channels: Start to make reports make sense

Names in the report make no sense, and expose implementation details.
Start simplifying the interface.

README.md

@@ -255,21 +255,18 @@ Use the bare `report` command to obtain a single report. Enable
 continuous reporting with `report mode on`. Reports are JSON objects
 with the following keys.
 
-| Key            | Unit            | Description                                          |
-| ---            | :---:           | ---                                                  |
-| `channel`      | Integer         | Channel `0`, or `1`                                  |
-| `time`         | Seconds         | Temperature measurement time                         |
-| `adc`          | Volts           | AD7172 input                                         |
-| `sens`         | Ohms            | Thermistor resistance derived from `adc`             |
-| `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                                   |
-| `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                          |
-| `tec_i`        | Amperes         | TEC output current feedback derived from `i_tec`     |
-| `tec_u_meas`   | Volts           | Measurement of the voltage across the TEC            |
-| `pid_output`   | Amperes         | PID control output                                   |
+| Key            | Unit            | Description                                    |
+| ---            | :---:           | ---                                            |
+| `channel`      | Integer         | Channel `0`, or `1`                            |
+| `time`         | Seconds         | Report timestamp (since thermostat reset)      |
+| `interval`     | Seconds         | ADC Sampling Interval                          |
+| `sens`         | Ohms            | Thermistor resistance                          |
+| `temperature`  | Degrees Celsius | Temperature derived from thermistor resistance |
+| `pid_engaged`  | Boolean         | `true` if in closed-loop mode                  |
+| `pid_output`   | Amperes         | PID control output                             |
+| `i_set`        | Amperes         | Set TEC output current                         |
+| `i_meas`       | Amperes         | Measured current passing through TEC           |
+| `v_meas`       | Volts           | Measured voltage across TEC                    |
 
 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].
 
@@ -280,10 +277,10 @@ The thermostat implements a PID control loop for each of the TEC channels, more
 ## Fan control
 
 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`.
+1. `fan` - show fan stats: `fan_pwm`, `max_abs_i_meas`, `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`.
 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`, 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 `max_abs_i_meas/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`.

src/channels.rs

@@ -405,13 +405,13 @@ impl Channels {
         (duty * max, MAX_TEC_I)
     }
 
-    // Get current passing through TEC
-    pub fn get_tec_i(&mut self, channel: usize) -> ElectricCurrent {
+    // Measure current passing through TEC
+    pub fn get_i_meas(&mut self, channel: usize) -> ElectricCurrent {
         (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 {
+    // Measure voltage across TEC
+    pub fn get_v_meas(&mut self, channel: usize) -> ElectricPotential {
         (self.adc_read(channel, PinsAdcReadTarget::VTec, 16) - ElectricPotential::new::<volt>(1.5)) * 4.0
     }
 
@@ -465,27 +465,22 @@ impl Channels {
 
     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 tec_i = self.get_tec_i(channel);
-        let dac_value = self.get_dac(channel);
+        let i_meas = self.get_i_meas(channel);
+        let v_meas = self.get_v_meas(channel);
         let state = self.channel_state(channel);
         let pid_output = ElectricCurrent::new::<ampere>(state.pid.y1);
         Report {
             channel,
             time: state.get_adc_time(),
             interval: state.get_adc_interval(),
-            adc: state.get_adc(),
             sens: state.get_sens(),
             temperature: state.get_temperature()
                 .map(|temperature| temperature.get::<degree_celsius>()),
             pid_engaged: state.pid_engaged,
-            i_set,
-            dac_value,
-            dac_feedback: self.adc_read(channel, PinsAdcReadTarget::DacVfb, 1),
-            i_tec,
-            tec_i,
-            tec_u_meas: self.get_tec_v(channel),
             pid_output,
+            i_set,
+            i_meas,
+            v_meas,
         }
     }
 
@@ -560,9 +555,9 @@ impl Channels {
         serde_json_core::to_vec(&summaries)
     }
 
-    pub fn current_abs_max_tec_i(&mut self) -> ElectricCurrent {
+    pub fn max_abs_i_meas(&mut self) -> ElectricCurrent {
         (0..CHANNELS)
-            .map(|channel| self.get_tec_i(channel).abs())
+            .map(|channel| self.get_i_meas(channel).abs())
             .max_by(|a, b| a.partial_cmp(b).unwrap_or(core::cmp::Ordering::Equal))
             .unwrap()
     }
@@ -573,17 +568,13 @@ pub struct Report {
     channel: usize,
     time: Time,
     interval: Time,
-    adc: Option<ElectricPotential>,
     sens: Option<ElectricalResistance>,
     temperature: Option<f64>,
     pid_engaged: bool,
-    i_set: ElectricCurrent,
-    dac_value: ElectricPotential,
-    dac_feedback: ElectricPotential,
-    i_tec: ElectricPotential,
-    tec_i: ElectricCurrent,
-    tec_u_meas: ElectricPotential,
     pid_output: ElectricCurrent,
+    i_set: ElectricCurrent,
+    i_meas: ElectricCurrent,
+    v_meas: ElectricPotential,
 }
 
 pub struct CenterPointJson(CenterPoint);

src/fan_ctrl.rs

@@ -27,7 +27,7 @@ pub struct FanCtrl {
     k_a: f32,
     k_b: f32,
     k_c: f32,
-    abs_max_tec_i: f32,
+    max_abs_i_meas: f32,
     hw_settings: HWSettings,
 }
 
@@ -42,7 +42,7 @@ impl FanCtrl {
             k_a: hw_settings.fan_k_a,
             k_b: hw_settings.fan_k_b,
             k_c: hw_settings.fan_k_c,
-            abs_max_tec_i: 0f32,
+            max_abs_i_meas: 0f32,
             hw_settings,
         };
         if fan_ctrl.fan_auto {
@@ -51,10 +51,10 @@ impl FanCtrl {
         fan_ctrl
     }
 
-    pub fn cycle(&mut self, abs_max_tec_i: ElectricCurrent) {
-        self.abs_max_tec_i = abs_max_tec_i.get::<ampere>() as f32;
+    pub fn cycle(&mut self, max_abs_i_meas: ElectricCurrent) {
+        self.max_abs_i_meas = max_abs_i_meas.get::<ampere>() as f32;
         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.max_abs_i_meas / 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);
@@ -65,7 +65,7 @@ impl FanCtrl {
         if self.hw_settings.fan_available {
             let summary = FanSummary {
                 fan_pwm: self.get_pwm(),
-                abs_max_tec_i: self.abs_max_tec_i,
+                abs_max_tec_i: self.max_abs_i_meas,
                 auto_mode: self.fan_auto,
                 k_a: self.k_a,
                 k_b: self.k_b,

src/main.rs

@@ -185,7 +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.max_abs_i_meas());
 
                 if channels.pid_engaged() {
                     leds.g3.on();