Fix wrong current limit duty cycle calculation

- prev commit assumed setting 3.3V -> 3A current limit which is wrong
- Please refer to the MAX1968 datasheet for the duty cycle
calculation equation

.gitignore

@@ -1,2 +1,5 @@
 target/
 result
+*.bin
+
+__pycache__/

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: `arm-none-eabi-objcopy -O binary thermostat thermostat.bin` (you can skip this step if using the BIN from Hydra)
+* 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)
 * 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
@@ -84,9 +84,7 @@ invalidate the first line of input.
 
 ### Reading ADC input
 
-Set report mode to `on` for a continuous stream of input data.
-
-The scope of this setting is per TCP session.
+ADC input data is provided in reports. Query for the latest report with the command `report`. See the *Reports* section below.
 
 
 ### TCP commands
@@ -97,8 +95,6 @@ formatted as line-delimited JSON.
 | Syntax                           | Function                                                                      |
 |----------------------------------|-------------------------------------------------------------------------------|
 | `report`                         | Show current input                                                            |
-| `report mode`                    | Show current report mode                                                      |
-| `report mode <off/on>`           | Set report mode                                                               |
 | `pwm`                            | Show current PWM settings                                                     |
 | `pwm <0/1> max_i_pos <amp>`      | Set maximum positive output current                                           |
 | `pwm <0/1> max_i_neg <amp>`      | Set maximum negative output current                                           |
@@ -251,8 +247,7 @@ pwm 0 pid
 
 ## Reports
 
-Use the bare `report` command to obtain a single report. Enable
-continuous reporting with `report mode on`. Reports are JSON objects
+Use the bare `report` command to obtain a single report. Reports are JSON objects
 with the following keys.
 
 | Key            | Unit            | Description                                          |
@@ -271,7 +266,7 @@ 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 disabled and null due to faulty hardware that introduces a lot of noise in the signal.
+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
 

flake.lock

@@ -1,41 +1,45 @@
 {
   "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": 1691421349,
-        "narHash": "sha256-RRJyX0CUrs4uW4gMhd/X4rcDG8PTgaaCQM5rXEJOx6g=",
+        "lastModified": 1722791413,
+        "narHash": "sha256-rCTrlCWvHzMCNcKxPE3Z/mMK2gDZ+BvvpEVyRM4tKmU=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "011567f35433879aae5024fc6ec53f2a0568a6c4",
+        "rev": "8b5b6723aca5a51edf075936439d9cd3947b7b2c",
         "type": "github"
       },
       "original": {
         "owner": "NixOS",
-        "ref": "nixos-23.05",
+        "ref": "nixos-24.05",
         "repo": "nixpkgs",
         "type": "github"
       }
     },
     "root": {
       "inputs": {
-        "mozilla-overlay": "mozilla-overlay",
-        "nixpkgs": "nixpkgs"
+        "nixpkgs": "nixpkgs",
+        "rust-overlay": "rust-overlay"
+      }
+    },
+    "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

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

pytec/pytec/client.py

@@ -1,6 +1,7 @@
 import socket
 import json
 import logging
+import time
 
 class CommandError(Exception):
     pass
@@ -126,9 +127,8 @@ class Client:
              'tec_u_meas': 2.5340000000000003,
              'pid_output': 2.067581958092247}
         """
-        self._command("report mode", "on")
-
         while True:
+            self._socket.sendall("report\n".encode('utf-8'))
             line = self._read_line()
             if not line:
                 break
@@ -136,6 +136,7 @@ class Client:
                 yield json.loads(line)
             except json.decoder.JSONDecodeError:
                 pass
+            time.sleep(0.05)
 
     def set_param(self, topic, channel, field="", value=""):
         """Set configuration parameters

src/channel.rs

@@ -24,7 +24,7 @@ pub struct Channel<C: ChannelPins> {
     pub vref_meas: ElectricPotential,
     pub shdn: C::Shdn,
     pub vref_pin: C::VRefPin,
-    pub itec_pin: C::ItecPin,
+    pub itec_pin: C::ITecPin,
     /// feedback from `dac` output
     pub dac_feedback_pin: C::DacFeedbackPin,
     pub tec_u_meas_pin: C::TecUMeasPin,

src/channels.rs

@@ -1,5 +1,6 @@
-use core::cmp::max_by;
+use core::marker::PhantomData;
 use heapless::{consts::U2, Vec};
+use num_traits::Zero;
 use serde::{Serialize, Serializer};
 use smoltcp::time::Instant;
 use stm32f4xx_hal::hal;
@@ -18,29 +19,55 @@ use crate::{
     channel_state::ChannelState,
     command_parser::{CenterPoint, PwmPin},
     command_handler::JsonBuffer,
-    pins,
+    pins::{self, Channel0VRef, Channel1VRef},
     steinhart_hart,
-    hw_rev,
 };
+use crate::timer::sleep;
+
+pub enum PinsAdcReadTarget {
+    VREF,
+    DacVfb,
+    ITec,
+    VTec,
+}
 
 pub const CHANNELS: usize = 2;
 pub const R_SENSE: f64 = 0.05;
-// DAC chip outputs 0-5v, which is then passed through a resistor dividor to provide 0-3v range
-const DAC_OUT_V_MAX: f64 = 3.0;
 
+// 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,
+};
+const MAX_TEC_I_DUTY_TO_CURRENT_RATE: ElectricCurrent = ElectricCurrent {
+    dimension: PhantomData,
+    units: PhantomData,
+    value: 1.0 / (10.0 * R_SENSE / 3.3),
+};
+// 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 {
+    dimension: PhantomData,
+    units: PhantomData,
+    value: 3.0,
+};
 // TODO: -pub
-pub struct Channels<'a> {
+pub struct Channels {
     channel0: Channel<Channel0>,
     channel1: Channel<Channel1>,
     pub adc: ad7172::Adc<pins::AdcSpi, pins::AdcNss>,
     /// stm32f4 integrated adc
     pins_adc: pins::PinsAdc,
     pub pwm: pins::PwmPins,
-    hwrev: &'a hw_rev::HWRev,
 }
 
-impl<'a> Channels<'a> {
-    pub fn new(pins: pins::Pins, hwrev: &'a hw_rev::HWRev) -> Self {
+impl Channels {
+    pub fn new(pins: pins::Pins) -> Self {
         let mut adc = ad7172::Adc::new(pins.adc_spi, pins.adc_nss).unwrap();
         // Feature not used
         adc.set_sync_enable(false).unwrap();
@@ -58,7 +85,7 @@ impl<'a> Channels<'a> {
         let channel1 = Channel::new(pins.channel1, adc_calibration1);
         let pins_adc = pins.pins_adc;
         let pwm = pins.pwm;
-        let mut channels = Channels { channel0, channel1, adc, pins_adc, pwm, hwrev };
+        let mut channels = Channels { channel0, channel1, adc, pins_adc, pwm };
         for channel in 0..CHANNELS {
             channels.calibrate_dac_value(channel);
             channels.set_i(channel, ElectricCurrent::new::<ampere>(0.0));
@@ -100,7 +127,7 @@ impl<'a> Channels<'a> {
     pub fn get_center(&mut self, channel: usize) -> ElectricPotential {
         match self.channel_state(channel).center {
             CenterPoint::Vref =>
-                self.read_vref(channel),
+                self.adc_read(channel, PinsAdcReadTarget::VREF, 8),
             CenterPoint::Override(center_point) =>
                 ElectricPotential::new::<volt>(center_point.into()),
         }
@@ -119,7 +146,7 @@ impl<'a> Channels<'a> {
 
     /// i_set DAC
     fn set_dac(&mut self, channel: usize, voltage: ElectricPotential) -> ElectricPotential {
-        let value = ((voltage / ElectricPotential::new::<volt>(DAC_OUT_V_MAX)).get::<ratio>() * (ad5680::MAX_VALUE as f64)) as u32 ;
+        let value = ((voltage / 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(),
@@ -130,6 +157,7 @@ impl<'a> Channels<'a> {
     }
 
     pub fn set_i(&mut self, channel: usize, i_set: 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,
@@ -144,103 +172,105 @@ impl<'a> Channels<'a> {
         i_set
     }
 
-    pub fn read_dac_feedback(&mut self, channel: usize) -> ElectricPotential {
+    /// AN4073: ADC Reading Dispersion can be reduced through Averaging
+    pub fn adc_read(&mut self, channel: usize, adc_read_target: PinsAdcReadTarget, avg_pt: u16) -> ElectricPotential {
+        let mut sample: u32 = 0;
         match channel {
             0 => {
-                let sample = self.pins_adc.convert(
-                    &self.channel0.dac_feedback_pin,
-                    stm32f4xx_hal::adc::config::SampleTime::Cycles_480
-                );
-                let mv = self.pins_adc.sample_to_millivolts(sample);
+                sample = match adc_read_target {
+                    PinsAdcReadTarget::VREF => {
+                        match &self.channel0.vref_pin {
+                            Channel0VRef::Analog(vref_pin) => {
+                                for _ in (0..avg_pt).rev() {
+                                    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 => {
-                let sample = self.pins_adc.convert(
-                    &self.channel1.dac_feedback_pin,
-                    stm32f4xx_hal::adc::config::SampleTime::Cycles_480
-                );
-                let mv = self.pins_adc.sample_to_millivolts(sample);
+                sample = match adc_read_target {
+                    PinsAdcReadTarget::VREF => {
+                        match &self.channel1.vref_pin {
+                            Channel1VRef::Analog(vref_pin) => {
+                                for _ in (0..avg_pt).rev() {
+                                    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!(),
-        }
-    }
-
-    pub fn read_dac_feedback_until_stable(&mut self, channel: usize, tolerance: ElectricPotential) -> ElectricPotential {
-        let mut prev = self.read_dac_feedback(channel);
-        loop {
-            let current = self.read_dac_feedback(channel);
-            if (current - prev).abs() < tolerance {
-                return current;
-            }
-            prev = current;
-        }
-    }
-
-    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!(),
+            _ => unreachable!()
         }
     }
 
@@ -270,8 +300,7 @@ impl<'a> Channels<'a> {
         let mut start_value = 1;
         let mut best_error = ElectricPotential::new::<volt>(100.0);
 
-        for step in (0..18).rev() {
-            let mut prev_value = start_value;
+        for step in (5..18).rev() {
             for value in (start_value..=ad5680::MAX_VALUE).step_by(1 << step) {
                 match channel {
                     0 => {
@@ -282,24 +311,23 @@ impl<'a> Channels<'a> {
                     }
                     _ => unreachable!(),
                 }
+                sleep(10);
 
-                let dac_feedback = self.read_dac_feedback_until_stable(channel, ElectricPotential::new::<volt>(0.001));
+                let dac_feedback = self.adc_read(channel, PinsAdcReadTarget::DacVfb, 64);
                 let error = target_voltage - dac_feedback;
                 if error < ElectricPotential::new::<volt>(0.0) {
                     break;
                 } else if error < best_error {
                     best_error = error;
-                    start_value = prev_value;
+                    start_value = value;
 
-                    let vref = (value as f64 / ad5680::MAX_VALUE as f64) * ElectricPotential::new::<volt>(DAC_OUT_V_MAX);
+                    let vref = (value as f64 / ad5680::MAX_VALUE as f64) * DAC_OUT_V_MAX;
                     match channel {
                         0 => self.channel0.vref_meas = vref,
                         1 => self.channel1.vref_meas = vref,
                         _ => unreachable!(),
                     }
                 }
-
-                prev_value = value;
             }
         }
 
@@ -351,32 +379,30 @@ impl<'a> Channels<'a> {
         }
     }
 
-    pub fn get_max_v(&mut self, channel: usize) -> ElectricPotential {
+    pub fn get_max_v(&mut self, channel: usize) -> (ElectricPotential, ElectricPotential) {
         let max = 4.0 * ElectricPotential::new::<volt>(3.3);
         let duty = self.get_pwm(channel, PwmPin::MaxV);
-        duty * max
+        (duty * max, MAX_TEC_V)
     }
 
     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)
+        (duty * MAX_TEC_I_DUTY_TO_CURRENT_RATE, MAX_TEC_I)
     }
 
     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)
+        (duty * MAX_TEC_I_DUTY_TO_CURRENT_RATE, MAX_TEC_I)
     }
 
     // Get current passing through TEC
     pub fn get_tec_i(&mut self, channel: usize) -> ElectricCurrent {
-        (self.read_itec(channel) - self.read_vref(channel)) / ElectricalResistance::new::<ohm>(0.4)
+        (self.adc_read(channel, PinsAdcReadTarget::ITec, 16) - self.adc_read(channel, PinsAdcReadTarget::VREF, 16)) / ElectricalResistance::new::<ohm>(0.4)
     }
 
     // Get voltage across TEC
     pub fn get_tec_v(&mut self, channel: usize) -> ElectricPotential {
-        (self.read_tec_u_meas(channel) - ElectricPotential::new::<volt>(1.5)) * 4.0
+        (self.adc_read(channel, PinsAdcReadTarget::VTec, 16) - ElectricPotential::new::<volt>(1.5)) * 4.0
     }
 
     fn set_pwm(&mut self, channel: usize, pin: PwmPin, duty: f64) -> f64 {
@@ -408,29 +434,29 @@ impl<'a> Channels<'a> {
 
     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 / max).get::<ratio>();
+        let duty = (max_v.min(MAX_TEC_V).max(ElectricPotential::zero()) / 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 / max).get::<ratio>();
+        let duty = (max_i_pos.min(MAX_TEC_I).max(ElectricCurrent::zero()) / MAX_TEC_I_DUTY_TO_CURRENT_RATE).get::<ratio>();
         let duty = self.set_pwm(channel, PwmPin::MaxIPos, duty);
-        (duty * max, max)
+        (duty * MAX_TEC_I_DUTY_TO_CURRENT_RATE, 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 / max).get::<ratio>();
+        let duty = (max_i_neg.min(MAX_TEC_I).max(ElectricCurrent::zero()) / MAX_TEC_I_DUTY_TO_CURRENT_RATE).get::<ratio>();
         let duty = self.set_pwm(channel, PwmPin::MaxINeg, duty);
-        (duty * max, max)
+        (duty * MAX_TEC_I_DUTY_TO_CURRENT_RATE, max)
     }
 
     fn report(&mut self, channel: usize) -> Report {
         let i_set = self.get_i(channel);
-        let i_tec = if self.hwrev.major > 2 {Some(self.read_itec(channel))} else {None};
-        let tec_i = if self.hwrev.major > 2 {Some(self.get_tec_i(channel))} else {None};
+        let i_tec = self.adc_read(channel, PinsAdcReadTarget::ITec, 16);
+        let tec_i = self.get_tec_i(channel);
         let dac_value = self.get_dac(channel);
         let state = self.channel_state(channel);
         let pid_output = ElectricCurrent::new::<ampere>(state.pid.y1);
@@ -445,7 +471,7 @@ impl<'a> Channels<'a> {
             pid_engaged: state.pid_engaged,
             i_set,
             dac_value,
-            dac_feedback: self.read_dac_feedback(channel),
+            dac_feedback: self.adc_read(channel, PinsAdcReadTarget::DacVfb, 1),
             i_tec,
             tec_i,
             tec_u_meas: self.get_tec_v(channel),
@@ -482,8 +508,8 @@ impl<'a> Channels<'a> {
         PwmSummary {
             channel,
             center: CenterPointJson(self.channel_state(channel).center.clone()),
-            i_set: (self.get_i(channel), ElectricCurrent::new::<ampere>(3.0)).into(),
-            max_v: (self.get_max_v(channel), ElectricPotential::new::<volt>(5.0)).into(),
+            i_set: (self.get_i(channel), MAX_TEC_I).into(),
+            max_v: self.get_max_v(channel).into(),
             max_i_pos: self.get_max_i_pos(channel).into(),
             max_i_neg: self.get_max_i_neg(channel).into(),
         }
@@ -525,9 +551,10 @@ impl<'a> Channels<'a> {
     }
 
     pub fn current_abs_max_tec_i(&mut self) -> ElectricCurrent {
-        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))
+        (0..CHANNELS)
+            .map(|channel| self.get_tec_i(channel).abs())
+            .max_by(|a, b| a.partial_cmp(b).unwrap_or(core::cmp::Ordering::Equal))
+            .unwrap()
     }
 }
 
@@ -543,8 +570,8 @@ pub struct Report {
     i_set: ElectricCurrent,
     dac_value: ElectricPotential,
     dac_feedback: ElectricPotential,
-    i_tec: Option<ElectricPotential>,
-    tec_i: Option<ElectricCurrent>,
+    i_tec: ElectricPotential,
+    tec_i: ElectricCurrent,
     tec_u_meas: ElectricPotential,
     pid_output: ElectricCurrent,
 }

src/command_handler.rs

@@ -22,7 +22,6 @@ use super::{
     config::ChannelConfig,
     dfu,
     flash_store::FlashStore,
-    session::Session,
     FanCtrl,
     hw_rev::HWRev,
 };
@@ -87,16 +86,6 @@ fn send_line(socket: &mut TcpSocket, data: &[u8]) -> bool {
 
 impl Handler {
 
-    fn reporting(socket: &mut TcpSocket) -> Result<Handler, Error> {
-        send_line(socket, b"{}");
-        Ok(Handler::Handled)
-    }
-
-    fn show_report_mode(socket: &mut TcpSocket, session: &Session) -> Result<Handler, Error> {
-        let _ = writeln!(socket, "{{ \"report\": {:?} }}", session.reporting());
-        Ok(Handler::Handled)
-    }
-
     fn show_report(socket: &mut TcpSocket, channels: &mut Channels) -> Result<Handler, Error> {
         match channels.reports_json() {
             Ok(buf) => {
@@ -345,7 +334,7 @@ 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 fan!\" }");
+            send_line(socket, b"{ \"warning\": \"this thermostat doesn't have a fan!\" }");
             return Ok(Handler::Handled);
         }
         fan_ctrl.set_auto_mode(false);
@@ -374,7 +363,7 @@ 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 fan!\" }");
+            send_line(socket, b"{ \"warning\": \"this thermostat doesn't have a fan!\" }");
             return Ok(Handler::Handled);
         }
         fan_ctrl.set_auto_mode(true);
@@ -412,11 +401,9 @@ impl Handler {
         }
     }
 
-    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> {
+    pub fn handle_command(command: Command, socket: &mut TcpSocket, channels: &mut Channels, 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),            
-            Command::Show(ShowCommand::Reporting) => Handler::show_report_mode(socket, session),            
             Command::Show(ShowCommand::Input) => Handler::show_report(socket, channels),
             Command::Show(ShowCommand::Pid) => Handler::show_pid(socket, channels),
             Command::Show(ShowCommand::Pwm) => Handler::show_pwm(socket, channels),

src/command_parser.rs

@@ -96,7 +96,6 @@ pub struct Ipv4Config {
 #[derive(Debug, Clone, PartialEq)]
 pub enum ShowCommand {
     Input,
-    Reporting,
     Pwm,
     Pid,
     SteinhartHart,
@@ -148,7 +147,6 @@ pub enum Command {
     Reset,
     Ipv4(Ipv4Config),
     Show(ShowCommand),
-    Reporting(bool),
     /// PWM parameter setting
     Pwm {
         channel: usize,
@@ -233,12 +231,6 @@ fn float(input: &[u8]) -> IResult<&[u8], Result<f64, Error>> {
     Ok((input, result))
 }
 
-fn off_on(input: &[u8]) -> IResult<&[u8], bool> {
-    alt((value(false, tag("off")),
-         value(true, tag("on"))
-    ))(input)
-}
-
 fn channel(input: &[u8]) -> IResult<&[u8], usize> {
     map(one_of("01"), |c| (c as usize) - ('0' as usize))(input)
 }
@@ -246,24 +238,8 @@ fn channel(input: &[u8]) -> IResult<&[u8], usize> {
 fn report(input: &[u8]) -> IResult<&[u8], Command> {
     preceded(
         tag("report"),
-        alt((
-            preceded(
-                whitespace,
-                preceded(
-                    tag("mode"),
-                    alt((
-                        preceded(
-                            whitespace,
-                            // `report mode <on | off>` - Switch repoting mode
-                            map(off_on, Command::Reporting)
-                        ),
-                        // `report mode` - Show current reporting state
-                        value(Command::Show(ShowCommand::Reporting), end)
-                    ))
-                )),
-            // `report` - Report once
-            value(Command::Show(ShowCommand::Input), end)
-        ))
+        // `report` - Report once
+        value(Command::Show(ShowCommand::Input), end)
     )(input)
 }
 
@@ -682,24 +658,6 @@ mod test {
         assert_eq!(command, Ok(Command::Show(ShowCommand::Input)));
     }
 
-    #[test]
-    fn parse_report_mode() {
-        let command = Command::parse(b"report mode");
-        assert_eq!(command, Ok(Command::Show(ShowCommand::Reporting)));
-    }
-
-    #[test]
-    fn parse_report_mode_on() {
-        let command = Command::parse(b"report mode on");
-        assert_eq!(command, Ok(Command::Reporting(true)));
-    }
-
-    #[test]
-    fn parse_report_mode_off() {
-        let command = Command::parse(b"report mode off");
-        assert_eq!(command, Ok(Command::Reporting(false)));
-    }
-
     #[test]
     fn parse_pwm_i_set() {
         let command = Command::parse(b"pwm 1 i_set 16383");

src/config.rs

@@ -1,3 +1,4 @@
+use num_traits::Zero;
 use serde::{Serialize, Deserialize};
 use uom::si::{
     electric_potential::volt,
@@ -18,6 +19,7 @@ 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
@@ -33,11 +35,17 @@ 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,
@@ -59,6 +67,7 @@ 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);
     }
 }
 
@@ -71,7 +80,7 @@ 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

@@ -11,13 +11,11 @@ use uom::si::{
 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;
 
@@ -56,7 +54,7 @@ impl FanCtrl {
     pub fn cycle(&mut self, abs_max_tec_i: ElectricCurrent) {
         self.abs_max_tec_i = abs_max_tec_i.get::<ampere>() as f32;
         if self.fan_auto && self.hw_settings.fan_available {
-            let scaled_current = self.abs_max_tec_i / MAX_TEC_I;
+            let scaled_current = self.abs_max_tec_i / MAX_TEC_I.get::<ampere>() as f32;
             // 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/main.rs

@@ -138,7 +138,7 @@ fn main() -> ! {
 
     let mut store = flash_store::store(dp.FLASH);
 
-    let mut channels = Channels::new(pins, &hwrev);
+    let mut channels = Channels::new(pins);
     for c in 0..CHANNELS {
         match store.read_value::<ChannelConfig>(CHANNEL_CONFIG_KEY[c]) {
             Ok(Some(config)) =>
@@ -180,10 +180,7 @@ fn main() -> ! {
             loop {
                 let mut new_ipv4_config = None;
                 let instant = Instant::from_millis(i64::from(timer::now()));
-                let updated_channel = channels.poll_adc(instant);
-                if let Some(channel) = updated_channel {
-                    server.for_each(|_, session| session.set_report_pending(channel.into()));
-                }
+                channels.poll_adc(instant);
 
                 fan_ctrl.cycle(channels.current_abs_max_tec_i());
 
@@ -216,7 +213,7 @@ 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 store, &mut ipv4_config, &mut fan_ctrl, hwrev) {
+                                    match Handler::handle_command(command, &mut socket, &mut channels, &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(),
@@ -231,19 +228,6 @@ fn main() -> ! {
                                 Err(_) =>
                                     socket.close(),
                             }
-                        } else if socket.can_send() {
-                            if let Some(channel) = session.is_report_pending() {
-                                match channels.reports_json() {
-                                    Ok(buf) => {
-                                        send_line(&mut socket, &buf[..]);
-                                        session.mark_report_sent(channel);
-                                    }
-                                    Err(e) => {
-                                        error!("unable to serialize report: {:?}", e);
-
-                                    }
-                                }
-                            }
                         }
                     });
                 } else {

src/pid.rs

@@ -54,15 +54,13 @@ 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)
-                            + f64::from(self.parameters.kp) * (self.target - self.u1);
+                            + self.x2 * f64::from(self.parameters.kd);
         if output < self.parameters.output_min.into() {
             output = self.parameters.output_min.into();
         }

src/pins.rs

@@ -61,27 +61,37 @@ pub trait ChannelPins {
     type DacSync: OutputPin;
     type Shdn: OutputPin;
     type VRefPin;
-    type ItecPin;
+    type ITecPin;
     type DacFeedbackPin;
     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 = PA0<Analog>;
-    type ItecPin = PA6<Analog>;
+    type VRefPin = Channel0VRef;
+    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 = PA3<Analog>;
-    type ItecPin = PB0<Analog>;
+    type VRefPin = Channel1VRef;
+    type ITecPin = PB0<Analog>;
     type DacFeedbackPin = PA5<Analog>;
     type TecUMeasPin = PC3<Analog>;
 }
@@ -98,7 +108,7 @@ pub struct ChannelPinSet<C: ChannelPins> {
     pub dac_sync: C::DacSync,
     pub shdn: C::Shdn,
     pub vref_pin: C::VRefPin,
-    pub itec_pin: C::ItecPin,
+    pub itec_pin: C::ITecPin,
     pub dac_feedback_pin: C::DacFeedbackPin,
     pub tec_u_meas_pin: C::TecUMeasPin,
 }
@@ -150,13 +160,17 @@ 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 = gpioa.pa0.into_analog();
+        let vref0_pin = if hwrev.major > 2 {Channel0VRef::Analog(gpioa.pa0.into_analog())} else {Channel0VRef::Disabled(gpioa.pa0)};
         let itec0_pin = gpioa.pa6.into_analog();
         let dac_feedback0_pin = gpioa.pa4.into_analog();
         let tec_u_meas0_pin = gpioc.pc2.into_analog();
@@ -176,7 +190,7 @@ impl Pins {
         );
         let mut shdn1 = gpioe.pe15.into_push_pull_output();
         let _ = shdn1.set_low();
-        let vref1_pin = gpioa.pa3.into_analog();
+        let vref1_pin = if hwrev.major > 2 {Channel1VRef::Analog(gpioa.pa3.into_analog())} else {Channel1VRef::Disabled(gpioa.pa3)};
         let itec1_pin = gpiob.pb0.into_analog();
         let dac_feedback1_pin = gpioa.pa5.into_analog();
         let tec_u_meas1_pin = gpioc.pc3.into_analog();
@@ -198,10 +212,6 @@ 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();

src/session.rs

@@ -1,5 +1,4 @@
 use super::command_parser::{Command, Error as ParserError};
-use super::channels::CHANNELS;
 
 const MAX_LINE_LEN: usize = 64;
 
@@ -53,8 +52,6 @@ impl From<Result<Command, ParserError>> for SessionInput {
 
 pub struct Session {
     reader: LineReader,
-    reporting: bool,
-    report_pending: [bool; CHANNELS],
 }
 
 impl Default for Session {
@@ -67,43 +64,11 @@ impl Session {
     pub fn new() -> Self {
         Session {
             reader: LineReader::new(),
-            reporting: false,
-            report_pending: [false; CHANNELS],
         }
     }
 
     pub fn reset(&mut self) {
         self.reader = LineReader::new();
-        self.reporting = false;
-        self.report_pending = [false; CHANNELS];
-    }
-
-    pub fn reporting(&self) -> bool {
-        self.reporting
-    }
-
-    pub fn set_report_pending(&mut self, channel: usize) {
-        if self.reporting {
-            self.report_pending[channel] = true;
-        }
-    }
-
-    pub fn is_report_pending(&self) -> Option<usize> {
-        if ! self.reporting {
-            None
-        } else {
-            self.report_pending.iter()
-                .enumerate()
-                .fold(None, |result, (channel, report_pending)| {
-                    result.or_else(|| {
-                        if *report_pending { Some(channel) } else { None }
-                    })
-                })
-        }
-    }
-
-    pub fn mark_report_sent(&mut self, channel: usize) {
-        self.report_pending[channel] = false;
     }
 
     pub fn feed(&mut self, buf: &[u8]) -> (usize, SessionInput) {
@@ -114,12 +79,6 @@ impl Session {
             match line {
                 Some(line) => {
                     let command = Command::parse(&line);
-                    match command {
-                        Ok(Command::Reporting(reporting)) => {
-                            self.reporting = reporting;
-                        }
-                        _ => {}
-                    }
                     return (buf_bytes, command.into());
                 }
                 None => {}