TCP Command: pwm -> output

Current limit pins are driven by PWM inputs to the MAX1968 driver, but
this is an implementation detail, and should not be exposed in the form
of the command interface. Rename it to "output" in all instances.

See M-Labs/thermostat#62 (comment).

.gitignore

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

README.md

@@ -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
@@ -95,16 +93,15 @@ Send commands as simple text string terminated by `\n`. Responses are
 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                                           |
-| `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> pid`                  | Let output current to be controlled by the PID                                |
+| `output`                                  | Show current output settings                                                  |
+| `output <0/1> max_i_pos <amp>`            | Set maximum positive output current, clamped to [0, 2]                        |
+| `output <0/1> max_i_neg <amp>`            | Set maximum negative output current, clamped to [0, 2]                        |
+| `output <0/1> max_v <volt>`               | Set maximum output voltage, clamped to [0, 4]                                 |
+| `output <0/1> i_set <amp>`                | Disengage PID, set fixed output current, clamped to [-2, 2]                   |
+| `output <0/1> polarity <normal/reversed>` | Set output current polarity, with 'normal' being the front panel polarity     |
+| `output <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                           |
 | `pid`                                     | Show PID configuration                                                        |
@@ -186,6 +183,8 @@ postfilter rate can be tuned with the `postfilter` command.
 
 When using a TEC module with the Thermostat, the Thermostat expects the thermal load (where the thermistor is located) to cool down with a positive software current set point, and heat up with a negative current set point.
 
+If the Thermostat is used for temperature control with the Sinara 5432 DAC "Zotino", and is connected via an IDC cable, the TEC polarity may need to be reversed with the `pwm <ch> polarity reversed` TCP command.
+
 Testing heat flow direction with a low set current is recommended before installation of the TEC module.
 
 ### Limits
@@ -193,7 +192,7 @@ Testing heat flow direction with a low set current is recommended before install
 Each of the MAX1968 TEC driver has analog/PWM inputs for setting
 output limits.
 
-Use the `pwm` command to see current settings and maximum values.
+Use the `output` command to see current settings and maximum values.
 
 | Limit       | Unit    | Description                   |
 | ---         | :---:   | ---                           |
@@ -204,28 +203,28 @@ Use the `pwm` command to see current settings and maximum values.
 
 Example: set the maximum voltage of channel 0 to 1.5 V.
 ```
-pwm 0 max_v 1.5
+output 0 max_v 1.5
 ```
 
 Example: set the maximum negative current of channel 0 to -3 A.
 ```
-pwm 0 max_i_neg 3
+output 0 max_i_neg 3
 ```
 
 Example: set the maximum positive current of channel 1 to 3 A.
 ```
-pwm 0 max_i_pos 3
+output 0 max_i_pos 3
 ```
 
 ### Open-loop mode
 
 To manually control TEC output current, omit the limit parameter of
-the `pwm` command. Doing so will disengage the PID control for that
+the `output` command. Doing so will disengage the PID control for that
 channel.
 
 Example: set output current of channel 0 to 0 A.
 ```
-pwm 0 i_set 0
+output 0 i_set 0
 ```
 
 ## PID-stabilized temperature control
@@ -238,7 +237,7 @@ pid 0 target 20
 Enter closed-loop mode by switching control of the TEC output current
 of channel 0 to the PID algorithm:
 ```
-pwm 0 pid
+output 0 pid
 ```
 
 ## LED indicators
@@ -251,8 +250,7 @@ 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                                          |

flake.nix

@@ -63,7 +63,7 @@
         name = "thermostat-dev-shell";
         packages = with pkgs; [
           rust llvm
-          openocd dfu-util
+          openocd dfu-util rlwrap
           ] ++ (with python3Packages; [
             numpy matplotlib
           ]);

pytec/autotune.py

@@ -253,9 +253,9 @@ def main():
 
         tuner_out = tuner.output()
 
-        tec.set_param("pwm", channel, "i_set", tuner_out)
+        tec.set_param("output", channel, "i_set", tuner_out)
 
-    tec.set_param("pwm", channel, "i_set", 0)
+    tec.set_param("output", channel, "i_set", 0)
 
 
 if __name__ == "__main__":

pytec/example.py

@@ -2,9 +2,9 @@ from pytec.client import Client
 
 tec = Client() #(host="localhost", port=6667)
 tec.set_param("s-h", 1, "t0", 20)
-print(tec.get_pwm())
+print(tec.get_output())
 print(tec.get_pid())
-print(tec.get_pwm())
+print(tec.get_output())
 print(tec.get_postfilter())
 print(tec.get_steinhart_hart())
 for data in tec.report_mode():

pytec/pytec/client.py

@@ -1,6 +1,7 @@
 import socket
 import json
 import logging
+import time
 
 class CommandError(Exception):
     pass
@@ -12,11 +13,11 @@ class Client:
         self._check_zero_limits()
 
     def _check_zero_limits(self):
-        pwm_report = self.get_pwm()
-        for pwm_channel in pwm_report:
+        output_report = self.get_output()
+        for output_channel in output_report:
             for limit in ["max_i_neg", "max_i_pos", "max_v"]:
-                if pwm_channel[limit]["value"] == 0.0:
-                    logging.warning("`{}` limit is set to zero on channel {}".format(limit, pwm_channel["channel"]))
+                if output_channel[limit] == 0.0:
+                    logging.warning("`{}` limit is set to zero on channel {}".format(limit, output_channel["channel"]))
 
     def _read_line(self):
         # read more lines
@@ -46,25 +47,27 @@ class Client:
             result[int(item["channel"])] = item
         return result
 
-    def get_pwm(self):
-        """Retrieve PWM limits for the TEC
+    def get_output(self):
+        """Retrieve output limits for the TEC
 
         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',
             ]
         """
-        return self._get_conf("pwm")
+        return self._get_conf("output")
 
     def get_pid(self):
         """Retrieve PID control state
@@ -126,9 +129,8 @@ 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
@@ -136,12 +138,13 @@ 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
 
         Examples::
-            tec.set_param("pwm", 0, "max_v", 2.0)
+            tec.set_param("output", 0, "max_v", 2.0)
             tec.set_param("pid", 1, "output_max", 2.5)
             tec.set_param("s-h", 0, "t0", 20.0)
             tec.set_param("center", 0, "vref")
@@ -158,7 +161,7 @@ class Client:
     def power_up(self, channel, target):
         """Start closed-loop mode"""
         self.set_param("pid", channel, "target", value=target)
-        self.set_param("pwm", channel, "pid")
+        self.set_param("output", channel, "pid")
 
     def save_config(self):
         """Save current configuration to EEPROM"""

src/channel_state.rs

@@ -16,8 +16,9 @@ use uom::si::{
 use crate::{
     ad7172,
     pid,
+    config::PwmLimits,
     steinhart_hart as sh,
-    command_parser::CenterPoint,
+    command_parser::{CenterPoint, Polarity},
 };
 
 const R_INNER: f64 = 2.0 * 5100.0;
@@ -32,9 +33,11 @@ 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,
+    pub polarity: Polarity,
 }
 
 impl ChannelState {
@@ -48,9 +51,15 @@ 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(),
+            polarity: Polarity::Normal,
         }
     }
 

src/channels.rs

@@ -17,11 +17,12 @@ use crate::{
     ad7172,
     channel::{Channel, Channel0, Channel1},
     channel_state::ChannelState,
-    command_parser::{CenterPoint, PwmPin},
+    command_parser::{CenterPoint, PwmPin, Polarity},
     command_handler::JsonBuffer,
     pins::{self, Channel0VRef, Channel1VRef},
     steinhart_hart,
 };
+use crate::timer::sleep;
 
 pub enum PinsAdcReadTarget {
     VREF,
@@ -44,7 +45,11 @@ pub const MAX_TEC_V: ElectricPotential = ElectricPotential {
     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,
@@ -153,6 +158,11 @@ impl Channels {
 
     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);
+        self.channel_state(channel).i_set = i_set;
+        let negate = match self.channel_state(channel).polarity {
+            Polarity::Normal => 1.0,
+            Polarity::Reversed => -1.0,
+        };
         let vref_meas = match channel.into() {
             0 => self.channel0.vref_meas,
             1 => self.channel1.vref_meas,
@@ -160,10 +170,9 @@ 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 = negate * i_set * 10.0 * r_sense + center_point;
         let voltage = self.set_dac(channel, voltage);
-        let i_set = (voltage - center_point) / (10.0 * r_sense);
-        self.channel_state(channel).i_set = i_set;
+        let i_set = negate * (voltage - center_point) / (10.0 * r_sense);
         i_set
     }
 
@@ -269,17 +278,6 @@ impl Channels {
         }
     }
 
-    pub fn read_dac_feedback_until_stable(&mut self, channel: usize, tolerance: ElectricPotential) -> ElectricPotential {
-        let mut prev = self.adc_read(channel, PinsAdcReadTarget::DacVfb, 1);
-        loop {
-            let current = self.adc_read(channel, PinsAdcReadTarget::DacVfb, 1);
-            if (current - prev).abs() < tolerance {
-                return current;
-            }
-            prev = current;
-        }
-    }
-
     /// 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.
@@ -306,8 +304,7 @@ impl Channels {
         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 => {
@@ -318,14 +315,15 @@ impl Channels {
                     }
                     _ => 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) * DAC_OUT_V_MAX;
                     match channel {
@@ -334,8 +332,6 @@ impl Channels {
                         _ => unreachable!(),
                     }
                 }
-
-                prev_value = value;
             }
         }
 
@@ -361,53 +357,25 @@ 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 max = ElectricCurrent::new::<ampere>(3.0);
-        let duty = self.get_pwm(channel, PwmPin::MaxIPos);
-        (duty * max, 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_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
     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)
+        let tec_i = (self.adc_read(channel, PinsAdcReadTarget::ITec, 16) - self.adc_read(channel, PinsAdcReadTarget::VREF, 16)) / ElectricalResistance::new::<ohm>(0.4);
+        match self.channel_state(channel).polarity {
+            Polarity::Normal => tec_i,
+            Polarity::Reversed => -tec_i,
+        }
     }
 
     // Get voltage across TEC
@@ -444,23 +412,48 @@ 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).get::<ratio>();
-        let duty = self.set_pwm(channel, PwmPin::MaxIPos, duty);
-        (duty * max, max)
+        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).get::<ratio>();
-        let duty = self.set_pwm(channel, PwmPin::MaxINeg, duty);
-        (duty * max, max)
+        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);
+            let max_i_neg = self.get_max_i_neg(channel);
+            self.channel_state(channel).polarity = polarity;
+
+            self.set_i(channel, i_set);
+            self.set_max_i_pos(channel, max_i_pos);
+            self.set_max_i_neg(channel, max_i_neg);
+        }
     }
 
     fn report(&mut self, channel: usize) -> Report {
@@ -514,21 +507,22 @@ impl Channels {
         false
     }
 
-    fn pwm_summary(&mut self, channel: usize) -> PwmSummary {
-        PwmSummary {
+    fn output_summary(&mut self, channel: usize) -> OutputSummary {
+        OutputSummary {
             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()),
         }
     }
 
-    pub fn pwm_summaries_json(&mut self) -> Result<JsonBuffer, serde_json_core::ser::Error> {
+    pub fn output_summaries_json(&mut self) -> Result<JsonBuffer, serde_json_core::ser::Error> {
         let mut summaries = Vec::<_, U2>::new();
         for channel in 0..CHANNELS {
-            let _ = summaries.push(self.pwm_summary(channel));
+            let _ = summaries.push(self.output_summary(channel));
         }
         serde_json_core::to_vec(&summaries)
     }
@@ -603,26 +597,30 @@ impl Serialize for CenterPointJson {
     }
 }
 
-#[derive(Serialize)]
-pub struct PwmSummaryField<T: Serialize> {
-    value: T,
-    max: T,
-}
+pub struct PolarityJson(Polarity);
 
-impl<T: Serialize> From<(T, T)> for PwmSummaryField<T> {
-    fn from((value, max): (T, T)) -> Self {
-        PwmSummaryField { value, max }
+// used in JSON encoding, not for config
+impl Serialize for PolarityJson {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        serializer.serialize_str(match self.0 {
+            Polarity::Normal => "normal",
+            Polarity::Reversed => "reversed",
+        })
     }
 }
 
 #[derive(Serialize)]
-pub struct PwmSummary {
+pub struct OutputSummary {
     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,
 }
 
 #[derive(Serialize)]

src/command_handler.rs

@@ -11,7 +11,8 @@ use super::{
         CenterPoint, 
         PidParameter, 
         PwmPin, 
-        ShParameter
+        ShParameter,
+        Polarity
     },
     ad7172,
     CHANNEL_CONFIG_KEY,
@@ -22,7 +23,6 @@ use super::{
     config::ChannelConfig,
     dfu,
     flash_store::FlashStore,
-    session::Session,
     FanCtrl,
     hw_rev::HWRev,
 };
@@ -87,16 +87,6 @@ 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) => {
@@ -126,7 +116,7 @@ impl Handler {
     }
 
     fn show_pwm(socket: &mut TcpSocket, channels: &mut Channels) -> Result<Handler, Error> {
-        match channels.pwm_summaries_json() {
+        match channels.output_summaries_json() {
             Ok(buf) => {
                 send_line(socket, &buf);
             }
@@ -181,6 +171,12 @@ impl Handler {
         Ok(Handler::Handled)
     }
 
+    fn set_polarity(socket: &mut TcpSocket, channels: &mut Channels, channel: usize, polarity: Polarity) -> Result<Handler, Error> {
+        channels.set_polarity(channel, polarity);
+        send_line(socket, b"{}");
+        Ok(Handler::Handled)
+    }
+
     fn set_pwm (socket: &mut TcpSocket, channels: &mut Channels, channel: usize, pin: PwmPin, value: f64) -> Result<Handler, Error> {
         match pin {
             PwmPin::ISet => {
@@ -412,19 +408,18 @@ 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),
+            Command::Show(ShowCommand::Output) => Handler::show_pwm(socket, channels),
             Command::Show(ShowCommand::SteinhartHart) => Handler::show_steinhart_hart(socket, channels),
             Command::Show(ShowCommand::PostFilter) => Handler::show_post_filter(socket, channels),
             Command::Show(ShowCommand::Ipv4) => Handler::show_ipv4(socket, ipv4_config),
-            Command::PwmPid { channel } => Handler::engage_pid(socket, channels, channel),
-            Command::Pwm { channel, pin, value } => Handler::set_pwm(socket, channels, channel, pin, value),
+            Command::OutputPid { channel } => Handler::engage_pid(socket, channels, channel),
+            Command::OutputPolarity { channel, polarity } => Handler::set_polarity(socket, channels, channel, polarity),
+            Command::Output { channel, pin, value } => Handler::set_pwm(socket, channels, channel, pin, value),
             Command::CenterPoint { channel, center } => Handler::set_center_point(socket, channels, channel, center),
             Command::Pid { channel, parameter, value } => Handler::set_pid(socket, channels, channel, parameter, value),
             Command::SteinhartHart { channel, parameter, value } => Handler::set_steinhart_hart(socket, channels, channel, parameter, value),

src/command_parser.rs

@@ -96,8 +96,7 @@ pub struct Ipv4Config {
 #[derive(Debug, Clone, PartialEq)]
 pub enum ShowCommand {
     Input,
-    Reporting,
-    Pwm,
+    Output,
     Pid,
     SteinhartHart,
     PostFilter,
@@ -136,6 +135,12 @@ pub enum CenterPoint {
     Override(f32),
 }
 
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub enum Polarity {
+    Normal,
+    Reversed,
+}
+
 #[derive(Debug, Clone, PartialEq)]
 pub enum Command {
     Quit,
@@ -148,17 +153,20 @@ pub enum Command {
     Reset,
     Ipv4(Ipv4Config),
     Show(ShowCommand),
-    Reporting(bool),
     /// PWM parameter setting
-    Pwm {
+    Output {
         channel: usize,
         pin: PwmPin,
         value: f64,
     },
     /// Enable PID control for `i_set`
-    PwmPid {
+    OutputPid {
         channel: usize,
     },
+    OutputPolarity {
+        channel: usize,
+        polarity: Polarity,
+    },
     CenterPoint {
         channel: usize,
         center: CenterPoint,
@@ -233,12 +241,6 @@ 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 +248,8 @@ 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)
-        ))
     )(input)
 }
 
@@ -316,13 +302,25 @@ fn pwm_setup(input: &[u8]) -> IResult<&[u8], Result<(PwmPin, f64), Error>> {
     )(input)
 }
 
-/// `pwm <0-1> pid` - Set PWM to be controlled by PID
-fn pwm_pid(input: &[u8]) -> IResult<&[u8], ()> {
+/// `output <0-1> pid` - Set output to be controlled by PID
+fn output_pid(input: &[u8]) -> IResult<&[u8], ()> {
     value((), tag("pid"))(input)
 }
 
-fn pwm(input: &[u8]) -> IResult<&[u8], Result<Command, Error>> {
-    let (input, _) = tag("pwm")(input)?;
+fn pwm_polarity(input: &[u8]) -> IResult<&[u8], Polarity> {
+    preceded(
+        tag("polarity"),
+        preceded(
+            whitespace,
+            alt((value(Polarity::Normal, tag("normal")),
+                 value(Polarity::Reversed, tag("reversed"))
+            ))
+        )
+    )(input)
+}
+
+fn output(input: &[u8]) -> IResult<&[u8], Result<Command, Error>> {
+    let (input, _) = tag("output")(input)?;
     alt((
         |input| {
             let (input, _) = whitespace(input)?;
@@ -330,14 +328,18 @@ fn pwm(input: &[u8]) -> IResult<&[u8], Result<Command, Error>> {
             let (input, _) = whitespace(input)?;
             let (input, result) = alt((
                 |input| {
-                    let (input, ()) = pwm_pid(input)?;
-                    Ok((input, Ok(Command::PwmPid { channel })))
+                    let (input, ()) = output_pid(input)?;
+                    Ok((input, Ok(Command::OutputPid { channel })))
+                },
+                |input| {
+                    let (input, polarity) = pwm_polarity(input)?;
+                    Ok((input, Ok(Command::OutputPolarity { channel, polarity })))
                 },
                 |input| {
                     let (input, config) = pwm_setup(input)?;
                     match config {
                         Ok((pin, value)) =>
-                            Ok((input, Ok(Command::Pwm { channel, pin, value }))),
+                            Ok((input, Ok(Command::Output { channel, pin, value }))),
                         Err(e) =>
                             Ok((input, Err(e))),
                     }
@@ -346,7 +348,7 @@ fn pwm(input: &[u8]) -> IResult<&[u8], Result<Command, Error>> {
             end(input)?;
             Ok((input, result))
         },
-        value(Ok(Command::Show(ShowCommand::Pwm)), end)
+        value(Ok(Command::Show(ShowCommand::Output)), end)
     ))(input)
 }
 
@@ -591,7 +593,7 @@ fn command(input: &[u8]) -> IResult<&[u8], Result<Command, Error>> {
          value(Ok(Command::Reset), tag("reset")),
          ipv4,
          map(report, Ok),
-         pwm,
+         output,
          center_point,
          pid,
          steinhart_hart,
@@ -682,46 +684,37 @@ 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");
-        assert_eq!(command, Ok(Command::Pwm {
+        let command = Command::parse(b"output 1 i_set 16383");
+        assert_eq!(command, Ok(Command::Output {
             channel: 1,
             pin: PwmPin::ISet,
             value: 16383.0,
         }));
     }
 
+    #[test]
+    fn parse_pwm_polarity() {
+        let command = Command::parse(b"pwm 0 polarity reversed");
+        assert_eq!(command, Ok(Command::PwmPolarity {
+            channel: 0,
+            polarity: Polarity::Reversed,
+        }));
+    }
+
     #[test]
     fn parse_pwm_pid() {
-        let command = Command::parse(b"pwm 0 pid");
-        assert_eq!(command, Ok(Command::PwmPid {
+        let command = Command::parse(b"output 0 pid");
+        assert_eq!(command, Ok(Command::OutputPid {
             channel: 0,
         }));
     }
 
     #[test]
     fn parse_pwm_max_i_pos() {
-        let command = Command::parse(b"pwm 0 max_i_pos 7");
-        assert_eq!(command, Ok(Command::Pwm {
+        let command = Command::parse(b"output 0 max_i_pos 7");
+        assert_eq!(command, Ok(Command::Output {
             channel: 0,
             pin: PwmPin::MaxIPos,
             value: 7.0,
@@ -730,8 +723,8 @@ mod test {
 
     #[test]
     fn parse_pwm_max_i_neg() {
-        let command = Command::parse(b"pwm 0 max_i_neg 128");
-        assert_eq!(command, Ok(Command::Pwm {
+        let command = Command::parse(b"output 0 max_i_neg 128");
+        assert_eq!(command, Ok(Command::Output {
             channel: 0,
             pin: PwmPin::MaxINeg,
             value: 128.0,
@@ -740,8 +733,8 @@ mod test {
 
     #[test]
     fn parse_pwm_max_v() {
-        let command = Command::parse(b"pwm 0 max_v 32768");
-        assert_eq!(command, Ok(Command::Pwm {
+        let command = Command::parse(b"output 0 max_v 32768");
+        assert_eq!(command, Ok(Command::Output {
             channel: 0,
             pin: PwmPin::MaxV,
             value: 32768.0,

src/config.rs

@@ -8,7 +8,7 @@ use uom::si::{
 use crate::{
     ad7172::PostFilter,
     channels::Channels,
-    command_parser::CenterPoint,
+    command_parser::{CenterPoint, Polarity},
     pid,
     steinhart_hart,
 };
@@ -20,6 +20,7 @@ pub struct ChannelConfig {
     pid_target: f32,
     pid_engaged: bool,
     i_set: ElectricCurrent,
+    polarity: Polarity,
     sh: steinhart_hart::Parameters,
     pwm: PwmLimits,
     /// uses variant `PostFilter::Invalid` instead of `None` to save space
@@ -45,7 +46,8 @@ impl ChannelConfig {
             pid: state.pid.parameters.clone(),
             pid_target: state.pid.target as f32,
             pid_engaged: state.pid_engaged,
-            i_set: i_set,
+            i_set,
+            polarity: state.polarity.clone(),
             sh: state.sh.clone(),
             pwm,
             adc_postfilter,
@@ -68,21 +70,22 @@ impl ChannelConfig {
         };
         let _ = channels.adc.set_postfilter(channel as u8, adc_postfilter);
         let _ = channels.set_i(channel, self.i_set);
+        channels.set_polarity(channel, self.polarity.clone());
     }
 }
 
 #[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>(),

src/main.rs

@@ -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/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 => {}