Move PwmLimits into its own file

The Steinhart-Hart equation was changed in code long ago to the
B-parameter equation. Rename references to it and the interface
accordingly. The `s-h` command is now `b-p`.

The reason the name "B-Parameter" equation was chosen over
"Beta-Parameter" was due to its easier searchability.

README.md

@@ -111,8 +111,8 @@ formatted as line-delimited JSON.
 | `pid <0/1> kd <value>`                    | Set differential gain                                                         |
 | `pid <0/1> output_min <amp>`              | Set mininum output                                                            |
 | `pid <0/1> output_max <amp>`              | Set maximum output                                                            |
-| `s-h`                                     | Show Steinhart-Hart equation parameters                                       |
-| `s-h <0/1> <t0/b/r0> <value>`             | Set Steinhart-Hart parameter for a channel                                    |
+| `b-p`                                     | Show B-Parameter equation parameters                                          |
+| `b-p <0/1> <t0/b/r0> <value>`             | Set B-Parameter for a channel                                                 |
 | `postfilter`                              | Show postfilter settings                                                      |
 | `postfilter <0/1> off`                    | Disable postfilter                                                            |
 | `postfilter <0/1> rate <rate>`            | Set postfilter output data rate                                               |
@@ -144,22 +144,22 @@ output will be truncated when USB buffers are full.
 
 Connect the thermistor with the SENS pins of the
 device. Temperature-depending resistance is measured by the AD7172
-ADC. To prepare conversion to a temperature, set the Beta parameters
-for the Steinhart-Hart equation.
+ADC. To prepare conversion to a temperature, set the parameters
+for the B-Parameter equation.
 
 Set the base temperature in degrees celsius for the channel 0 thermistor:
 ```
-s-h 0 t0 20
+b-p 0 t0 20
 ```
 
 Set the resistance in Ohms measured at the base temperature t0:
 ```
-s-h 0 r0 10000
+b-p 0 r0 10000
 ```
 
 Set the Beta parameter:
 ```
-s-h 0 b 3800
+b-p 0 b 3800
 ```
 
 ### 50/60 Hz filtering
@@ -260,7 +260,7 @@ with the following keys.
 | `interval`     | Seconds         | Time elapsed since last report update on channel     |
 | `adc`          | Volts           | AD7172 input                                         |
 | `sens`         | Ohms            | Thermistor resistance derived from `adc`             |
-| `temperature`  | Degrees Celsius | Steinhart-Hart conversion result derived from `sens` |
+| `temperature`  | Degrees Celsius | B-Parameter 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`                   |

pytec/example.py

@@ -1,11 +1,11 @@
 from pytec.client import Client
 
 tec = Client() #(host="localhost", port=6667)
-tec.set_param("s-h", 1, "t0", 20)
+tec.set_param("b-p", 1, "t0", 20)
 print(tec.get_output())
 print(tec.get_pid())
 print(tec.get_output())
 print(tec.get_postfilter())
-print(tec.get_steinhart_hart())
+print(tec.get_b_parameter())
 for data in tec.report_mode():
     print(data)

pytec/pytec/client.py

@@ -92,14 +92,14 @@ class Client:
         """
         return self._get_conf("pid")
 
-    def get_steinhart_hart(self):
-        """Retrieve Steinhart-Hart parameters for resistance to temperature conversion
+    def get_b_parameter(self):
+        """Retrieve B-Parameter equation parameters for resistance to temperature conversion
 
         Example::
             [{'params': {'b': 3800.0, 'r0': 10000.0, 't0': 298.15}, 'channel': 0},
              {'params': {'b': 3800.0, 'r0': 10000.0, 't0': 298.15}, 'channel': 1}]
         """
-        return self._get_conf("s-h")
+        return self._get_conf("b-p")
 
     def get_postfilter(self):
         """Retrieve DAC postfilter configuration
@@ -146,7 +146,7 @@ class Client:
         Examples::
             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("b-p", 0, "t0", 20.0)
             tec.set_param("center", 0, "vref")
             tec.set_param("postfilter", 1, 21)
 

src/b_parameter.rs

@@ -8,14 +8,14 @@ use uom::si::{
     thermodynamic_temperature::{degree_celsius, kelvin},
 };
 
-/// Steinhart-Hart equation parameters
+/// B-Parameter equation parameters
 #[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
 pub struct Parameters {
     /// Base temperature
     pub t0: ThermodynamicTemperature,
-    /// Resistance at base temperature
+    /// Thermistor resistance at base temperature
     pub r0: ElectricalResistance,
-    /// Beta
+    /// Beta (average slope of the function ln R vs. 1/T)
     pub b: TemperatureInterval,
 }
 

src/channel_state.rs

@@ -1,9 +1,8 @@
 use crate::{
-    ad7172,
+    ad7172, b_parameter as bp,
     command_parser::{CenterPoint, Polarity},
     pid,
     pwm_limits::PwmLimits,
-    steinhart_hart as sh,
 };
 use num_traits::Zero;
 use smoltcp::time::{Duration, Instant};
@@ -33,7 +32,7 @@ pub struct ChannelState {
     pub pwm_limits: PwmLimits,
     pub pid_engaged: bool,
     pub pid: pid::Controller,
-    pub sh: sh::Parameters,
+    pub bp: bp::Parameters,
     pub polarity: Polarity,
 }
 
@@ -55,7 +54,7 @@ impl ChannelState {
             },
             pid_engaged: false,
             pid: pid::Controller::new(pid::Parameters::default()),
-            sh: sh::Parameters::default(),
+            bp: bp::Parameters::default(),
             polarity: Polarity::Normal,
         }
     }
@@ -101,7 +100,7 @@ impl ChannelState {
 
     pub fn get_temperature(&self) -> Option<ThermodynamicTemperature> {
         let r = self.get_sens()?;
-        let temperature = self.sh.get_temperature(r);
+        let temperature = self.bp.get_temperature(r);
         Some(temperature)
     }
 }

src/channels.rs

@@ -1,12 +1,11 @@
 use crate::timer::sleep;
 use crate::{
-    ad5680, ad7172,
+    ad5680, ad7172, b_parameter,
     channel::{Channel, Channel0, Channel1},
     channel_state::ChannelState,
     command_handler::JsonBuffer,
     command_parser::{CenterPoint, Polarity, PwmPin},
     pins::{self, Channel0VRef, Channel1VRef},
-    steinhart_hart,
 };
 use core::marker::PhantomData;
 use heapless::{consts::U2, Vec};
@@ -558,17 +557,17 @@ impl Channels {
         serde_json_core::to_vec(&summaries)
     }
 
-    fn steinhart_hart_summary(&mut self, channel: usize) -> SteinhartHartSummary {
-        let params = self.channel_state(channel).sh.clone();
-        SteinhartHartSummary { channel, params }
+    fn b_parameter_summary(&mut self, channel: usize) -> BParameterSummary {
+        let params = self.channel_state(channel).bp.clone();
+        BParameterSummary { channel, params }
     }
 
-    pub fn steinhart_hart_summaries_json(
+    pub fn b_parameter_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.steinhart_hart_summary(channel));
+            let _ = summaries.push(self.b_parameter_summary(channel));
         }
         serde_json_core::to_vec(&summaries)
     }
@@ -647,7 +646,7 @@ pub struct PostFilterSummary {
 }
 
 #[derive(Serialize)]
-pub struct SteinhartHartSummary {
+pub struct BParameterSummary {
     channel: usize,
-    params: steinhart_hart::Parameters,
+    params: b_parameter::Parameters,
 }

src/command_handler.rs

@@ -2,7 +2,7 @@ use super::{
     ad7172,
     channels::{Channels, CHANNELS},
     command_parser::{
-        CenterPoint, Command, Ipv4Config, PidParameter, Polarity, PwmPin, ShParameter, ShowCommand,
+        BpParameter, CenterPoint, Command, Ipv4Config, PidParameter, Polarity, PwmPin, ShowCommand,
     },
     config::ChannelConfig,
     dfu,
@@ -113,16 +113,13 @@ impl Handler {
         Ok(Handler::Handled)
     }
 
-    fn show_steinhart_hart(
-        socket: &mut TcpSocket,
-        channels: &mut Channels,
-    ) -> Result<Handler, Error> {
-        match channels.steinhart_hart_summaries_json() {
+    fn show_b_parameter(socket: &mut TcpSocket, channels: &mut Channels) -> Result<Handler, Error> {
+        match channels.b_parameter_summaries_json() {
             Ok(buf) => {
                 send_line(socket, &buf);
             }
             Err(e) => {
-                error!("unable to serialize steinhart-hart summaries: {:?}", e);
+                error!("unable to serialize b parameter summaries: {:?}", e);
                 let _ = writeln!(socket, "{{\"error\":\"{:?}\"}}", e);
                 return Err(Error::Report);
             }
@@ -241,19 +238,19 @@ impl Handler {
         Ok(Handler::Handled)
     }
 
-    fn set_steinhart_hart(
+    fn set_b_parameter(
         socket: &mut TcpSocket,
         channels: &mut Channels,
         channel: usize,
-        parameter: ShParameter,
+        parameter: BpParameter,
         value: f64,
     ) -> Result<Handler, Error> {
-        let sh = &mut channels.channel_state(channel).sh;
-        use super::command_parser::ShParameter::*;
+        let bp = &mut channels.channel_state(channel).bp;
+        use super::command_parser::BpParameter::*;
         match parameter {
-            T0 => sh.t0 = ThermodynamicTemperature::new::<degree_celsius>(value),
-            B => sh.b = TemperatureInterval::new::<kelvin>(value),
-            R0 => sh.r0 = ElectricalResistance::new::<ohm>(value),
+            T0 => bp.t0 = ThermodynamicTemperature::new::<degree_celsius>(value),
+            B => bp.b = TemperatureInterval::new::<kelvin>(value),
+            R0 => bp.r0 = ElectricalResistance::new::<ohm>(value),
         }
         send_line(socket, b"{}");
         Ok(Handler::Handled)
@@ -480,9 +477,7 @@ impl Handler {
             Command::Show(ShowCommand::Input) => Handler::show_report(socket, channels),
             Command::Show(ShowCommand::Pid) => Handler::show_pid(socket, channels),
             Command::Show(ShowCommand::Output) => Handler::show_pwm(socket, channels),
-            Command::Show(ShowCommand::SteinhartHart) => {
-                Handler::show_steinhart_hart(socket, channels)
-            }
+            Command::Show(ShowCommand::BParameter) => Handler::show_b_parameter(socket, channels),
             Command::Show(ShowCommand::PostFilter) => Handler::show_post_filter(socket, channels),
             Command::Show(ShowCommand::Ipv4) => Handler::show_ipv4(socket, ipv4_config),
             Command::OutputPid { channel } => Handler::engage_pid(socket, channels, channel),
@@ -502,11 +497,11 @@ impl Handler {
                 parameter,
                 value,
             } => Handler::set_pid(socket, channels, channel, parameter, value),
-            Command::SteinhartHart {
+            Command::BParameter {
                 channel,
                 parameter,
                 value,
-            } => Handler::set_steinhart_hart(socket, channels, channel, parameter, value),
+            } => Handler::set_b_parameter(socket, channels, channel, parameter, value),
             Command::PostFilter {
                 channel,
                 rate: None,

src/command_parser.rs

@@ -93,7 +93,7 @@ pub enum ShowCommand {
     Input,
     Output,
     Pid,
-    SteinhartHart,
+    BParameter,
     PostFilter,
     Ipv4,
 }
@@ -108,9 +108,9 @@ pub enum PidParameter {
     OutputMax,
 }
 
-/// Steinhart-Hart equation parameter
+/// B-Parameter equation parameter
 #[derive(Debug, Clone, PartialEq)]
-pub enum ShParameter {
+pub enum BpParameter {
     T0,
     B,
     R0,
@@ -172,9 +172,9 @@ pub enum Command {
         parameter: PidParameter,
         value: f64,
     },
-    SteinhartHart {
+    BParameter {
         channel: usize,
-        parameter: ShParameter,
+        parameter: BpParameter,
         value: f64,
     },
     PostFilter {
@@ -366,18 +366,18 @@ fn pid(input: &[u8]) -> IResult<&[u8], Result<Command, Error>> {
     ))(input)
 }
 
-/// `s-h <0-1> <parameter> <value>`
-fn steinhart_hart_parameter(input: &[u8]) -> IResult<&[u8], Result<Command, Error>> {
+/// `b-p <0-1> <parameter> <value>`
+fn b_parameter_parameter(input: &[u8]) -> IResult<&[u8], Result<Command, Error>> {
     let (input, channel) = channel(input)?;
     let (input, _) = whitespace(input)?;
     let (input, parameter) = alt((
-        value(ShParameter::T0, tag("t0")),
-        value(ShParameter::B, tag("b")),
-        value(ShParameter::R0, tag("r0")),
+        value(BpParameter::T0, tag("t0")),
+        value(BpParameter::B, tag("b")),
+        value(BpParameter::R0, tag("r0")),
     ))(input)?;
     let (input, _) = whitespace(input)?;
     let (input, value) = float(input)?;
-    let result = value.map(|value| Command::SteinhartHart {
+    let result = value.map(|value| Command::BParameter {
         channel,
         parameter,
         value,
@@ -385,12 +385,12 @@ fn steinhart_hart_parameter(input: &[u8]) -> IResult<&[u8], Result<Command, Erro
     Ok((input, result))
 }
 
-/// `s-h` | `s-h <steinhart_hart_parameter>`
-fn steinhart_hart(input: &[u8]) -> IResult<&[u8], Result<Command, Error>> {
-    let (input, _) = tag("s-h")(input)?;
+/// `b-p` | `b-p <b_parameter_parameter>`
+fn b_parameter(input: &[u8]) -> IResult<&[u8], Result<Command, Error>> {
+    let (input, _) = tag("b-p")(input)?;
     alt((
-        preceded(whitespace, steinhart_hart_parameter),
-        value(Ok(Command::Show(ShowCommand::SteinhartHart)), end),
+        preceded(whitespace, b_parameter_parameter),
+        value(Ok(Command::Show(ShowCommand::BParameter)), end),
     ))(input)
 }
 
@@ -572,7 +572,7 @@ fn command(input: &[u8]) -> IResult<&[u8], Result<Command, Error>> {
         output,
         center_point,
         pid,
-        steinhart_hart,
+        b_parameter,
         postfilter,
         value(Ok(Command::Dfu), tag("dfu")),
         fan,
@@ -678,7 +678,7 @@ mod test {
 
     #[test]
     fn parse_output_polarity() {
-        let command = Command::parse(b"pwm 0 polarity reversed");
+        let command = Command::parse(b"output 0 polarity reversed");
         assert_eq!(
             command,
             Ok(Command::OutputPolarity {
@@ -753,19 +753,19 @@ mod test {
     }
 
     #[test]
-    fn parse_steinhart_hart() {
-        let command = Command::parse(b"s-h");
-        assert_eq!(command, Ok(Command::Show(ShowCommand::SteinhartHart)));
+    fn parse_b_parameter() {
+        let command = Command::parse(b"b-p");
+        assert_eq!(command, Ok(Command::Show(ShowCommand::BParameter)));
     }
 
     #[test]
-    fn parse_steinhart_hart_set() {
-        let command = Command::parse(b"s-h 1 t0 23.05");
+    fn parse_b_parameter_set() {
+        let command = Command::parse(b"b-p 1 t0 23.05");
         assert_eq!(
             command,
-            Ok(Command::SteinhartHart {
+            Ok(Command::BParameter {
                 channel: 1,
-                parameter: ShParameter::T0,
+                parameter: BpParameter::T0,
                 value: 23.05,
             })
         );

src/config.rs

@@ -1,10 +1,10 @@
 use crate::{
     ad7172::PostFilter,
+    b_parameter,
     channels::Channels,
     command_parser::{CenterPoint, Polarity},
     pid,
     pwm_limits::PwmLimits,
-    steinhart_hart,
 };
 use num_traits::Zero;
 use serde::{Deserialize, Serialize};
@@ -18,7 +18,7 @@ pub struct ChannelConfig {
     pid_engaged: bool,
     i_set: ElectricCurrent,
     polarity: Polarity,
-    sh: steinhart_hart::Parameters,
+    bp: b_parameter::Parameters,
     pwm: PwmLimits,
     /// uses variant `PostFilter::Invalid` instead of `None` to save space
     adc_postfilter: PostFilter,
@@ -47,7 +47,7 @@ impl ChannelConfig {
             pid_engaged: state.pid_engaged,
             i_set,
             polarity: state.polarity.clone(),
-            sh: state.sh.clone(),
+            bp: state.bp.clone(),
             pwm,
             adc_postfilter,
         }
@@ -59,7 +59,7 @@ impl ChannelConfig {
         state.pid.parameters = self.pid.clone();
         state.pid.target = self.pid_target.into();
         state.pid_engaged = self.pid_engaged;
-        state.sh = self.sh.clone();
+        state.bp = self.bp.clone();
 
         self.pwm.apply(channels, channel);
 

src/main.rs

@@ -35,10 +35,10 @@ mod session;
 use session::{Session, SessionInput};
 mod command_parser;
 use command_parser::Ipv4Config;
+mod b_parameter;
 mod channels;
 mod pid;
 mod pwm_limits;
-mod steinhart_hart;
 mod timer;
 use channels::{Channels, CHANNELS};
 mod channel;

src/pwm_limits.rs

@@ -1,8 +1,6 @@
 use crate::channels::Channels;
 use serde::{Deserialize, Serialize};
-use uom::si::{
-    f64::{ElectricCurrent, ElectricPotential},
-};
+use uom::si::f64::{ElectricCurrent, ElectricPotential};
 
 #[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
 pub struct PwmLimits {