README: Document units in clamped PWM value

Show in PwmSummary the set value, before all PWM duty calculations
instead of the machine value after the calculations. Also save the set
value into the flash store instead of the machine value.

README.md

@@ -98,10 +98,10 @@ formatted as line-delimited JSON.
 | `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                                           |
-| `pwm <0/1> max_v <volt>`                   | Set maximum output voltage                                                    |
-| `pwm <0/1> i_set <amp>`                    | Disengage PID, set fixed output current                                       |
+| `pwm <0/1> max_i_pos <amp>`                | Set maximum positive output current, clamped to [0 A, 2 A]                    |
+| `pwm <0/1> max_i_neg <amp>`                | Set maximum negative output current, clamped to [0 A, 2 A]                    |
+| `pwm <0/1> max_v <volt>`                   | Set maximum output voltage, clamped to [0 V, 4 V]                             |
+| `pwm <0/1> i_set <amp>`                    | Disengage PID, set fixed output current, clamped to [-2 A, 2 A]               |
 | `pwm <0/1> polarity <normal/reversed>`     | Set output current polarity, with 'normal' being the front panel polarity     |
 | `pwm <0/1> pid`                            | Let output current to be controlled by the PID                                |
 | `center <0/1> <volt>`                      | Set the MAX1968 0A-centerpoint to the specified fixed voltage                 |

pytec/pytec/client.py

@@ -16,7 +16,7 @@ class Client:
         pwm_report = self.get_pwm()
         for pwm_channel in pwm_report:
             for limit in ["max_i_neg", "max_i_pos", "max_v"]:
-                if pwm_channel[limit]["value"] == 0.0:
+                if pwm_channel[limit] == 0.0:
                     logging.warning("`{}` limit is set to zero on channel {}".format(limit, pwm_channel["channel"]))
 
     def _read_line(self):
@@ -53,17 +53,17 @@ class Client:
         Example::
             [{'channel': 0,
               'center': 'vref',
-              'i_set': {'max': 2.9802790335151985, 'value': -0.02002179650216762},
-              'max_i_neg': {'max': 3.0, 'value': 3.0},
-              'max_v': {'max': 5.988, 'value': 5.988},
-              'max_i_pos': {'max': 3.0, 'value': 3.0}},
+              'i_set': -0.02002179650216762,
+              'max_i_neg': 2.0,
+              'max_v': 3.988,
+              'max_i_pos': 2.0,
               'polarity': 'normal',
              {'channel': 1,
               'center': 'vref',
-              'i_set': {'max': 2.9802790335151985, 'value': -0.02002179650216762},
-              'max_i_neg': {'max': 3.0, 'value': 3.0},
-              'max_v': {'max': 5.988, 'value': 5.988},
-              'max_i_pos': {'max': 3.0, 'value': 3.0}}
+              'i_set': -0.02002179650216762,
+              'max_i_neg': 2.0,
+              'max_v': 3.988,
+              'max_i_pos': 2.0}
               'polarity': 'normal',
             ]
         """

src/channel_state.rs

@@ -16,6 +16,7 @@ use uom::si::{
 use crate::{
     ad7172,
     pid,
+    config::PwmLimits,
     steinhart_hart as sh,
     command_parser::{CenterPoint, Polarity},
 };
@@ -32,6 +33,7 @@ pub struct ChannelState {
     pub center: CenterPoint,
     pub dac_value: ElectricPotential,
     pub i_set: ElectricCurrent,
+    pub pwm_limits: PwmLimits,
     pub pid_engaged: bool,
     pub pid: pid::Controller,
     pub sh: sh::Parameters,
@@ -49,6 +51,11 @@ impl ChannelState {
             center: CenterPoint::Vref,
             dac_value: ElectricPotential::new::<volt>(0.0),
             i_set: ElectricCurrent::new::<ampere>(0.0),
+            pwm_limits: PwmLimits {
+                max_v: 0.0,
+                max_i_pos: 0.0,
+                max_i_neg: 0.0,
+            },
             pid_engaged: false,
             pid: pid::Controller::new(pid::Parameters::default()),
             sh: sh::Parameters::default(),

src/channels.rs

@@ -357,52 +357,16 @@ impl Channels {
         }
     }
 
-    fn get_pwm(&self, channel: usize, pin: PwmPin) -> f64 {
-        fn get<P: hal::PwmPin<Duty=u16>>(pin: &P) -> f64 {
-            let duty = pin.get_duty();
-            let max = pin.get_max_duty();
-            duty as f64 / (max as f64)
-        }
-        match (channel, pin) {
-            (_, PwmPin::ISet) =>
-                panic!("i_set is no pwm pin"),
-            (0, PwmPin::MaxIPos) =>
-                get(&self.pwm.max_i_pos0),
-            (0, PwmPin::MaxINeg) =>
-                get(&self.pwm.max_i_neg0),
-            (0, PwmPin::MaxV) =>
-                get(&self.pwm.max_v0),
-            (1, PwmPin::MaxIPos) =>
-                get(&self.pwm.max_i_pos1),
-            (1, PwmPin::MaxINeg) =>
-                get(&self.pwm.max_i_neg1),
-            (1, PwmPin::MaxV) =>
-                get(&self.pwm.max_v1),
-            _ =>
-                unreachable!(),
-        }
+    pub fn get_max_v(&mut self, channel: usize) -> ElectricPotential {
+        ElectricPotential::new::<volt>(self.channel_state(channel).pwm_limits.max_v)
     }
 
-    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, MAX_TEC_V)
+    pub fn get_max_i_pos(&mut self, channel: usize) -> ElectricCurrent {
+        ElectricCurrent::new::<ampere>(self.channel_state(channel).pwm_limits.max_i_pos)
     }
 
-    pub fn get_max_i_pos(&mut self, channel: usize) -> (ElectricCurrent, ElectricCurrent) {
-        let duty = match self.channel_state(channel).polarity {
-            Polarity::Normal => self.get_pwm(channel, PwmPin::MaxIPos),
-            Polarity::Reversed => self.get_pwm(channel, PwmPin::MaxINeg),
-        };
-        (duty * MAX_TEC_I_DUTY_TO_CURRENT_RATE, MAX_TEC_I)
-    }
-
-    pub fn get_max_i_neg(&mut self, channel: usize) -> (ElectricCurrent, ElectricCurrent) {
-        let duty = match self.channel_state(channel).polarity {
-            Polarity::Normal => self.get_pwm(channel, PwmPin::MaxINeg),
-            Polarity::Reversed => self.get_pwm(channel, PwmPin::MaxIPos),
-        };
-        (duty * MAX_TEC_I_DUTY_TO_CURRENT_RATE, MAX_TEC_I)
+    pub fn get_max_i_neg(&mut self, channel: usize) -> ElectricCurrent {
+        ElectricCurrent::new::<ampere>(self.channel_state(channel).pwm_limits.max_i_neg)
     }
 
     // Get current passing through TEC
@@ -448,36 +412,42 @@ 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 max_v = max_v.min(MAX_TEC_V).max(ElectricPotential::zero());
+        let duty = (max_v / max).get::<ratio>();
         let duty = self.set_pwm(channel, PwmPin::MaxV, duty);
+        self.channel_state(channel).pwm_limits.max_v = max_v.get::<volt>();
         (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_TEC_I_DUTY_TO_CURRENT_RATE).get::<ratio>();
+        let max_i_pos = max_i_pos.min(MAX_TEC_I).max(ElectricCurrent::zero());
+        let duty = (max_i_pos / MAX_TEC_I_DUTY_TO_CURRENT_RATE).get::<ratio>();
         let duty = match self.channel_state(channel).polarity {
             Polarity::Normal => self.set_pwm(channel, PwmPin::MaxIPos, duty),
             Polarity::Reversed => self.set_pwm(channel, PwmPin::MaxINeg, duty),
         };
+        self.channel_state(channel).pwm_limits.max_i_pos = max_i_pos.get::<ampere>();
         (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.min(MAX_TEC_I).max(ElectricCurrent::zero()) / MAX_TEC_I_DUTY_TO_CURRENT_RATE).get::<ratio>();
+        let max_i_neg = max_i_neg.min(MAX_TEC_I).max(ElectricCurrent::zero());
+        let duty = (max_i_neg / MAX_TEC_I_DUTY_TO_CURRENT_RATE).get::<ratio>();
         let duty = match self.channel_state(channel).polarity {
             Polarity::Normal => self.set_pwm(channel, PwmPin::MaxINeg, duty),
             Polarity::Reversed => self.set_pwm(channel, PwmPin::MaxIPos, duty),
         };
+        self.channel_state(channel).pwm_limits.max_i_neg = max_i_neg.get::<ampere>();
         (duty * MAX_TEC_I_DUTY_TO_CURRENT_RATE, max)
     }
 
     pub fn set_polarity(&mut self, channel: usize, polarity: Polarity) {
         if self.channel_state(channel).polarity != polarity {
             let i_set = self.channel_state(channel).i_set;
-            let max_i_pos = self.get_max_i_pos(channel).0;
-            let max_i_neg = self.get_max_i_neg(channel).0;
+            let max_i_pos = self.get_max_i_pos(channel);
+            let max_i_neg = self.get_max_i_neg(channel);
             self.channel_state(channel).polarity = polarity;
 
             self.set_i(channel, i_set);
@@ -541,10 +511,10 @@ impl Channels {
         PwmSummary {
             channel,
             center: CenterPointJson(self.channel_state(channel).center.clone()),
-            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(),
+            i_set: self.get_i(channel),
+            max_v: self.get_max_v(channel),
+            max_i_pos: self.get_max_i_pos(channel),
+            max_i_neg: self.get_max_i_neg(channel),
             polarity: PolarityJson(self.channel_state(channel).polarity.clone()),
         }
     }
@@ -642,26 +612,14 @@ impl Serialize for PolarityJson {
     }
 }
 
-#[derive(Serialize)]
-pub struct PwmSummaryField<T: Serialize> {
-    value: T,
-    max: T,
-}
-
-impl<T: Serialize> From<(T, T)> for PwmSummaryField<T> {
-    fn from((value, max): (T, T)) -> Self {
-        PwmSummaryField { value, max }
-    }
-}
-
 #[derive(Serialize)]
 pub struct PwmSummary {
     channel: usize,
     center: CenterPointJson,
-    i_set: PwmSummaryField<ElectricCurrent>,
-    max_v: PwmSummaryField<ElectricPotential>,
-    max_i_pos: PwmSummaryField<ElectricCurrent>,
-    max_i_neg: PwmSummaryField<ElectricCurrent>,
+    i_set: ElectricCurrent,
+    max_v: ElectricPotential,
+    max_i_pos: ElectricCurrent,
+    max_i_neg: ElectricCurrent,
     polarity: PolarityJson,
 }
 

src/config.rs

@@ -75,17 +75,17 @@ impl ChannelConfig {
 }
 
 #[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
-struct PwmLimits {
-    max_v: f64,
-    max_i_pos: f64,
-    max_i_neg: f64,
+pub struct PwmLimits {
+    pub max_v: f64,
+    pub max_i_pos: f64,
+    pub max_i_neg: f64,
 }
 
 impl PwmLimits {
     pub fn new(channels: &mut Channels, channel: usize) -> Self {
-        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);
+        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 {
             max_v: max_v.get::<volt>(),
             max_i_pos: max_i_pos.get::<ampere>(),