README: Proofread fan control documentation

Put SocketState initialisation logic in new. This avoids using an unsafe
and unnerving MaybeUninit::uninit().assume_init() to initialise an
array, which the compiler yells at since it causes undefined behavior.

Cargo.lock

@@ -327,10 +327,10 @@ dependencies = [
 ]
 
 [[package]]
-name = "panic-abort"
-version = "0.3.2"
+name = "panic-halt"
+version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4e20e6499bbbc412f280b04a42346b356c6fa0753d5fd22b7bd752ff34c778ee"
+checksum = "de96540e0ebde571dc55c73d60ef407c653844e6f9a1e2fdbd40c07b9252d812"
 
 [[package]]
 name = "panic-semihosting"
@@ -563,7 +563,7 @@ dependencies = [
  "nb 1.0.0",
  "nom",
  "num-traits",
- "panic-abort",
+ "panic-halt",
  "panic-semihosting",
  "serde",
  "serde-json-core",

Cargo.toml

@@ -7,14 +7,14 @@ authors = ["Astro <astro@spaceboyz.net>"]
 version = "0.0.0"
 keywords = ["thermostat", "laser", "physics"]
 repository = "https://git.m-labs.hk/M-Labs/thermostat"
-edition = "2018"
+edition = "2021"
 
 [package.metadata.docs.rs]
 features = []
 default-target = "thumbv7em-none-eabihf"
 
 [dependencies]
-panic-abort = "0.3"
+panic-halt = "0.2"
 panic-semihosting = { version = "0.5", optional = true }
 log = "0.4"
 bare-metal = "1"

README.md

@@ -29,7 +29,7 @@ Alternatively, you can install the Rust toolchain without Nix using rustup; see
 
 Connect SWDIO/SWCLK/RST/GND to a programmer such as ST-Link v2.1. Run OpenOCD:
 ```shell
-openocd -f interface/stlink-v2-1.cfg -f target/stm32f4x.cfg
+openocd -f interface/stlink.cfg -f target/stm32f4x.cfg
 ```
 
 You may need to power up the programmer before powering the device.
@@ -64,7 +64,7 @@ On a Windows machine install [st.com](https://st.com) DfuSe USB device firmware
 
 ### OpenOCD
 ```shell
-openocd -f interface/stlink-v2-1.cfg -f target/stm32f4x.cfg -c "program target/thumbv7em-none-eabihf/release/thermostat verify reset;exit"
+openocd -f interface/stlink.cfg -f target/stm32f4x.cfg -c "program target/thumbv7em-none-eabihf/release/thermostat verify reset;exit"
 ```
 
 ## Network
@@ -264,7 +264,6 @@ with the following keys.
 | `temperature`  | Degrees Celsius | Steinhart-Hart conversion result derived from `sens` |
 | `pid_engaged`  | Boolean         | `true` if in closed-loop mode                        |
 | `i_set`        | Amperes         | TEC output current                                   |
-| `vref`         | Volts           | MAX1968 VREF (1.5 V)                                 |
 | `dac_value`    | Volts           | AD5680 output derived from `i_set`                   |
 | `dac_feedback` | Volts           | ADC measurement of the AD5680 output                 |
 | `i_tec`        | Volts           | MAX1968 TEC current monitor                          |
@@ -278,12 +277,11 @@ The thermostat implements a PID control loop for each of the TEC channels, more
 
 ## Fan control
 
-Fan control is available for thermostat revisions with an integrated fan system. Five commands are available for this purpose:
+Fan control commands are available for thermostat revisions with an integrated fan system:
 1. `fan` - show fan stats: `fan_pwm`, `abs_max_tec_i`, `auto_mode`, `k_a`, `k_b`, `k_c`.
-2. `fan auto` - enable auto speed controller mode, which correlates with fan curve `fcurve`.
-3. `fan <value>` - set the fan power with the value from `1` to `100` and disable auto mode. There is no way to disable the fan.
+2. `fan auto` - enable auto speed controller mode, where fan speed is controlled by the fan curve `fcurve`.
+3. `fan <value>` - set the fan power with the value from `1` to `100` and disable auto mode. There is no way to completely disable the fan.
 Please note that power doesn't correlate with the actual speed linearly.
-4. `fcurve <a> <b> <c>` - set coefficients of the controlling curve `a*x^2 + b*x + c`, where `x` is `abs_max_tec_i/MAX_TEC_I`, 
-i.e. receives values from 0 to 1 linearly tied to the maximum current. The controlling curve should produce values from 0 to 1,
-as below and beyond values would be substituted by 0 and 1 respectively.
-5. `fcurve default` - restore fan curve settings to defaults: `a = 1.0, b = 0.0, c = 0.0`.
+4. `fcurve <a> <b> <c>` - set coefficients of the controlling curve `a*x^2 + b*x + c`, where `x` is `abs_max_tec_i/MAX_TEC_I`, a normalized value in range [0,1],
+i.e. the (linear) proportion of current output capacity used, on the channel with the largest current flow. The controlling curve is also clamped to [0,1].
+5. `fcurve default` - restore fan curve coefficients to defaults: `a = 1.0, b = 0.0, c = 0.0`.

flake.nix

@@ -8,8 +8,8 @@
     let
       pkgs = import nixpkgs { system = "x86_64-linux"; overlays = [ (import mozilla-overlay) ]; };
       rustManifest = pkgs.fetchurl {
-        url = "https://static.rust-lang.org/dist/2021-10-26/channel-rust-nightly.toml";
-        sha256 = "sha256-1hLbypXA+nuH7o3AHCokzSBZAvQxvef4x9+XxO3aBao=";
+        url = "https://static.rust-lang.org/dist/2022-12-15/channel-rust-stable.toml";
+        hash = "sha256-S7epLlflwt0d1GZP44u5Xosgf6dRrmr8xxC+Ml2Pq7c=";
       };
 
       targets = [
@@ -22,12 +22,12 @@
           inherit targets;
           extensions = ["rust-src"];
         };
-      rust = rustChannelOfTargets "nightly" null targets;
+      rust = rustChannelOfTargets "stable" null targets;
       rustPlatform = pkgs.recurseIntoAttrs (pkgs.makeRustPlatform {
         rustc = rust;
         cargo = rust;
       });
-      thermostat = rustPlatform.buildRustPackage rec {
+      thermostat = rustPlatform.buildRustPackage {
         name = "thermostat";
         version = "0.0.0";
 
@@ -67,8 +67,7 @@
       devShell.x86_64-linux = pkgs.mkShell {
         name = "thermostat-dev-shell";
         buildInputs = with pkgs; [
-          rustc cargo
-          openocd dfu-util
+          rust openocd dfu-util
           ] ++ (with python3Packages; [
             numpy matplotlib
           ]);

src/channels.rs

@@ -1,3 +1,4 @@
+use core::cmp::max_by;
 use heapless::{consts::U2, Vec};
 use serde::{Serialize, Serializer};
 use smoltcp::time::Instant;
@@ -524,14 +525,9 @@ impl Channels {
     }
 
     pub fn current_abs_max_tec_i(&mut self) -> ElectricCurrent {
-        let mut max_abs_current = ElectricCurrent::new::<ampere>(0.0);
-        for channel in 0..CHANNELS {
-            let channel_abs_current = self.get_tec_i(channel).abs();
-            if channel_abs_current > max_abs_current {
-                max_abs_current = channel_abs_current;
-            }
-        }
-        max_abs_current
+        max_by(self.get_tec_i(0).abs(),
+               self.get_tec_i(1).abs(),
+               |a, b| a.partial_cmp(b).unwrap_or(core::cmp::Ordering::Equal))
     }
 }
 

src/command_handler.rs

@@ -13,7 +13,6 @@ use super::{
         PwmPin, 
         ShParameter
     },
-    leds::Leds,
     ad7172,
     CHANNEL_CONFIG_KEY,
     channels::{
@@ -176,13 +175,13 @@ impl Handler {
         Ok(Handler::Handled)
     }
 
-    fn engage_pid (socket: &mut TcpSocket, channels: &mut Channels, leds: &mut Leds, channel: usize) -> Result<Handler, Error> {
+    fn engage_pid (socket: &mut TcpSocket, channels: &mut Channels, channel: usize) -> Result<Handler, Error> {
         channels.channel_state(channel).pid_engaged = true;
         send_line(socket, b"{}");
         Ok(Handler::Handled)
     }
 
-    fn set_pwm (socket: &mut TcpSocket, channels: &mut Channels, leds: &mut Leds, channel: usize, pin: PwmPin, value: f64) -> Result<Handler, Error> {
+    fn set_pwm (socket: &mut TcpSocket, channels: &mut Channels, channel: usize, pin: PwmPin, value: f64) -> Result<Handler, Error> {
         match pin {
             PwmPin::ISet => {
                 channels.channel_state(channel).pid_engaged = false;
@@ -413,7 +412,7 @@ impl Handler {
         }
     }
 
-    pub fn handle_command(command: Command, socket: &mut TcpSocket, channels: &mut Channels, session: &Session, leds: &mut Leds, store: &mut FlashStore, ipv4_config: &mut Ipv4Config, fan_ctrl: &mut FanCtrl, hwrev: HWRev) -> Result<Self, Error> {
+    pub fn handle_command(command: Command, socket: &mut TcpSocket, channels: &mut Channels, session: &Session, store: &mut FlashStore, ipv4_config: &mut Ipv4Config, fan_ctrl: &mut FanCtrl, hwrev: HWRev) -> Result<Self, Error> {
         match command {
             Command::Quit => Ok(Handler::CloseSocket),
             Command::Reporting(_reporting) => Handler::reporting(socket),            
@@ -424,8 +423,8 @@ impl Handler {
             Command::Show(ShowCommand::SteinhartHart) => Handler::show_steinhart_hart(socket, channels),
             Command::Show(ShowCommand::PostFilter) => Handler::show_post_filter(socket, channels),
             Command::Show(ShowCommand::Ipv4) => Handler::show_ipv4(socket, ipv4_config),
-            Command::PwmPid { channel } => Handler::engage_pid(socket, channels, leds, channel),
-            Command::Pwm { channel, pin, value } => Handler::set_pwm(socket, channels, leds, channel, pin, value),
+            Command::PwmPid { channel } => Handler::engage_pid(socket, channels, channel),
+            Command::Pwm { channel, pin, value } => Handler::set_pwm(socket, channels, channel, pin, value),
             Command::CenterPoint { channel, center } => Handler::set_center_point(socket, channels, channel, center),
             Command::Pid { channel, parameter, value } => Handler::set_pid(socket, channels, channel, parameter, value),
             Command::SteinhartHart { channel, parameter, value } => Handler::set_steinhart_hart(socket, channels, channel, parameter, value),

src/dfu.rs

@@ -1,3 +1,4 @@
+use core::arch::asm;
 use cortex_m_rt::pre_init;
 use stm32f4xx_hal::stm32::{RCC, SYSCFG};
 

src/main.rs

@@ -1,11 +1,10 @@
 #![cfg_attr(not(test), no_std)]
 #![cfg_attr(not(test), no_main)]
-#![feature(maybe_uninit_extra, asm)]
 #![cfg_attr(test, allow(unused))]
 // TODO: #![deny(warnings, unused)]
 
 #[cfg(not(any(feature = "semihosting", test)))]
-use panic_abort as _;
+use panic_halt as _;
 #[cfg(all(feature = "semihosting", not(test)))]
 use panic_semihosting as _;
 
@@ -217,7 +216,7 @@ fn main() -> ! {
                                 // Do nothing and feed more data to the line reader in the next loop cycle.
                                 Ok(SessionInput::Nothing) => {}
                                 Ok(SessionInput::Command(command)) => {
-                                    match Handler::handle_command(command, &mut socket, &mut channels, session, &mut leds, &mut store, &mut ipv4_config, &mut fan_ctrl, hwrev) {
+                                    match Handler::handle_command(command, &mut socket, &mut channels, session, &mut store, &mut ipv4_config, &mut fan_ctrl, hwrev) {
                                         Ok(Handler::NewIPV4(ip)) => new_ipv4_config = Some(ip),                                
                                         Ok(Handler::Handled) => {},
                                         Ok(Handler::CloseSocket) => socket.close(),

src/server.rs

@@ -1,4 +1,3 @@
-use core::mem::MaybeUninit;
 use smoltcp::{
     iface::EthernetInterface,
     socket::{SocketSet, SocketHandle, TcpSocket, TcpSocketBuffer, SocketRef},
@@ -13,6 +12,18 @@ pub struct SocketState<S> {
     state: S,
 }
 
+impl<'a, S: Default> SocketState<S>{
+    fn new(sockets: &mut SocketSet<'a>, tcp_rx_storage: &'a mut [u8; TCP_RX_BUFFER_SIZE], tcp_tx_storage: &'a mut [u8; TCP_TX_BUFFER_SIZE]) -> SocketState<S> {
+        let tcp_rx_buffer = TcpSocketBuffer::new(&mut tcp_rx_storage[..]);
+        let tcp_tx_buffer = TcpSocketBuffer::new(&mut tcp_tx_storage[..]);
+        let tcp_socket = TcpSocket::new(tcp_rx_buffer, tcp_tx_buffer);
+        SocketState::<S> {
+            handle: sockets.add(tcp_socket),
+            state: S::default()
+        }
+    }
+}
+
 /// Number of server sockets and therefore concurrent client
 /// sessions. Many data structures in `Server::run()` correspond to
 /// this const.
@@ -35,28 +46,27 @@ impl<'a, 'b, S: Default> Server<'a, 'b, S> {
     where
         F: FnOnce(&mut Server<'a, '_, S>),
     {
-        let mut sockets_storage: [_; SOCKET_COUNT] = Default::default();
-        let mut sockets = SocketSet::new(&mut sockets_storage[..]);
-        let mut states: [SocketState<S>; SOCKET_COUNT] = unsafe { MaybeUninit::uninit().assume_init() };
-
-        macro_rules! create_socket {
-            ($set:ident, $rx_storage:ident, $tx_storage:ident, $target:expr) => {
+        macro_rules! create_rtx_storage {
+            ($rx_storage:ident, $tx_storage:ident) => {
                 let mut $rx_storage = [0; TCP_RX_BUFFER_SIZE];
                 let mut $tx_storage = [0; TCP_TX_BUFFER_SIZE];
-                let tcp_rx_buffer = TcpSocketBuffer::new(&mut $rx_storage[..]);
-                let tcp_tx_buffer = TcpSocketBuffer::new(&mut $tx_storage[..]);
-                let tcp_socket = TcpSocket::new(tcp_rx_buffer, tcp_tx_buffer);
-                $target = $set.add(tcp_socket);
             }
         }
-        create_socket!(sockets, tcp_rx_storage0, tcp_tx_storage0, states[0].handle);
-        create_socket!(sockets, tcp_rx_storage1, tcp_tx_storage1, states[1].handle);
-        create_socket!(sockets, tcp_rx_storage2, tcp_tx_storage2, states[2].handle);
-        create_socket!(sockets, tcp_rx_storage3, tcp_tx_storage3, states[3].handle);
 
-        for state in &mut states {
-            state.state = S::default();
-        }
+        create_rtx_storage!(tcp_rx_storage0, tcp_tx_storage0);
+        create_rtx_storage!(tcp_rx_storage1, tcp_tx_storage1);
+        create_rtx_storage!(tcp_rx_storage2, tcp_tx_storage2);
+        create_rtx_storage!(tcp_rx_storage3, tcp_tx_storage3);
+
+        let mut sockets_storage: [_; SOCKET_COUNT] = Default::default();
+        let mut sockets = SocketSet::new(&mut sockets_storage[..]);
+
+        let states: [SocketState<S>; SOCKET_COUNT] = [
+            SocketState::<S>::new(&mut sockets, &mut tcp_rx_storage0, &mut tcp_tx_storage0),
+            SocketState::<S>::new(&mut sockets, &mut tcp_rx_storage1, &mut tcp_tx_storage1),
+            SocketState::<S>::new(&mut sockets, &mut tcp_rx_storage2, &mut tcp_tx_storage2),
+            SocketState::<S>::new(&mut sockets, &mut tcp_rx_storage3, &mut tcp_tx_storage3),
+        ];
 
         let mut server = Server {
             states,