcp_socket = {
                     let rx_buffer = smoltcp::socket::TcpSocketBuffer::new(
                         &mut storage.rx_storage[..],
@@ -658,34 +683,28 @@ pub fn setup(
 
                     smoltcp::socket::TcpSocket::new(rx_buffer, tx_buffer)
                 };
-                let handle = sockets.add(tcp_socket);
+                sockets.add(tcp_socket);
-
-                handles.push(handle).unwrap();
             }
 
-            (sockets, handles)
+            for storage in store.udp_socket_storage[..].iter_mut() {
+                let udp_socket = {
+                    let rx_buffer = smoltcp::socket::UdpSocketBuffer::new(
+                        &mut storage.rx_metadata[..],
+                        &mut storage.rx_storage[..],
+                    );
+                    let tx_buffer = smoltcp::socket::UdpSocketBuffer::new(
+                        &mut storage.tx_metadata[..],
+                        &mut storage.tx_storage[..],
+                    );
+
+                    smoltcp::socket::UdpSocket::new(rx_buffer, tx_buffer)
                 };
+                sockets.add(udp_socket);
+            }
 
-        let dhcp_client = {
+            sockets.add(smoltcp::socket::Dhcpv4Socket::new());
-            let dhcp_rx_buffer = smoltcp::socket::RawSocketBuffer::new(
-                &mut store.dhcp_rx_metadata[..],
-                &mut store.dhcp_rx_storage[..],
-            );
 
-            let dhcp_tx_buffer = smoltcp::socket::RawSocketBuffer::new(
+            sockets
-                &mut store.dhcp_tx_metadata[..],
-                &mut store.dhcp_tx_storage[..],
-            );
-
-            smoltcp::dhcp::Dhcpv4Client::new(
-                &mut sockets,
-                dhcp_rx_buffer,
-                dhcp_tx_buffer,
-                // Smoltcp indicates that an instant with a negative time is indicative that time is
-                // not yet available. We can't get the current instant yet, so indicate an invalid
-                // time value.
-                smoltcp::time::Instant::from_millis(-1),
-            )
         };
 
         let random_seed = {
@@ -696,12 +715,7 @@ pub fn setup(
             data
         };
 
-        let mut stack = smoltcp_nal::NetworkStack::new(
+        let mut stack = smoltcp_nal::NetworkStack::new(interface, sockets);
-            interface,
-            sockets,
-            &handles,
-            Some(dhcp_client),
-        );
 
         stack.seed_random_port(&random_seed);
 

src/net/data_stream.rs

@@ -0,0 +1,353 @@
+///! Stabilizer data stream capabilities
+///!
+///! # Design
+///! Stabilizer data streamining utilizes UDP packets to send live data streams at high throughput.
+///! Packets are always sent in a best-effort fashion, and data may be dropped. Each packet contains
+///! an identifier that can be used to detect any dropped data.
+///!
+///! The current implementation utilizes an single-producer, single-consumer queue to send data
+///! between a high priority task and the UDP transmitter.
+///!
+///! A "batch" of data is defined to be a single item in the SPSC queue sent to the UDP transmitter
+///! thread. The transmitter thread then serializes as many sequential "batches" into a single UDP
+///! packet as possible. The UDP packet is also given a header indicating the starting batch
+///! sequence number and the number of batches present. If the UDP transmitter encounters a
+///! non-sequential batch, it does not enqueue it into the packet and instead transmits any staged
+///! data. The non-sequential batch is then transmitted in a new UDP packet. This method allows a
+///! receiver to detect dropped batches (e.g. due to processing overhead).
+use heapless::spsc::{Consumer, Producer, Queue};
+use miniconf::MiniconfAtomic;
+use serde::Deserialize;
+use smoltcp_nal::embedded_nal::{IpAddr, Ipv4Addr, SocketAddr, UdpClientStack};
+
+use super::NetworkReference;
+use crate::hardware::design_parameters::SAMPLE_BUFFER_SIZE;
+
+// The number of data blocks that we will buffer in the queue.
+const BLOCK_BUFFER_SIZE: usize = 30;
+
+// A factor that data may be subsampled at.
+const SUBSAMPLE_RATE: usize = 1;
+
+/// Represents the destination for the UDP stream to send data to.
+#[derive(Copy, Clone, Debug, MiniconfAtomic, Deserialize)]
+pub struct StreamTarget {
+    pub ip: [u8; 4],
+    pub port: u16,
+}
+
+impl Default for StreamTarget {
+    fn default() -> Self {
+        Self {
+            ip: [0; 4],
+            port: 0,
+        }
+    }
+}
+
+impl From<StreamTarget> for SocketAddr {
+    fn from(target: StreamTarget) -> SocketAddr {
+        SocketAddr::new(
+            IpAddr::V4(Ipv4Addr::new(
+                target.ip[0],
+                target.ip[1],
+                target.ip[2],
+                target.ip[3],
+            )),
+            target.port,
+        )
+    }
+}
+
+/// A basic "batch" of data.
+// Note: In the future, the stream may be generic over this type.
+#[derive(Debug, Copy, Clone)]
+pub struct AdcDacData {
+    block_id: u16,
+    adcs: [[u16; SAMPLE_BUFFER_SIZE]; 2],
+    dacs: [[u16; SAMPLE_BUFFER_SIZE]; 2],
+}
+
+/// Configure streaming on a device.
+///
+/// # Args
+/// * `stack` - A reference to the shared network stack.
+///
+/// # Returns
+/// (generator, stream) where `generator` can be used to enqueue "batches" for transmission. The
+/// `stream` is the logically consumer (UDP transmitter) of the enqueued data.
+pub fn setup_streaming(
+    stack: NetworkReference,
+) -> (BlockGenerator, DataStream) {
+    let queue = cortex_m::singleton!(: Queue<AdcDacData, BLOCK_BUFFER_SIZE> = Queue::new()).unwrap();
+
+    let (producer, consumer) = queue.split();
+
+    let generator = BlockGenerator::new(producer);
+
+    let stream = DataStream::new(stack, consumer);
+
+    (generator, stream)
+}
+
+/// The data generator for a stream.
+pub struct BlockGenerator {
+    queue: Producer<'static, AdcDacData, BLOCK_BUFFER_SIZE>,
+    current_id: u16,
+}
+
+impl BlockGenerator {
+    /// Construct a new generator.
+    /// # Args
+    /// * `queue` - The producer portion of the SPSC queue to enqueue data into.
+    ///
+    /// # Returns
+    /// The generator to use.
+    fn new(queue: Producer<'static, AdcDacData, BLOCK_BUFFER_SIZE>) -> Self {
+        Self {
+            queue,
+            current_id: 0,
+        }
+    }
+
+    /// Schedule data to be sent by the generator.
+    ///
+    /// # Note
+    /// If no space is available, the data batch may be silently dropped.
+    ///
+    /// # Args
+    /// * `adcs` - The ADC data to transmit.
+    /// * `dacs` - The DAC data to transmit.
+    pub fn send(
+        &mut self,
+        adcs: &[&mut [u16; SAMPLE_BUFFER_SIZE]; 2],
+        dacs: &[&mut [u16; SAMPLE_BUFFER_SIZE]; 2],
+    ) {
+        let block = AdcDacData {
+            block_id: self.current_id,
+            adcs: [*adcs[0], *adcs[1]],
+            dacs: [*dacs[0], *dacs[1]],
+        };
+
+        self.current_id = self.current_id.wrapping_add(1);
+        self.queue.enqueue(block).ok();
+    }
+}
+
+/// Represents a single UDP packet sent by the stream.
+///
+/// # Packet Format
+/// All data is sent in network-endian format. The format is as follows
+///
+/// Header:
+/// [0..2]: Start block ID (u16)
+/// [2..3]: Num Blocks present (u8) <N>
+/// [3..4]: Batch Size (u8) <BS>
+///
+/// Following the header, batches are added sequentially. Each batch takes the form of:
+/// [<BS>*0..<BS>*2]: ADC0
+/// [<BS>*2..<BS>*4]: ADC1
+/// [<BS>*4..<BS>*6]: DAC0
+/// [<BS>*6..<BS>*8]: DAC1
+struct DataPacket<'a> {
+    buf: &'a mut [u8],
+    subsample_rate: usize,
+    start_id: Option<u16>,
+    num_blocks: u8,
+    write_index: usize,
+}
+
+impl<'a> DataPacket<'a> {
+    /// Construct a new packet.
+    ///
+    /// # Args
+    /// * `buf` - The location to serialize the data packet into.
+    /// * `subsample_rate` - The factor at which to subsample data from batches.
+    pub fn new(buf: &'a mut [u8], subsample_rate: usize) -> Self {
+        Self {
+            buf,
+            start_id: None,
+            num_blocks: 0,
+            subsample_rate,
+            write_index: 4,
+        }
+    }
+
+    /// Add a batch of data to the packet.
+    ///
+    /// # Note
+    /// Serialization occurs as the packet is added.
+    ///
+    /// # Args
+    /// * `batch` - The batch to add to the packet.
+    pub fn add_batch(&mut self, batch: &AdcDacData) -> Result<(), ()> {
+        // Check that the block is sequential.
+        if let Some(id) = &self.start_id {
+            if batch.block_id != id.wrapping_add(self.num_blocks.into()) {
+                return Err(());
+            }
+        } else {
+            // Otherwise, this is the first block. Record the strt ID.
+            self.start_id = Some(batch.block_id);
+        }
+
+        // Check that there is space for the block.
+        let block_size_bytes = SAMPLE_BUFFER_SIZE / self.subsample_rate * 4 * 2;
+        if self.buf.len() - self.get_packet_size() < block_size_bytes {
+            return Err(());
+        }
+
+        // Copy the samples into the buffer.
+        for device in &[batch.adcs, batch.dacs] {
+            for channel in device {
+                for sample in channel.iter().step_by(self.subsample_rate) {
+                    self.buf[self.write_index..self.write_index + 2]
+                        .copy_from_slice(&sample.to_be_bytes());
+                    self.write_index += 2;
+                }
+            }
+        }
+
+        self.num_blocks += 1;
+
+        Ok(())
+    }
+
+    fn get_packet_size(&self) -> usize {
+        let header_length = 4;
+        let block_sample_size = SAMPLE_BUFFER_SIZE / self.subsample_rate;
+        let block_size_bytes = block_sample_size * 2 * 4;
+
+        block_size_bytes * self.num_blocks as usize + header_length
+    }
+
+    /// Complete the packet and prepare it for transmission.
+    ///
+    /// # Returns
+    /// The size of the packet. The user should utilize the original buffer provided for packet
+    /// construction to access the packet.
+    pub fn finish(self) -> usize {
+        let block_sample_size = SAMPLE_BUFFER_SIZE / self.subsample_rate;
+
+        // Write the header into the block.
+        self.buf[0..2].copy_from_slice(&self.start_id.unwrap().to_be_bytes());
+        self.buf[2] = self.num_blocks;
+        self.buf[3] = block_sample_size as u8;
+
+        // Return the length of the packet to transmit.
+        self.get_packet_size()
+    }
+}
+
+/// The "consumer" portion of the data stream.
+///
+/// # Note
+/// This is responsible for consuming data and sending it over UDP.
+pub struct DataStream {
+    stack: NetworkReference,
+    socket: Option<<NetworkReference as UdpClientStack>::UdpSocket>,
+    queue: Consumer<'static, AdcDacData, BLOCK_BUFFER_SIZE>,
+    remote: SocketAddr,
+    buffer: [u8; 1024],
+}
+
+impl DataStream {
+    /// Construct a new data streamer.
+    ///
+    /// # Args
+    /// * `stack` - A reference to the shared network stack.
+    /// * `consumer` - The read side of the queue containing data to transmit.
+    fn new(
+        stack: NetworkReference,
+        consumer: Consumer<'static, AdcDacData, BLOCK_BUFFER_SIZE>,
+    ) -> Self {
+        Self {
+            stack,
+            socket: None,
+            remote: StreamTarget::default().into(),
+            queue: consumer,
+            buffer: [0; 1024],
+        }
+    }
+
+    fn close(&mut self) {
+        // Note(unwrap): We guarantee that the socket is available above.
+        let socket = self.socket.take().unwrap();
+        self.stack.close(socket).unwrap();
+    }
+
+    fn open(&mut self, remote: SocketAddr) -> Result<(), ()> {
+        if self.socket.is_some() {
+            self.close();
+        }
+
+        // If the remote address is unspecified, just close the existing socket.
+        if remote.ip().is_unspecified() {
+            if self.socket.is_some() {
+                self.close();
+            }
+
+            return Err(());
+        }
+
+        let mut socket = self.stack.socket().map_err(|_| ())?;
+
+        // Note(unwrap): We only connect with a new socket, so it is guaranteed to not already be
+        // bound.
+        self.stack.connect(&mut socket, remote).unwrap();
+
+        self.socket.replace(socket);
+
+        Ok(())
+    }
+
+    /// Configure the remote endpoint of the stream.
+    ///
+    /// # Args
+    /// * `remote` - The destination to send stream data to.
+    pub fn set_remote(&mut self, remote: SocketAddr) {
+        // If the remote is identical to what we already have, do nothing.
+        if remote == self.remote {
+            return;
+        }
+
+        // Open the new remote connection.
+        self.open(remote).ok();
+        self.remote = remote;
+    }
+
+    /// Process any data for transmission.
+    pub fn process(&mut self) {
+        // If there's no socket available, try to connect to our remote.
+        if self.socket.is_none() {
+            // If we can't open the socket (e.g. we do not have an IP address yet), clear data from
+            // the queue.
+            if self.open(self.remote).is_err() {
+                while self.queue.ready() {
+                    self.queue.dequeue();
+                }
+                return;
+            }
+        }
+
+        if self.queue.ready() {
+            // Dequeue data from the queue into a larger block structure.
+            let mut packet = DataPacket::new(&mut self.buffer, SUBSAMPLE_RATE);
+            while self.queue.ready() {
+                // Note(unwrap): We check above that the queue is ready before calling this.
+                if packet.add_batch(self.queue.peek().unwrap()).is_err() {
+                    // If we cannot add another batch, break out of the loop and send the packet.
+                    break;
+                }
+
+                // Remove the batch that we just added.
+                self.queue.dequeue();
+            }
+
+            // Transmit the data block.
+            let mut handle = self.socket.as_mut().unwrap();
+            let size = packet.finish();
+            self.stack.send(&mut handle, &self.buffer[..size]).ok();
+        }
+    }
+}

src/net/mod.rs

@@ -9,6 +9,7 @@ pub use heapless;
 pub use miniconf;
 pub use serde;
 
+pub mod data_stream;
 pub mod messages;
 pub mod miniconf_client;
 pub mod network_processor;
@@ -16,6 +17,7 @@ pub mod shared;
 pub mod telemetry;
 
 use crate::hardware::{cycle_counter::CycleCounter, EthernetPhy, NetworkStack};
+use data_stream::{BlockGenerator, DataStream};
 use messages::{MqttMessage, SettingsResponse};
 use miniconf_client::MiniconfClient;
 use network_processor::NetworkProcessor;
@@ -26,6 +28,7 @@ use core::fmt::Write;
 use heapless::String;
 use miniconf::Miniconf;
 use serde::Serialize;
+use smoltcp_nal::embedded_nal::SocketAddr;
 
 pub type NetworkReference = shared::NetworkStackProxy<'static, NetworkStack>;
 
@@ -45,6 +48,8 @@ pub enum NetworkState {
 pub struct NetworkUsers<S: Default + Clone + Miniconf, T: Serialize> {
     pub miniconf: MiniconfClient<S>,
     pub processor: NetworkProcessor,
+    stream: DataStream,
+    generator: Option<BlockGenerator>,
     pub telemetry: TelemetryClient<T>,
 }
 
@@ -95,10 +100,30 @@ where
             &prefix,
         );
 
+        let (generator, stream) =
+            data_stream::setup_streaming(stack_manager.acquire_stack());
+
         NetworkUsers {
             miniconf: settings,
             processor,
             telemetry,
+            stream,
+            generator: Some(generator),
+        }
+    }
+
+    /// Enable live data streaming.
+    pub fn enable_streaming(&mut self) -> BlockGenerator {
+        self.generator.take().unwrap()
+    }
+
+    /// Direct the stream to the provided remote target.
+    ///
+    /// # Args
+    /// * `remote` - The destination for the streamed data.
+    pub fn direct_stream(&mut self, remote: SocketAddr) {
+        if self.generator.is_none() {
+            self.stream.set_remote(remote);
         }
     }
 
@@ -107,15 +132,20 @@ where
     /// # Returns
     /// An indication if any of the network users indicated a state change.
     pub fn update(&mut self) -> NetworkState {
+        // Update the MQTT clients.
+        self.telemetry.update();
+
+        // Update the data stream.
+        if self.generator.is_none() {
+            self.stream.process();
+        }
+
         // Poll for incoming data.
         let poll_result = match self.processor.update() {
             UpdateState::NoChange => NetworkState::NoChange,
             UpdateState::Updated => NetworkState::Updated,
         };
 
-        // Update the MQTT clients.
-        self.telemetry.update();
-
         match self.miniconf.update() {
             UpdateState::Updated => NetworkState::SettingsChanged,
             UpdateState::NoChange => poll_result,

src/net/network_processor.rs

@@ -37,6 +37,27 @@ impl NetworkProcessor {
         }
     }
 
+    /// Handle ethernet link connection status.
+    ///
+    /// # Note
+    /// This may take non-trivial amounts of time to communicate with the PHY. As such, this should
+    /// only be called as often as necessary (e.g. once per second or so).
+    pub fn handle_link(&mut self) {
+        // If the PHY indicates there's no more ethernet link, reset the DHCP server in the network
+        // stack.
+        match self.phy.poll_link() {
+            true => self.network_was_reset = false,
+
+            // Only reset the network stack once per link reconnection. This prevents us from
+            // sending an excessive number of DHCP requests.
+            false if !self.network_was_reset => {
+                self.network_was_reset = true;
+                self.stack.lock(|stack| stack.handle_link_reset());
+            }
+            _ => {}
+        };
+    }
+
     /// Process and update the state of the network.
     ///
     /// # Note
@@ -52,24 +73,7 @@ impl NetworkProcessor {
         let result = match self.stack.lock(|stack| stack.poll(now)) {
             Ok(true) => UpdateState::Updated,
             Ok(false) => UpdateState::NoChange,
-            Err(err) => {
+            Err(_) => UpdateState::Updated,
-                log::info!("Network error: {:?}", err);
-                UpdateState::Updated
-            }
-        };
-
-        // If the PHY indicates there's no more ethernet link, reset the DHCP server in the network
-        // stack.
-        match self.phy.poll_link() {
-            true => self.network_was_reset = false,
-
-            // Only reset the network stack once per link reconnection. This prevents us from
-            // sending an excessive number of DHCP requests.
-            false if !self.network_was_reset => {
-                self.network_was_reset = true;
-                self.stack.lock(|stack| stack.handle_link_reset());
-            }
-            _ => {}
         };
 
         result

src/net/shared.rs

@@ -69,6 +69,21 @@ where
     forward! {close(socket: S::TcpSocket) -> Result<(), S::Error>}
 }
 
+impl<'a, S> embedded_nal::UdpClientStack for NetworkStackProxy<'a, S>
+where
+    S: embedded_nal::UdpClientStack,
+{
+    type UdpSocket = S::UdpSocket;
+    type Error = S::Error;
+
+    forward! {socket() -> Result<S::UdpSocket, S::Error>}
+    forward! {connect(socket: &mut S::UdpSocket, remote: embedded_nal::SocketAddr) -> Result<(), S::Error>}
+
+    forward! {send(socket: &mut S::UdpSocket, buffer: &[u8]) -> embedded_nal::nb::Result<(), S::Error>}
+    forward! {receive(socket: &mut S::UdpSocket, buffer: &mut [u8]) -> embedded_nal::nb::Result<(usize, embedded_nal::SocketAddr), S::Error>}
+    forward! {close(socket: S::UdpSocket) -> Result<(), S::Error>}
+}
+
 impl NetworkManager {
     /// Construct a new manager for a shared network stack
     ///