PwmLimits: Save user set value into flash

In place of the machine values derived from the PWM duty / center point
calculations

README.md

@@ -100,10 +100,10 @@ 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_pos <amp>`      | Set maximum positive output current, clamped at [0, 2]                        |
-| `pwm <0/1> max_i_neg <amp>`      | Set maximum negative output current                                           |
+| `pwm <0/1> max_i_neg <amp>`      | Set maximum negative output current, clamped at [0, 2]                        |
-| `pwm <0/1> max_v <volt>`         | Set maximum output voltage                                                    |
+| `pwm <0/1> max_v <volt>`         | Set maximum output voltage, clamped at [0, 4]                                 |
-| `pwm <0/1> i_set <amp>`          | Disengage PID, set fixed output current                                       |
+| `pwm <0/1> i_set <amp>`          | Disengage PID, set fixed output current, clamped at [-2, 2]                   |
 | `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                 |
 | `center <0/1> vref`              | Set the MAX1968 0A-centerpoint to measure from VREF                           |

src/channel_state.rs

@@ -16,6 +16,7 @@ use uom::si::{
 use crate::{
     ad7172,
     pid,
+    config::PwmLimits,
     steinhart_hart as sh,
     command_parser::CenterPoint,
 };
@@ -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,
@@ -48,6 +50,11 @@ 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

@@ -390,19 +390,19 @@ impl Channels {
     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)
+        (duty * max, ElectricPotential::new::<volt>(self.channel_state(channel).pwm_limits.max_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_TEC_I)
+        (duty * max, ElectricCurrent::new::<ampere>(self.channel_state(channel).pwm_limits.max_i_pos))
     }
 
     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, ElectricCurrent::new::<ampere>(self.channel_state(channel).pwm_limits.max_i_neg))
     }
 
     // Get current passing through TEC
@@ -446,6 +446,7 @@ impl Channels {
         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 = self.set_pwm(channel, PwmPin::MaxV, duty);
+        self.channel_state(channel).pwm_limits.max_v = max_v.get::<volt>();
         (duty * max, max)
     }
 
@@ -453,6 +454,7 @@ impl Channels {
         let max = ElectricCurrent::new::<ampere>(3.0);
         let duty = (max_i_pos.min(MAX_TEC_I).max(ElectricCurrent::zero()) / max).get::<ratio>();
         let duty = self.set_pwm(channel, PwmPin::MaxIPos, duty);
+        self.channel_state(channel).pwm_limits.max_i_pos = max_i_pos.get::<ampere>();
         (duty * max, max)
     }
 
@@ -460,6 +462,7 @@ impl Channels {
         let max = ElectricCurrent::new::<ampere>(3.0);
         let duty = (max_i_neg.min(MAX_TEC_I).max(ElectricCurrent::zero()) / max).get::<ratio>();
         let duty = self.set_pwm(channel, PwmPin::MaxINeg, duty);
+        self.channel_state(channel).pwm_limits.max_i_neg = max_i_neg.get::<ampere>();
         (duty * max, max)
     }
 
@@ -518,7 +521,7 @@ 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), self.channel_state(channel).i_set).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(),
@@ -606,12 +609,12 @@ impl Serialize for CenterPointJson {
 #[derive(Serialize)]
 pub struct PwmSummaryField<T: Serialize> {
     value: T,
-    max: T,
+    set_value: T,
 }
 
 impl<T: Serialize> From<(T, T)> for PwmSummaryField<T> {
-    fn from((value, max): (T, T)) -> Self {
+    fn from((value, set_value): (T, T)) -> Self {
-        PwmSummaryField { value, max }
+        PwmSummaryField { value, set_value }
     }
 }
 

src/config.rs

@@ -72,17 +72,17 @@ impl ChannelConfig {
 }
 
 #[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
-struct PwmLimits {
+pub struct PwmLimits {
-    max_v: f64,
+    pub max_v: f64,
-    max_i_pos: f64,
+    pub max_i_pos: f64,
-    max_i_neg: 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_v) = channels.get_max_v(channel);
-        let (max_i_pos, _) = channels.get_max_i_pos(channel);
+        let (_, max_i_pos) = channels.get_max_i_pos(channel);
-        let (max_i_neg, _) = channels.get_max_i_neg(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>(),