pytec: measure interval

README.md

@@ -89,7 +89,10 @@ Set report mode to `on` for a continuous stream of input data.
 The scope of this setting is per TCP session.
 
 
-### Commands
+### TCP commands
+
+Send commands as simple text string terminated by `\n`. Responses are
+formatted as line-delimited JSON.
 
 | Syntax                           | Function                                                             |
 | ---                              | ---                                                                  |

pytec/example.py

@@ -2,7 +2,10 @@ 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_pid())
+print(tec.get_pwm())
+print(tec.get_postfilter())
 print(tec.get_steinhart_hart())
 for data in tec.report_mode():
     print(data)

pytec/plot.py

@@ -39,21 +39,29 @@ series = {
     'i_tec': Series(),
     'tec_i': Series(),
     'tec_u_meas': Series(),
+    'interval': Series(),
 }
 series_lock = Lock()
 
 quit = False
+last_packet_time = None
 
 def recv_data(tec):
+    global last_packet_time
     for data in tec.report_mode():
         if data['channel'] == 0:
             series_lock.acquire()
             try:
                 time = data['time'] / 1000.0
+                if last_packet_time:
+                    data['interval'] = time - last_packet_time
+                last_packet_time = time
+
                 for k, s in series.items():
-                    v = data[k]
+                    if k in data:
-                    if k in data and type(v) is float:
+                        v = data[k]
-                        s.append(time, v)
+                        if type(v) is float:
+                            s.append(time, v)
             finally:
                 series_lock.release()
 
@@ -108,9 +116,11 @@ def animate(i):
     finally:
         series_lock.release()
 
-    margin_y = 0.01 * (max_y - min_y)
+    if min_x != max_x:
-    ax.set_xlim(min_x, max_x)
+        ax.set_xlim(min_x, max_x)
-    ax.set_ylim(min_y - margin_y, max_y + margin_y)
+    if min_y != max_y:
+        margin_y = 0.01 * (max_y - min_y)
+        ax.set_ylim(min_y - margin_y, max_y + margin_y)
 
     global legend
     legend.remove()

pytec/pytec/client.py

@@ -1,16 +1,14 @@
 import socket
 import json
 
-CHANNELS = 2
+class CommandError(Exception):
+    pass
 
 class Client:
     def __init__(self, host="192.168.1.26", port=23, timeout=None):
         self._socket = socket.create_connection((host, port), timeout)
         self._lines = [""]
 
-    def _command(self, *command):
-        self._socket.sendall((" ".join(command) + "\n").encode('utf-8'))
-        
     def _read_line(self):
         # read more lines
         while len(self._lines) <= 1:
@@ -24,13 +22,19 @@ class Client:
         self._lines = self._lines[1:]
         return line
 
+    def _command(self, *command):
+        self._socket.sendall((" ".join(command) + "\n").encode('utf-8'))
+
+        line = self._read_line()
+        response = json.loads(line)
+        if "error" in response:
+            raise CommandError(response["error"])
+        return response
+
     def _get_conf(self, topic):
-        self._command(topic)
+        result = [None, None]
-        result = []
+        for item in self._command(topic):
-        for channel in range(0, CHANNELS):
+            result[int(item["channel"])] = item
-            line = self._read_line()
-            conf = json.loads(line)
-            result.append(conf)
         return result
 
     def get_pwm(self):

src/channels.rs

@@ -1,3 +1,4 @@
+use heapless::{consts::{U2, U1024}, Vec};
 use serde::{Serialize, Serializer};
 use smoltcp::time::Instant;
 use stm32f4xx_hal::hal;
@@ -412,7 +413,7 @@ impl Channels {
         (duty * max, max)
     }
 
-    pub fn report(&mut self, channel: usize) -> Report {
+    fn report(&mut self, channel: usize) -> Report {
         let vref = self.channel_state(channel).vref;
         let (i_set, _) = self.get_i(channel);
         let i_tec = self.read_itec(channel);
@@ -441,7 +442,23 @@ impl Channels {
         }
     }
 
-    pub fn pwm_summary(&mut self, channel: usize) -> PwmSummary {
+    pub fn reports_json(&mut self) -> Result<JsonBuffer, serde_json_core::ser::Error> {
+        let mut reports = Vec::<_, U2>::new();
+        for channel in 0..CHANNELS {
+            let _ = reports.push(self.report(channel));
+        }
+        serde_json_core::to_vec(&reports)
+    }
+
+    pub fn pid_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.channel_state(channel).pid.summary(channel));
+        }
+        serde_json_core::to_vec(&summaries)
+    }
+
+    fn pwm_summary(&mut self, channel: usize) -> PwmSummary {
         PwmSummary {
             channel,
             center: CenterPointJson(self.channel_state(channel).center.clone()),
@@ -452,19 +469,43 @@ impl Channels {
         }
     }
 
-    pub fn postfilter_summary(&mut self, channel: usize) -> PostFilterSummary {
+    pub fn pwm_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));
+        }
+        serde_json_core::to_vec(&summaries)
+    }
+
+    fn postfilter_summary(&mut self, channel: usize) -> PostFilterSummary {
         let rate = self.adc.get_postfilter(channel as u8).unwrap()
             .and_then(|filter| filter.output_rate());
         PostFilterSummary { channel, rate }
     }
 
-    pub fn steinhart_hart_summary(&mut self, channel: usize) -> SteinhartHartSummary {
+    pub fn postfilter_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.postfilter_summary(channel));
+        }
+        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 }
     }
+
+    pub fn steinhart_hart_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));
+        }
+        serde_json_core::to_vec(&summaries)
+    }
 }
 
-type JsonBuffer = heapless::Vec<u8, heapless::consts::U512>;
+type JsonBuffer = Vec<u8, U1024>;
 
 #[derive(Serialize)]
 pub struct Report {
@@ -484,12 +525,6 @@ pub struct Report {
     pid_output: Option<ElectricCurrent>,
 }
 
-impl Report {
-    pub fn to_json(&self) -> Result<JsonBuffer, serde_json_core::ser::Error> {
-        serde_json_core::to_vec(self)
-    }
-}
-
 pub struct CenterPointJson(CenterPoint);
 
 // used in JSON encoding, not for config
@@ -529,91 +564,14 @@ pub struct PwmSummary {
     max_i_neg: PwmSummaryField<ElectricCurrent>,
 }
 
-impl PwmSummary {
-    pub fn to_json(&self) -> Result<JsonBuffer, serde_json_core::ser::Error> {
-        serde_json_core::to_vec(self)
-    }
-}
-
 #[derive(Serialize)]
 pub struct PostFilterSummary {
     channel: usize,
     rate: Option<f32>,
 }
 
-impl PostFilterSummary {
-    pub fn to_json(&self) -> Result<JsonBuffer, serde_json_core::ser::Error> {
-        serde_json_core::to_vec(self)
-    }
-}
-
 #[derive(Serialize)]
 pub struct SteinhartHartSummary {
     channel: usize,
     params: steinhart_hart::Parameters,
 }
-
-impl SteinhartHartSummary {
-    pub fn to_json(&self) -> Result<JsonBuffer, serde_json_core::ser::Error> {
-        serde_json_core::to_vec(self)
-    }
-}
-
-#[cfg(test)]
-mod test {
-    use super::*;
-
-    #[test]
-    fn report_to_json() {
-        // `/ 1.1` results in values with a really long serialization
-        let report = Report {
-            channel: 0,
-            time: 3200,
-            adc: Some(ElectricPotential::new::<volt>(0.65 / 1.1)),
-            sens: Some(ElectricalResistance::new::<ohm>(10000.0 / 1.1)),
-            temperature: Some(30.0 / 1.1),
-            pid_engaged: false,
-            i_set: ElectricCurrent::new::<ampere>(0.5 / 1.1),
-            vref: ElectricPotential::new::<volt>(1.5 / 1.1),
-            dac_value: ElectricPotential::new::<volt>(2.0 / 1.1),
-            dac_feedback: ElectricPotential::new::<volt>(2.0 / 1.1),
-            i_tec: ElectricPotential::new::<volt>(2.0 / 1.1),
-            tec_i: ElectricCurrent::new::<ampere>(0.2 / 1.1),
-            tec_u_meas: ElectricPotential::new::<volt>(2.0 / 1.1),
-            pid_output: Some(ElectricCurrent::new::<ampere>(0.5 / 1.1)),
-        };
-        let buf = report.to_json().unwrap();
-        assert_eq!(buf[0], b'{');
-        assert_eq!(buf[buf.len() - 1], b'}');
-    }
-
-    #[test]
-    fn pwm_summary_to_json() {
-        let value = 1.0 / 1.1;
-        let max = 5.0 / 1.1;
-
-        let pwm_summary = PwmSummary {
-            channel: 0,
-            center: CenterPointJson(CenterPoint::Vref),
-            i_set: PwmSummaryField {
-                value: ElectricCurrent::new::<ampere>(value),
-                max: ElectricCurrent::new::<ampere>(max),
-            },
-            max_v: PwmSummaryField {
-                value: ElectricPotential::new::<volt>(value),
-                max: ElectricPotential::new::<volt>(max),
-            },
-            max_i_pos: PwmSummaryField {
-                value: ElectricCurrent::new::<ampere>(value),
-                max: ElectricCurrent::new::<ampere>(max),
-            },
-            max_i_neg: PwmSummaryField {
-                value: ElectricCurrent::new::<ampere>(value),
-                max: ElectricCurrent::new::<ampere>(max),
-            },
-        };
-        let buf = pwm_summary.to_json().unwrap();
-        assert_eq!(buf[0], b'{');
-        assert_eq!(buf[buf.len() - 1], b'}');
-    }
-}

src/main.rs

@@ -81,7 +81,8 @@ const TCP_PORT: u16 = 23;
 fn send_line(socket: &mut TcpSocket, data: &[u8]) -> bool {
     let send_free = socket.send_capacity() - socket.send_queue();
     if data.len() > send_free + 1 {
-        // Not enough buffer space, skip report for now
+        // Not enough buffer space, skip report for now,
+        // instead of sending incomplete line
         warn!(
             "TCP socket has only {}/{} needed {}",
             send_free + 1, socket.send_capacity(), data.len(),
@@ -103,17 +104,6 @@ fn send_line(socket: &mut TcpSocket, data: &[u8]) -> bool {
     false
 }
 
-fn report_to(channel: usize, channels: &mut Channels, socket: &mut TcpSocket) -> bool {
-    match channels.report(channel).to_json() {
-        Ok(buf) =>
-            send_line(socket, &buf[..]),
-        Err(e) => {
-            error!("unable to serialize report: {:?}", e);
-            false
-        }
-    }
-}
-
 /// Initialization and main loop
 #[cfg(not(test))]
 #[entry]
@@ -221,68 +211,79 @@ fn main() -> ! {
                         socket.close()
                     } else if socket.can_send() && socket.can_recv() {
                         match socket.recv(|buf| session.feed(buf)) {
-                            Ok(SessionInput::Nothing) => {}
+                            Ok(SessionInput::Nothing) => {
+                                send_line(&mut socket, b"{}");
+                            }
                             Ok(SessionInput::Command(command)) => match command {
                                 Command::Quit =>
                                     socket.close(),
                                 Command::Reporting(_reporting) => {
                                     // handled by session
+                                    send_line(&mut socket, b"{}");
                                 }
                                 Command::Show(ShowCommand::Reporting) => {
                                     let _ = writeln!(socket, "{{ \"report\": {:?} }}", session.reporting());
                                 }
                                 Command::Show(ShowCommand::Input) => {
-                                    for channel in 0..CHANNELS {
+                                    match channels.reports_json() {
-                                        report_to(channel, &mut channels, &mut socket);
+                                        Ok(buf) => {
+                                            send_line(&mut socket, &buf[..]);
+                                        }
+                                        Err(e) => {
+                                            error!("unable to serialize report: {:?}", e);
+                                            let _ = writeln!(socket, "{{\"error\":\"{:?}\"}}", e);
+
+                                        }
                                     }
                                 }
                                 Command::Show(ShowCommand::Pid) => {
-                                    for channel in 0..CHANNELS {
+                                    match channels.pid_summaries_json() {
-                                        match channels.channel_state(channel).pid.summary(channel).to_json() {
+                                        Ok(buf) => {
-                                            Ok(buf) => {
+                                            send_line(&mut socket, &buf);
-                                                send_line(&mut socket, &buf);
+                                        }
-                                            }
+                                        Err(e) => {
-                                            Err(e) =>
+                                            error!("unable to serialize pid summary: {:?}", e);
-                                                error!("unable to serialize pid summary: {:?}", e),
+                                            let _ = writeln!(socket, "{{\"error\":\"{:?}\"}}", e);
                                         }
                                     }
                                 }
                                 Command::Show(ShowCommand::Pwm) => {
-                                    for channel in 0..CHANNELS {
+                                    match channels.pwm_summaries_json() {
-                                        match channels.pwm_summary(channel).to_json() {
+                                        Ok(buf) => {
-                                            Ok(buf) => {
+                                            send_line(&mut socket, &buf);
-                                                send_line(&mut socket, &buf);
+                                        }
-                                            }
+                                        Err(e) => {
-                                            Err(e) =>
+                                            error!("unable to serialize pwm summary: {:?}", e);
-                                                error!("unable to serialize pwm summary: {:?}", e),
+                                            let _ = writeln!(socket, "{{\"error\":\"{:?}\"}}", e);
                                         }
                                     }
                                 }
                                 Command::Show(ShowCommand::SteinhartHart) => {
-                                    for channel in 0..CHANNELS {
+                                    match channels.steinhart_hart_summaries_json() {
-                                        match channels.steinhart_hart_summary(channel).to_json() {
+                                        Ok(buf) => {
-                                            Ok(buf) => {
+                                            send_line(&mut socket, &buf);
-                                                send_line(&mut socket, &buf);
+                                        }
-                                            }
+                                        Err(e) => {
-                                            Err(e) =>
+                                            error!("unable to serialize steinhart-hart summaries: {:?}", e);
-                                                error!("unable to serialize steinhart-hart summary: {:?}", e),
+                                            let _ = writeln!(socket, "{{\"error\":\"{:?}\"}}", e);
                                         }
                                     }
                                 }
                                 Command::Show(ShowCommand::PostFilter) => {
-                                    for channel in 0..CHANNELS {
+                                    match channels.postfilter_summaries_json() {
-                                        match channels.postfilter_summary(channel).to_json() {
+                                        Ok(buf) => {
-                                            Ok(buf) => {
+                                            send_line(&mut socket, &buf);
-                                                send_line(&mut socket, &buf);
+                                        }
-                                            }
+                                        Err(e) => {
-                                            Err(e) =>
+                                            error!("unable to serialize postfilter summary: {:?}", e);
-                                                error!("unable to serialize postfilter summary: {:?}", e),
+                                            let _ = writeln!(socket, "{{\"error\":\"{:?}\"}}", e);
                                         }
                                     }
                                 }
                                 Command::PwmPid { channel } => {
                                     channels.channel_state(channel).pid_engaged = true;
                                     leds.g3.on();
+                                    send_line(&mut socket, b"{}");
                                 }
                                 Command::Pwm { channel, pin, value } => {
                                     match pin {
@@ -306,6 +307,7 @@ fn main() -> ! {
                                             channels.set_max_i_neg(channel, current);
                                         }
                                     }
+                                    send_line(&mut socket, b"{}");
                                 }
                                 Command::CenterPoint { channel, center } => {
                                     let (i_tec, _) = channels.get_i(channel);
@@ -314,6 +316,7 @@ fn main() -> ! {
                                     if !state.pid_engaged {
                                         channels.set_i(channel, i_tec);
                                     }
+                                    send_line(&mut socket, b"{}");
                                 }
                                 Command::Pid { channel, parameter, value } => {
                                     let pid = &mut channels.channel_state(channel).pid;
@@ -336,6 +339,7 @@ fn main() -> ! {
                                         IntegralMax =>
                                             pid.parameters.integral_max = value as f32,
                                     }
+                                    send_line(&mut socket, b"{}");
                                 }
                                 Command::SteinhartHart { channel, parameter, value } => {
                                     let sh = &mut channels.channel_state(channel).sh;
@@ -345,29 +349,41 @@ fn main() -> ! {
                                         B => sh.b = value,
                                         R0 => sh.r0 = ElectricalResistance::new::<ohm>(value),
                                     }
+                                    send_line(&mut socket, b"{}");
                                 }
                                 Command::PostFilter { channel, rate: None } => {
                                     channels.adc.set_postfilter(channel as u8, None).unwrap();
+                                    send_line(&mut socket, b"{}");
                                 }
                                 Command::PostFilter { channel, rate: Some(rate) } => {
                                     let filter = ad7172::PostFilter::closest(rate);
                                     match filter {
-                                        Some(filter) =>
+                                        Some(filter) => {
-                                            channels.adc.set_postfilter(channel as u8, Some(filter)).unwrap(),
+                                            channels.adc.set_postfilter(channel as u8, Some(filter)).unwrap();
-                                        None =>
+                                            send_line(&mut socket, b"{}");
-                                            error!("unable to choose postfilter for rate {:.3}", rate),
+                                        }
+                                        None => {
+                                            error!("unable to choose postfilter for rate {:.3}", rate);
+                                            send_line(&mut socket, b"{{\"error\": \"unable to choose postfilter rate\"}}");
+                                        }
                                     }
                                 }
                                 Command::Load { channel } => {
                                     for c in 0..CHANNELS {
                                         if channel.is_none() || channel == Some(c) {
                                             match store.read_value::<ChannelConfig>(CHANNEL_CONFIG_KEY[c]) {
-                                                Ok(Some(config)) =>
+                                                Ok(Some(config)) => {
-                                                    config.apply(&mut channels, c),
+                                                    config.apply(&mut channels, c);
-                                                Ok(None) =>
+                                                    send_line(&mut socket, b"{}");
-                                                    error!("flash config not found"),
+                                                }
-                                                Err(e) =>
+                                                Ok(None) => {
-                                                    error!("unable to load config from flash: {:?}", e),
+                                                    error!("flash config not found");
+                                                    send_line(&mut socket, b"{{\"error\": \"flash config not found\"}}");
+                                                }
+                                                Err(e) => {
+                                                    error!("unable to load config from flash: {:?}", e);
+                                                    let _ = writeln!(socket, "{{\"error\":\"{:?}\"}}", e);
+                                                }
                                             }
                                         }
                                     }
@@ -376,9 +392,13 @@ fn main() -> ! {
                                     for c in 0..CHANNELS {
                                         if channel.is_none() || channel == Some(c) {
                                             let config = ChannelConfig::new(&mut channels, c);
-                                            let _ = store
+                                            match store.write_value(CHANNEL_CONFIG_KEY[c], &config, &mut store_value_buf) {
-                                                .write_value(CHANNEL_CONFIG_KEY[c], &config, &mut store_value_buf)
+                                                Ok(()) => {}
-                                                .map_err(|e| error!("unable to save channel {} config to flash: {:?}", c, e));
+                                                Err(e) => {
+                                                    error!("unable to save channel {} config to flash: {:?}", c, e);
+                                                    let _ = writeln!(socket, "{{\"error\":\"{:?}\"}}", e);
+                                                }
+                                            }
                                         }
                                     }
                                 }
@@ -387,6 +407,7 @@ fn main() -> ! {
                                         .write_value("ipv4", &config, [0; 16])
                                         .map_err(|e| error!("unable to save ipv4 config to flash: {:?}", e));
                                     new_ipv4_config = Some(config);
+                                    send_line(&mut socket, b"{}");
                                 }
                                 Command::Reset => {
                                     for i in 0..CHANNELS {
@@ -405,8 +426,15 @@ fn main() -> ! {
                         }
                     } else if socket.can_send() {
                         if let Some(channel) = session.is_report_pending() {
-                            if report_to(channel, &mut channels, &mut socket) {
+                            match channels.reports_json() {
-                                session.mark_report_sent(channel);
+                                Ok(buf) => {
+                                    send_line(&mut socket, &buf[..]);
+                                    session.mark_report_sent(channel);
+                                }
+                                Err(e) => {
+                                    error!("unable to serialize report: {:?}", e);
+
+                                }
                             }
                         }
                     }

src/pid.rs

@@ -91,8 +91,6 @@ impl Controller {
     }
 }
 
-type JsonBuffer = heapless::Vec<u8, heapless::consts::U360>;
-
 #[derive(Clone, Serialize, Deserialize)]
 pub struct Summary {
     channel: usize,
@@ -101,12 +99,6 @@ pub struct Summary {
     integral: f64,
 }
 
-impl Summary {
-    pub fn to_json(&self) -> Result<JsonBuffer, serde_json_core::ser::Error> {
-        serde_json_core::to_vec(self)
-    }
-}
-
 #[cfg(test)]
 mod test {
     use super::*;