Add command to show firmware version

Makes debugging easier

README.md

@@ -45,7 +45,7 @@ There are several options for flashing Thermostat. DFU requires only a micro-USB
 
 ### dfu-util on Linux
 * Install the DFU USB tool (dfu-util).
-* Convert firmware from ELF to BIN: `llvm-objcopy -O binary target/thumbv7em-none-eabihf/release/thermostat thermostat.bin` (you can skip this step if using the BIN from Hydra)
+* Convert firmware from ELF to BIN: `arm-none-eabi-objcopy -O binary thermostat thermostat.bin` (you can skip this step if using the BIN from Hydra)
 * Connect to the Micro USB connector to Thermostat below the RJ45.
 * Add jumper to Thermostat v2.0 across 2-pin jumper adjacent to JTAG connector.
 * Cycle board power to put it in DFU update mode
@@ -271,19 +271,18 @@ with the following keys.
 | `tec_u_meas`   | Volts           | Measurement of the voltage across the TEC            |
 | `pid_output`   | Amperes         | PID control output                                   |
 
-Note: With Thermostat v2 and below, the voltage and current readouts `i_tec` and `tec_i` are noisy without the hardware fix shown in [this PR][https://git.m-labs.hk/M-Labs/thermostat/pulls/105].
-
 ## PID Tuning
 
 The thermostat implements a PID control loop for each of the TEC channels, more details on setting up the PID control loop can be found [here](./doc/PID%20tuning.md).
 
 ## Fan control
 
-Fan control commands are available for thermostat revisions with an integrated fan system:
+Fan control is available for the thermostat revisions with integrated fan system. For this purpose four commands are available:
 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, where fan speed is controlled by the fan curve `fcurve`.
+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 completely disable the fan.
+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.
 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`, a normalized value in range [0,1],
+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. 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].
+i.e. receives values from 0 to 1 linearly tied to the maximum current. The controlling curve should produce values from 0 to 1,
-5. `fcurve default` - restore fan curve coefficients to defaults: `a = 1.0, b = 0.0, c = 0.0`.
+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`.

flake.lock

@@ -1,45 +1,41 @@
 {
   "nodes": {
+    "mozilla-overlay": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1690536331,
+        "narHash": "sha256-aRIf2FB2GTdfF7gl13WyETmiV/J7EhBGkSWXfZvlxcA=",
+        "owner": "mozilla",
+        "repo": "nixpkgs-mozilla",
+        "rev": "db89c8707edcffefcd8e738459d511543a339ff5",
+        "type": "github"
+      },
+      "original": {
+        "owner": "mozilla",
+        "repo": "nixpkgs-mozilla",
+        "type": "github"
+      }
+    },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1722791413,
+        "lastModified": 1691421349,
-        "narHash": "sha256-rCTrlCWvHzMCNcKxPE3Z/mMK2gDZ+BvvpEVyRM4tKmU=",
+        "narHash": "sha256-RRJyX0CUrs4uW4gMhd/X4rcDG8PTgaaCQM5rXEJOx6g=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "8b5b6723aca5a51edf075936439d9cd3947b7b2c",
+        "rev": "011567f35433879aae5024fc6ec53f2a0568a6c4",
         "type": "github"
       },
       "original": {
         "owner": "NixOS",
-        "ref": "nixos-24.05",
+        "ref": "nixos-23.05",
         "repo": "nixpkgs",
         "type": "github"
       }
     },
     "root": {
       "inputs": {
-        "nixpkgs": "nixpkgs",
+        "mozilla-overlay": "mozilla-overlay",
-        "rust-overlay": "rust-overlay"
+        "nixpkgs": "nixpkgs"
-      }
-    },
-    "rust-overlay": {
-      "inputs": {
-        "nixpkgs": [
-          "nixpkgs"
-        ]
-      },
-      "locked": {
-        "lastModified": 1719281921,
-        "narHash": "sha256-LIBMfhM9pMOlEvBI757GOK5l0R58SRi6YpwfYMbf4yc=",
-        "owner": "oxalica",
-        "repo": "rust-overlay",
-        "rev": "b6032d3a404d8a52ecfc8571ff0c26dfbe221d07",
-        "type": "github"
-      },
-      "original": {
-        "owner": "oxalica",
-        "repo": "rust-overlay",
-        "type": "github"
       }
     }
   },

flake.nix

@@ -1,25 +1,32 @@
 {
   description = "Firmware for the Sinara 8451 Thermostat";
 
-  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-24.05";
+  inputs.nixpkgs.url = github:NixOS/nixpkgs/nixos-23.05;
-  inputs.rust-overlay = { 
+  inputs.mozilla-overlay = { url = github:mozilla/nixpkgs-mozilla; flake = false; };
-    url = "github:oxalica/rust-overlay";
-    inputs.nixpkgs.follows = "nixpkgs";
-  };
 
-  outputs = { self, nixpkgs, rust-overlay }:
+  outputs = { self, nixpkgs, mozilla-overlay }:
     let
-      pkgs = import nixpkgs { system = "x86_64-linux"; overlays = [ (import rust-overlay) ]; };
+      pkgs = import nixpkgs { system = "x86_64-linux"; overlays = [ (import mozilla-overlay) ]; };
-
+      rustManifest = pkgs.fetchurl {
-      rust = pkgs.rust-bin.stable."1.66.0".default.override {
+        url = "https://static.rust-lang.org/dist/2022-12-15/channel-rust-stable.toml";
-        extensions = [ "rust-src" ];
+        hash = "sha256-S7epLlflwt0d1GZP44u5Xosgf6dRrmr8xxC+Ml2Pq7c=";
-        targets = [ "thumbv7em-none-eabihf" ];
       };
-      rustPlatform = pkgs.makeRustPlatform {
+
+      targets = [
+        "thumbv7em-none-eabihf"
+      ];
+      rustChannelOfTargets = _channel: _date: targets:
+        (pkgs.lib.rustLib.fromManifestFile rustManifest {
+          inherit (pkgs) stdenv lib fetchurl patchelf;
+          }).rust.override {
+          inherit targets;
+          extensions = ["rust-src"];
+        };
+      rust = rustChannelOfTargets "stable" null targets;
+      rustPlatform = pkgs.recurseIntoAttrs (pkgs.makeRustPlatform {
         rustc = rust;
         cargo = rust;
-      };
+      });
-
       thermostat = rustPlatform.buildRustPackage {
         name = "thermostat";
         version = "0.0.0";
@@ -47,26 +54,24 @@
         '';
 
         dontFixup = true;
-        auditable = false;
       };
     in {
       packages.x86_64-linux = {
         inherit thermostat;
-        default = thermostat;
       };
 
       hydraJobs = {
         inherit thermostat;
       };
 
-      devShells.x86_64-linux.default = pkgs.mkShellNoCC {
+      devShell.x86_64-linux = pkgs.mkShell {
         name = "thermostat-dev-shell";
-        packages = with pkgs; [
+        buildInputs = with pkgs; [
-          rust llvm
+          rust openocd dfu-util
-          openocd dfu-util
           ] ++ (with python3Packages; [
             numpy matplotlib
           ]);
       };
+      defaultPackage.x86_64-linux = thermostat;
     };
 }

src/channel_state.rs

@@ -2,13 +2,11 @@ use smoltcp::time::{Duration, Instant};
 use uom::si::{
     f64::{
         ElectricPotential,
-        ElectricCurrent,
         ElectricalResistance,
         ThermodynamicTemperature,
         Time,
     },
     electric_potential::volt,
-    electric_current::ampere,
     electrical_resistance::ohm,
     thermodynamic_temperature::degree_celsius,
     time::millisecond,
@@ -31,7 +29,6 @@ pub struct ChannelState {
     /// i_set 0A center point
     pub center: CenterPoint,
     pub dac_value: ElectricPotential,
-    pub i_set: ElectricCurrent,
     pub pid_engaged: bool,
     pub pid: pid::Controller,
     pub sh: sh::Parameters,
@@ -47,7 +44,6 @@ impl ChannelState {
             adc_interval: Duration::from_millis(100),
             center: CenterPoint::Vref,
             dac_value: ElectricPotential::new::<volt>(0.0),
-            i_set: ElectricCurrent::new::<ampere>(0.0),
             pid_engaged: false,
             pid: pid::Controller::new(pid::Parameters::default()),
             sh: sh::Parameters::default(),

src/channels.rs

@@ -1,6 +1,5 @@
-use core::marker::PhantomData;
+use core::cmp::max_by;
 use heapless::{consts::U2, Vec};
-use num_traits::Zero;
 use serde::{Serialize, Serializer};
 use smoltcp::time::Instant;
 use stm32f4xx_hal::hal;
@@ -19,38 +18,15 @@ use crate::{
     channel_state::ChannelState,
     command_parser::{CenterPoint, PwmPin},
     command_handler::JsonBuffer,
-    pins::{self, Channel0VRef, Channel1VRef},
+    pins,
     steinhart_hart,
 };
 
-pub enum PinsAdcReadTarget {
-    VREF,
-    DacVfb,
-    ITec,
-    VTec,
-}
-
 pub const CHANNELS: usize = 2;
 pub const R_SENSE: f64 = 0.05;
-
-// From design specs
-pub const MAX_TEC_I: ElectricCurrent = ElectricCurrent {
-    dimension: PhantomData,
-    units: PhantomData,
-    value: 2.0,
-};
-pub const MAX_TEC_V: ElectricPotential = ElectricPotential {
-    dimension: PhantomData,
-    units: PhantomData,
-    value: 4.0,
-};
-
 // DAC chip outputs 0-5v, which is then passed through a resistor dividor to provide 0-3v range
-const DAC_OUT_V_MAX: ElectricPotential = ElectricPotential {
+const DAC_OUT_V_MAX: f64 = 3.0;
-    dimension: PhantomData,
+
-    units: PhantomData,
-    value: 3.0,
-};
 // TODO: -pub
 pub struct Channels {
     channel0: Channel<Channel0>,
@@ -122,7 +98,7 @@ impl Channels {
     pub fn get_center(&mut self, channel: usize) -> ElectricPotential {
         match self.channel_state(channel).center {
             CenterPoint::Vref =>
-                self.adc_read(channel, PinsAdcReadTarget::VREF, 8),
+                self.read_vref(channel),
             CenterPoint::Override(center_point) =>
                 ElectricPotential::new::<volt>(center_point.into()),
         }
@@ -135,13 +111,16 @@ impl Channels {
     }
 
     pub fn get_i(&mut self, channel: usize) -> ElectricCurrent {
-        let i_set = self.channel_state(channel).i_set;
+        let center_point = self.get_center(channel);
-        i_set
+        let r_sense = ElectricalResistance::new::<ohm>(R_SENSE);
+        let voltage = self.get_dac(channel);
+        let i_tec = (voltage - center_point) / (10.0 * r_sense);
+        i_tec
     }
 
     /// i_set DAC
     fn set_dac(&mut self, channel: usize, voltage: ElectricPotential) -> ElectricPotential {
-        let value = ((voltage / DAC_OUT_V_MAX).get::<ratio>() * (ad5680::MAX_VALUE as f64)) as u32 ;
+        let value = ((voltage / ElectricPotential::new::<volt>(DAC_OUT_V_MAX)).get::<ratio>() * (ad5680::MAX_VALUE as f64)) as u32 ;
         match channel {
             0 => self.channel0.dac.set(value).unwrap(),
             1 => self.channel1.dac.set(value).unwrap(),
@@ -151,8 +130,7 @@ impl Channels {
         voltage
     }
 
-    pub fn set_i(&mut self, channel: usize, i_set: ElectricCurrent) -> ElectricCurrent {
+    pub fn set_i(&mut self, channel: usize, i_tec: ElectricCurrent) -> ElectricCurrent {
-        let i_set = i_set.min(MAX_TEC_I).max(-MAX_TEC_I);
         let vref_meas = match channel.into() {
             0 => self.channel0.vref_meas,
             1 => self.channel1.vref_meas,
@@ -160,119 +138,38 @@ impl Channels {
         };
         let center_point = vref_meas;
         let r_sense = ElectricalResistance::new::<ohm>(R_SENSE);
-        let voltage = i_set * 10.0 * r_sense + center_point;
+        let voltage = i_tec * 10.0 * r_sense + center_point;
         let voltage = self.set_dac(channel, voltage);
-        let i_set = (voltage - center_point) / (10.0 * r_sense);
+        let i_tec = (voltage - center_point) / (10.0 * r_sense);
-        self.channel_state(channel).i_set = i_set;
+        i_tec
-        i_set
     }
 
-    /// AN4073: ADC Reading Dispersion can be reduced through Averaging
+    pub fn read_dac_feedback(&mut self, channel: usize) -> ElectricPotential {
-    pub fn adc_read(&mut self, channel: usize, adc_read_target: PinsAdcReadTarget, avg_pt: u16) -> ElectricPotential {
-        let mut sample: u32 = 0;
         match channel {
             0 => {
-                sample = match adc_read_target {
+                let sample = self.pins_adc.convert(
-                    PinsAdcReadTarget::VREF => {
+                    &self.channel0.dac_feedback_pin,
-                        match &self.channel0.vref_pin {
+                    stm32f4xx_hal::adc::config::SampleTime::Cycles_480
-                            Channel0VRef::Analog(vref_pin) => {
+                );
-                                for _ in (0..avg_pt).rev() {
+                let mv = self.pins_adc.sample_to_millivolts(sample);
-                                    sample += self
-                                        .pins_adc
-                                        .convert(vref_pin, stm32f4xx_hal::adc::config::SampleTime::Cycles_480)
-                                        as u32;
-                                }
-                                sample / avg_pt as u32
-                            },
-                            Channel0VRef::Disabled(_) => {2048 as u32}
-                        }
-                    }
-                    PinsAdcReadTarget::DacVfb => {
-                        for _ in (0..avg_pt).rev() {
-                            sample += self
-                                .pins_adc
-                                .convert(&self.channel0.dac_feedback_pin,stm32f4xx_hal::adc::config::SampleTime::Cycles_480)
-                                as u32;
-                        }
-                        sample / avg_pt as u32
-                    }
-                    PinsAdcReadTarget::ITec => {
-                        for _ in (0..avg_pt).rev() {
-                            sample += self
-                                .pins_adc
-                                .convert(&self.channel0.itec_pin, stm32f4xx_hal::adc::config::SampleTime::Cycles_480)
-                                as u32;
-                        }
-                        sample / avg_pt as u32
-                    }
-                    PinsAdcReadTarget::VTec => {
-                        for _ in (0..avg_pt).rev() {
-                            sample += self
-                                .pins_adc
-                                .convert(&self.channel0.tec_u_meas_pin, stm32f4xx_hal::adc::config::SampleTime::Cycles_480)
-                                as u32;
-                        }
-                        sample / avg_pt as u32
-                    }
-                };
-                let mv = self.pins_adc.sample_to_millivolts(sample as u16);
                 ElectricPotential::new::<millivolt>(mv as f64)
             }
             1 => {
-                sample = match adc_read_target {
+                let sample = self.pins_adc.convert(
-                    PinsAdcReadTarget::VREF => {
+                    &self.channel1.dac_feedback_pin,
-                        match &self.channel1.vref_pin {
+                    stm32f4xx_hal::adc::config::SampleTime::Cycles_480
-                            Channel1VRef::Analog(vref_pin) => {
+                );
-                                for _ in (0..avg_pt).rev() {
+                let mv = self.pins_adc.sample_to_millivolts(sample);
-                                    sample += self
-                                        .pins_adc
-                                        .convert(vref_pin, stm32f4xx_hal::adc::config::SampleTime::Cycles_480)
-                                        as u32;
-                                }
-                                sample / avg_pt as u32
-                            },
-                            Channel1VRef::Disabled(_) => {2048 as u32}
-                        }
-                    }
-                    PinsAdcReadTarget::DacVfb => {
-                        for _ in (0..avg_pt).rev() {
-                            sample += self
-                                .pins_adc
-                                .convert(&self.channel1.dac_feedback_pin, stm32f4xx_hal::adc::config::SampleTime::Cycles_480)
-                                as u32;
-                        }
-                        sample / avg_pt as u32
-                    }
-                    PinsAdcReadTarget::ITec => {
-                        for _ in (0..avg_pt).rev() {
-                            sample += self
-                                .pins_adc
-                                .convert(&self.channel1.itec_pin, stm32f4xx_hal::adc::config::SampleTime::Cycles_480)
-                                as u32;
-                        }
-                        sample / avg_pt as u32
-                    }
-                    PinsAdcReadTarget::VTec => {
-                        for _ in (0..avg_pt).rev() {
-                            sample += self
-                                .pins_adc
-                                .convert(&self.channel1.tec_u_meas_pin, stm32f4xx_hal::adc::config::SampleTime::Cycles_480)
-                                as u32;
-                        }
-                        sample / avg_pt as u32
-                    }
-                };
-                let mv = self.pins_adc.sample_to_millivolts(sample as u16);
                 ElectricPotential::new::<millivolt>(mv as f64)
             }
-            _ => unreachable!()
+            _ => unreachable!(),
         }
     }
 
     pub fn read_dac_feedback_until_stable(&mut self, channel: usize, tolerance: ElectricPotential) -> ElectricPotential {
-        let mut prev = self.adc_read(channel, PinsAdcReadTarget::DacVfb, 1);
+        let mut prev = self.read_dac_feedback(channel);
         loop {
-            let current = self.adc_read(channel, PinsAdcReadTarget::DacVfb, 1);
+            let current = self.read_dac_feedback(channel);
             if (current - prev).abs() < tolerance {
                 return current;
             }
@@ -280,6 +177,73 @@ impl Channels {
         }
     }
 
+    pub fn read_itec(&mut self, channel: usize) -> ElectricPotential {
+        match channel {
+            0 => {
+                let sample = self.pins_adc.convert(
+                    &self.channel0.itec_pin,
+                    stm32f4xx_hal::adc::config::SampleTime::Cycles_480
+                );
+                let mv = self.pins_adc.sample_to_millivolts(sample);
+                ElectricPotential::new::<millivolt>(mv as f64)
+            }
+            1 => {
+                let sample = self.pins_adc.convert(
+                    &self.channel1.itec_pin,
+                    stm32f4xx_hal::adc::config::SampleTime::Cycles_480
+                );
+                let mv = self.pins_adc.sample_to_millivolts(sample);
+                ElectricPotential::new::<millivolt>(mv as f64)
+            }
+            _ => unreachable!(),
+        }
+    }
+
+    /// should be 1.5V
+    pub fn read_vref(&mut self, channel: usize) -> ElectricPotential {
+        match channel {
+            0 => {
+                let sample = self.pins_adc.convert(
+                    &self.channel0.vref_pin,
+                    stm32f4xx_hal::adc::config::SampleTime::Cycles_480
+                );
+                let mv = self.pins_adc.sample_to_millivolts(sample);
+                ElectricPotential::new::<millivolt>(mv as f64)
+            }
+            1 => {
+                let sample = self.pins_adc.convert(
+                    &self.channel1.vref_pin,
+                    stm32f4xx_hal::adc::config::SampleTime::Cycles_480
+                );
+                let mv = self.pins_adc.sample_to_millivolts(sample);
+                ElectricPotential::new::<millivolt>(mv as f64)
+            }
+            _ => unreachable!(),
+        }
+    }
+
+    pub fn read_tec_u_meas(&mut self, channel: usize) -> ElectricPotential {
+        match channel {
+            0 => {
+                let sample = self.pins_adc.convert(
+                    &self.channel0.tec_u_meas_pin,
+                    stm32f4xx_hal::adc::config::SampleTime::Cycles_480
+                );
+                let mv = self.pins_adc.sample_to_millivolts(sample);
+                ElectricPotential::new::<millivolt>(mv as f64)
+            }
+            1 => {
+                let sample = self.pins_adc.convert(
+                    &self.channel1.tec_u_meas_pin,
+                    stm32f4xx_hal::adc::config::SampleTime::Cycles_480
+                );
+                let mv = self.pins_adc.sample_to_millivolts(sample);
+                ElectricPotential::new::<millivolt>(mv as f64)
+            }
+            _ => unreachable!(),
+        }
+    }
+
     /// Calibrates the DAC output to match vref of the MAX driver to reduce zero-current offset of the MAX driver output.
     ///
     /// The thermostat DAC applies a control voltage signal to the CTLI pin of MAX driver chip to control its output current.
@@ -327,7 +291,7 @@ impl Channels {
                     best_error = error;
                     start_value = prev_value;
 
-                    let vref = (value as f64 / ad5680::MAX_VALUE as f64) * DAC_OUT_V_MAX;
+                    let vref = (value as f64 / ad5680::MAX_VALUE as f64) * ElectricPotential::new::<volt>(DAC_OUT_V_MAX);
                     match channel {
                         0 => self.channel0.vref_meas = vref,
                         1 => self.channel1.vref_meas = vref,
@@ -387,32 +351,32 @@ impl Channels {
         }
     }
 
-    pub fn get_max_v(&mut self, channel: usize) -> (ElectricPotential, ElectricPotential) {
+    pub fn get_max_v(&mut self, channel: usize) -> ElectricPotential {
         let max = 4.0 * ElectricPotential::new::<volt>(3.3);
         let duty = self.get_pwm(channel, PwmPin::MaxV);
-        (duty * max, MAX_TEC_V)
+        duty * max
     }
 
     pub fn get_max_i_pos(&mut self, channel: usize) -> (ElectricCurrent, ElectricCurrent) {
         let max = ElectricCurrent::new::<ampere>(3.0);
         let duty = self.get_pwm(channel, PwmPin::MaxIPos);
-        (duty * max, MAX_TEC_I)
+        (duty * max, max)
     }
 
     pub fn get_max_i_neg(&mut self, channel: usize) -> (ElectricCurrent, ElectricCurrent) {
         let max = ElectricCurrent::new::<ampere>(3.0);
         let duty = self.get_pwm(channel, PwmPin::MaxINeg);
-        (duty * max, MAX_TEC_I)
+        (duty * max, max)
     }
 
     // Get current passing through TEC
     pub fn get_tec_i(&mut self, channel: usize) -> ElectricCurrent {
-        (self.adc_read(channel, PinsAdcReadTarget::ITec, 16) - self.adc_read(channel, PinsAdcReadTarget::VREF, 16)) / ElectricalResistance::new::<ohm>(0.4)
+        (self.read_itec(channel) - self.read_vref(channel)) / ElectricalResistance::new::<ohm>(0.4)
     }
 
     // Get voltage across TEC
     pub fn get_tec_v(&mut self, channel: usize) -> ElectricPotential {
-        (self.adc_read(channel, PinsAdcReadTarget::VTec, 16) - ElectricPotential::new::<volt>(1.5)) * 4.0
+        (self.read_tec_u_meas(channel) - ElectricPotential::new::<volt>(1.5)) * 4.0
     }
 
     fn set_pwm(&mut self, channel: usize, pin: PwmPin, duty: f64) -> f64 {
@@ -444,28 +408,28 @@ impl Channels {
 
     pub fn set_max_v(&mut self, channel: usize, max_v: ElectricPotential) -> (ElectricPotential, ElectricPotential) {
         let max = 4.0 * ElectricPotential::new::<volt>(3.3);
-        let duty = (max_v.min(MAX_TEC_V).max(ElectricPotential::zero()) / max).get::<ratio>();
+        let duty = (max_v / max).get::<ratio>();
         let duty = self.set_pwm(channel, PwmPin::MaxV, duty);
         (duty * max, max)
     }
 
     pub fn set_max_i_pos(&mut self, channel: usize, max_i_pos: ElectricCurrent) -> (ElectricCurrent, ElectricCurrent) {
         let max = ElectricCurrent::new::<ampere>(3.0);
-        let duty = (max_i_pos.min(MAX_TEC_I).max(ElectricCurrent::zero()) / max).get::<ratio>();
+        let duty = (max_i_pos / max).get::<ratio>();
         let duty = self.set_pwm(channel, PwmPin::MaxIPos, duty);
         (duty * max, max)
     }
 
     pub fn set_max_i_neg(&mut self, channel: usize, max_i_neg: ElectricCurrent) -> (ElectricCurrent, ElectricCurrent) {
         let max = ElectricCurrent::new::<ampere>(3.0);
-        let duty = (max_i_neg.min(MAX_TEC_I).max(ElectricCurrent::zero()) / max).get::<ratio>();
+        let duty = (max_i_neg / max).get::<ratio>();
         let duty = self.set_pwm(channel, PwmPin::MaxINeg, duty);
         (duty * max, max)
     }
 
     fn report(&mut self, channel: usize) -> Report {
         let i_set = self.get_i(channel);
-        let i_tec = self.adc_read(channel, PinsAdcReadTarget::ITec, 16);
+        let i_tec = self.read_itec(channel);
         let tec_i = self.get_tec_i(channel);
         let dac_value = self.get_dac(channel);
         let state = self.channel_state(channel);
@@ -481,7 +445,7 @@ impl Channels {
             pid_engaged: state.pid_engaged,
             i_set,
             dac_value,
-            dac_feedback: self.adc_read(channel, PinsAdcReadTarget::DacVfb, 1),
+            dac_feedback: self.read_dac_feedback(channel),
             i_tec,
             tec_i,
             tec_u_meas: self.get_tec_v(channel),
@@ -518,8 +482,8 @@ impl Channels {
         PwmSummary {
             channel,
             center: CenterPointJson(self.channel_state(channel).center.clone()),
-            i_set: (self.get_i(channel), MAX_TEC_I).into(),
+            i_set: (self.get_i(channel), ElectricCurrent::new::<ampere>(3.0)).into(),
-            max_v: self.get_max_v(channel).into(),
+            max_v: (self.get_max_v(channel), ElectricPotential::new::<volt>(5.0)).into(),
             max_i_pos: self.get_max_i_pos(channel).into(),
             max_i_neg: self.get_max_i_neg(channel).into(),
         }
@@ -560,11 +524,10 @@ impl Channels {
         serde_json_core::to_vec(&summaries)
     }
 
-    pub fn current_abs_max_tec_i(&mut self) -> ElectricCurrent {
+    pub fn current_abs_max_tec_i(&mut self) -> f64 {
-        (0..CHANNELS)
+        max_by(self.get_tec_i(0).abs().get::<ampere>(),
-            .map(|channel| self.get_tec_i(channel).abs())
+               self.get_tec_i(1).abs().get::<ampere>(),
-            .max_by(|a, b| a.partial_cmp(b).unwrap_or(core::cmp::Ordering::Equal))
+               |a, b| a.partial_cmp(b).unwrap_or(core::cmp::Ordering::Equal))
-            .unwrap()
     }
 }
 

src/command_handler.rs

@@ -25,7 +25,6 @@ use super::{
     session::Session,
     FanCtrl,
     hw_rev::HWRev,
-    firmware_ver,
 };
 
 use uom::{
@@ -212,11 +211,11 @@ impl Handler {
     }
 
     fn set_center_point(socket: &mut TcpSocket, channels: &mut Channels, channel: usize, center: CenterPoint) -> Result<Handler, Error> {
-        let i_set = channels.get_i(channel);
+        let i_tec = channels.get_i(channel);
         let state = channels.channel_state(channel);
         state.center = center;
         if !state.pid_engaged {
-            channels.set_i(channel, i_set);
+            channels.set_i(channel, i_tec);
         }
         send_line(socket, b"{}");
         Ok(Handler::Handled)
@@ -350,7 +349,7 @@ impl Handler {
 
     fn set_fan(socket: &mut TcpSocket, fan_pwm: u32, fan_ctrl: &mut FanCtrl) -> Result<Handler, Error> {
         if !fan_ctrl.fan_available() {
-            send_line(socket, b"{ \"warning\": \"this thermostat doesn't have a fan!\" }");
+            send_line(socket, b"{ \"warning\": \"this thermostat doesn't have fan!\" }");
             return Ok(Handler::Handled);
         }
         fan_ctrl.set_auto_mode(false);
@@ -379,7 +378,7 @@ impl Handler {
 
     fn fan_auto(socket: &mut TcpSocket, fan_ctrl: &mut FanCtrl) -> Result<Handler, Error> {
         if !fan_ctrl.fan_available() {
-            send_line(socket, b"{ \"warning\": \"this thermostat doesn't have a fan!\" }");
+            send_line(socket, b"{ \"warning\": \"this thermostat doesn't have fan!\" }");
             return Ok(Handler::Handled);
         }
         fan_ctrl.set_auto_mode(true);
@@ -418,16 +417,12 @@ impl Handler {
     }
 
     fn show_firmware_version(socket: &mut TcpSocket) -> Result<Handler, Error> {
-        match firmware_ver::summary() {
+        if let Some(version) = built_info::GIT_VERSION {
-            Ok(buf) => {
+            send_line(socket, version.as_bytes());
-                send_line(socket, &buf);
+            Ok(Handler::Handled)
-                Ok(Handler::Handled)
+        } else {
-            }
+            send_line(socket, built_info::PKG_VERSION.as_bytes());
-            Err(e) => {
+            Ok(Handler::Handled)
-                error!("unable to serialize FirmwareVer summary: {:?}", e);
-                let _ = writeln!(socket, "{{\"error\":\"{:?}\"}}", e);
-                Err(Error::ReportError)
-            }
         }
     }
 
@@ -460,7 +455,7 @@ impl Handler {
             Command::FanCurve { k_a, k_b, k_c } => Handler::fan_curve(socket, fan_ctrl, k_a, k_b, k_c),
             Command::FanCurveDefaults => Handler::fan_defaults(socket, fan_ctrl),
             Command::ShowHWRev => Handler::show_hwrev(socket, hwrev),
-            Command::ShowFirmwareVer => Handler::show_firmware_version(socket),
+            Command::ShowFirmwareVer => Handler::show_firmware_version(socket)
         }
     }
 }

src/config.rs

@@ -1,4 +1,3 @@
-use num_traits::Zero;
 use serde::{Serialize, Deserialize};
 use uom::si::{
     electric_potential::volt,
@@ -19,7 +18,6 @@ pub struct ChannelConfig {
     pid: pid::Parameters,
     pid_target: f32,
     pid_engaged: bool,
-    i_set: ElectricCurrent,
     sh: steinhart_hart::Parameters,
     pwm: PwmLimits,
     /// uses variant `PostFilter::Invalid` instead of `None` to save space
@@ -35,17 +33,11 @@ impl ChannelConfig {
             .unwrap_or(PostFilter::Invalid);
 
         let state = channels.channel_state(channel);
-        let i_set = if state.pid_engaged { 
-            ElectricCurrent::zero() 
-        } else { 
-            state.i_set 
-        };
         ChannelConfig {
             center: state.center.clone(),
             pid: state.pid.parameters.clone(),
             pid_target: state.pid.target as f32,
             pid_engaged: state.pid_engaged,
-            i_set: i_set,
             sh: state.sh.clone(),
             pwm,
             adc_postfilter,
@@ -67,7 +59,6 @@ impl ChannelConfig {
             adc_postfilter => Some(adc_postfilter),
         };
         let _ = channels.adc.set_postfilter(channel as u8, adc_postfilter);
-        let _ = channels.set_i(channel, self.i_set);
     }
 }
 
@@ -80,7 +71,7 @@ struct PwmLimits {
 
 impl PwmLimits {
     pub fn new(channels: &mut Channels, channel: usize) -> Self {
-        let (max_v, _) = channels.get_max_v(channel);
+        let max_v = channels.get_max_v(channel);
         let (max_i_pos, _) = channels.get_max_i_pos(channel);
         let (max_i_neg, _) = channels.get_max_i_neg(channel);
         PwmLimits {

src/fan_ctrl.rs

@@ -4,18 +4,17 @@ use stm32f4xx_hal::{
     pwm::{self, PwmChannels},
     pac::TIM8,
 };
-use uom::si::{
+
-    f64::ElectricCurrent,
-    electric_current::ampere,
-};
 use crate::{
     hw_rev::HWSettings,
     command_handler::JsonBuffer,
-    channels::MAX_TEC_I,
 };
 
 pub type FanPin = PwmChannels<TIM8, pwm::C4>;
 
+// as stated in the schematics
+const MAX_TEC_I: f32 = 3.0;
+
 const MAX_USER_FAN_PWM: f32 = 100.0;
 const MIN_USER_FAN_PWM: f32 = 1.0;
 
@@ -51,10 +50,10 @@ impl FanCtrl {
         fan_ctrl
     }
 
-    pub fn cycle(&mut self, abs_max_tec_i: ElectricCurrent) {
+    pub fn cycle(&mut self, abs_max_tec_i: f32) {
-        self.abs_max_tec_i = abs_max_tec_i.get::<ampere>() as f32;
+        self.abs_max_tec_i = abs_max_tec_i;
         if self.fan_auto && self.hw_settings.fan_available {
-            let scaled_current = self.abs_max_tec_i / MAX_TEC_I.get::<ampere>() as f32;
+            let scaled_current = self.abs_max_tec_i / MAX_TEC_I;
             // do not limit upper bound, as it will be limited in the set_pwm()
             let pwm = (MAX_USER_FAN_PWM * (scaled_current * (scaled_current * self.k_a + self.k_b) + self.k_c)) as u32;
             self.set_pwm(pwm);

src/firmware_ver.rs

@@ -1,20 +0,0 @@
-use serde::Serialize;
-use crate::command_handler::JsonBuffer;
-
-mod built_info {
-    include!(concat!(env!("OUT_DIR"), "/built.rs"));
-}
-
-#[derive(Serialize)]
-pub struct FirmwareSummary {
-    git_hash: Option<&'static str>,
-    is_dirty: Option<bool>,
-}
-
-pub fn summary() -> Result<JsonBuffer, serde_json_core::ser::Error> {
-    let summary = FirmwareSummary {
-        git_hash: built_info::GIT_COMMIT_HASH,
-        is_dirty: built_info::GIT_DIRTY,
-    };
-    serde_json_core::to_vec(&summary)
-}

src/main.rs

@@ -55,7 +55,6 @@ use command_handler::Handler;
 mod fan_ctrl;
 use fan_ctrl::FanCtrl;
 mod hw_rev;
-mod firmware_ver;
 
 const HSE: MegaHertz = MegaHertz(8);
 #[cfg(not(feature = "semihosting"))]
@@ -186,7 +185,7 @@ fn main() -> ! {
                     server.for_each(|_, session| session.set_report_pending(channel.into()));
                 }
 
-                fan_ctrl.cycle(channels.current_abs_max_tec_i());
+                fan_ctrl.cycle(channels.current_abs_max_tec_i() as f32);
 
                 if channels.pid_engaged() {
                     leds.g3.on();

src/pid.rs

@@ -54,13 +54,15 @@ impl Controller {
     //       + x0 * (kp + ki + kd)
     //       - x1 * (kp + 2kd)
     //       + x2 * kd
+    //       + kp * (u0 - u1)
     // y0  = clip(y0', ymin, ymax)
     pub fn update(&mut self, input: f64) -> f64 {
         
         let mut output: f64 = self.y1 - self.target * f64::from(self.parameters.ki)
                             + input * f64::from(self.parameters.kp + self.parameters.ki + self.parameters.kd)
                             - self.x1 * f64::from(self.parameters.kp + 2.0 * self.parameters.kd)
-                            + self.x2 * f64::from(self.parameters.kd);
+                            + self.x2 * f64::from(self.parameters.kd)
+                            + f64::from(self.parameters.kp) * (self.target - self.u1);
         if output < self.parameters.output_min.into() {
             output = self.parameters.output_min.into();
         }

src/pins.rs

@@ -66,31 +66,21 @@ pub trait ChannelPins {
     type TecUMeasPin;
 }
 
-pub enum Channel0VRef {
-    Analog(PA0<Analog>),
-    Disabled(PA0<Input<Floating>>),
-}
-
 impl ChannelPins for Channel0 {
     type DacSpi = Dac0Spi;
     type DacSync = PE4<Output<PushPull>>;
     type Shdn = PE10<Output<PushPull>>;
-    type VRefPin = Channel0VRef;
+    type VRefPin = PA0<Analog>;
     type ItecPin = PA6<Analog>;
     type DacFeedbackPin = PA4<Analog>;
     type TecUMeasPin = PC2<Analog>;
 }
 
-pub enum Channel1VRef {
-    Analog(PA3<Analog>),
-    Disabled(PA3<Input<Floating>>),
-}
-
 impl ChannelPins for Channel1 {
     type DacSpi = Dac1Spi;
     type DacSync = PF6<Output<PushPull>>;
     type Shdn = PE15<Output<PushPull>>;
-    type VRefPin = Channel1VRef;
+    type VRefPin = PA3<Analog>;
     type ItecPin = PB0<Analog>;
     type DacFeedbackPin = PA5<Analog>;
     type TecUMeasPin = PC3<Analog>;
@@ -160,17 +150,13 @@ impl Pins {
             gpioe.pe13, gpioe.pe14
         );
 
-        let hwrev = HWRev::detect_hw_rev(&HWRevPins {hwrev0: gpiod.pd0, hwrev1: gpiod.pd1,
-            hwrev2: gpiod.pd2, hwrev3: gpiod.pd3});
-        let hw_settings = hwrev.settings();
-
         let (dac0_spi, dac0_sync) = Self::setup_dac0(
             clocks, spi4,
             gpioe.pe2, gpioe.pe4, gpioe.pe6
         );
         let mut shdn0 = gpioe.pe10.into_push_pull_output();
         let _ = shdn0.set_low();
-        let vref0_pin = if hwrev.major > 2 {Channel0VRef::Analog(gpioa.pa0.into_analog())} else {Channel0VRef::Disabled(gpioa.pa0)};
+        let vref0_pin = gpioa.pa0.into_analog();
         let itec0_pin = gpioa.pa6.into_analog();
         let dac_feedback0_pin = gpioa.pa4.into_analog();
         let tec_u_meas0_pin = gpioc.pc2.into_analog();
@@ -190,7 +176,7 @@ impl Pins {
         );
         let mut shdn1 = gpioe.pe15.into_push_pull_output();
         let _ = shdn1.set_low();
-        let vref1_pin = if hwrev.major > 2 {Channel1VRef::Analog(gpioa.pa3.into_analog())} else {Channel1VRef::Disabled(gpioa.pa3)};
+        let vref1_pin = gpioa.pa3.into_analog();
         let itec1_pin = gpiob.pb0.into_analog();
         let dac_feedback1_pin = gpioa.pa5.into_analog();
         let tec_u_meas1_pin = gpioc.pc3.into_analog();
@@ -212,6 +198,10 @@ impl Pins {
             channel1,
         };
 
+        let hwrev = HWRev::detect_hw_rev(&HWRevPins {hwrev0: gpiod.pd0, hwrev1: gpiod.pd1,
+            hwrev2: gpiod.pd2, hwrev3: gpiod.pd3});
+        let hw_settings = hwrev.settings();
+
         let leds = Leds::new(gpiod.pd9, gpiod.pd10.into_push_pull_output(), gpiod.pd11.into_push_pull_output());
 
         let eeprom_scl = gpiob.pb8.into_alternate().set_open_drain();