README.md

@@ -84,7 +84,9 @@ invalidate the first line of input.
 
 ### Reading ADC input
 
-ADC input data is provided in reports. Query for the latest report with the command `report`. See the *Reports* section below.
+Set report mode to `on` for a continuous stream of input data.
+
+The scope of this setting is per TCP session.
 
 
 ### TCP commands
@@ -95,6 +97,8 @@ 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                                           |
@@ -247,7 +251,8 @@ pwm 0 pid
 
 ## Reports
 
-Use the bare `report` command to obtain a single report. Reports are JSON objects
+Use the bare `report` command to obtain a single report. Enable
+continuous reporting with `report mode on`. Reports are JSON objects
 with the following keys.
 
 | Key            | Unit            | Description                                          |

pytec/pytec/client.py

@@ -1,7 +1,6 @@
 import socket
 import json
 import logging
-import time
 
 class CommandError(Exception):
     pass
@@ -127,8 +126,9 @@ 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
@@ -136,7 +136,6 @@ 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

src/channels.rs

@@ -45,11 +45,7 @@ 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,
@@ -386,13 +382,15 @@ impl Channels {
     }
 
     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_TEC_I_DUTY_TO_CURRENT_RATE, MAX_TEC_I)
+        (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_TEC_I_DUTY_TO_CURRENT_RATE, MAX_TEC_I)
+        (duty * max, MAX_TEC_I)
     }
 
     // Get current passing through TEC
@@ -441,16 +439,16 @@ impl Channels {
 
     pub fn set_max_i_pos(&mut self, channel: usize, max_i_pos: ElectricCurrent) -> (ElectricCurrent, ElectricCurrent) {
         let max = ElectricCurrent::new::<ampere>(3.0);
-        let duty = (max_i_pos.min(MAX_TEC_I).max(ElectricCurrent::zero()) / MAX_TEC_I_DUTY_TO_CURRENT_RATE).get::<ratio>();
+        let 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_TEC_I_DUTY_TO_CURRENT_RATE, max)
+        (duty * max, max)
     }
 
     pub fn set_max_i_neg(&mut self, channel: usize, max_i_neg: ElectricCurrent) -> (ElectricCurrent, ElectricCurrent) {
         let max = ElectricCurrent::new::<ampere>(3.0);
-        let duty = (max_i_neg.min(MAX_TEC_I).max(ElectricCurrent::zero()) / MAX_TEC_I_DUTY_TO_CURRENT_RATE).get::<ratio>();
+        let 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_TEC_I_DUTY_TO_CURRENT_RATE, max)
+        (duty * max, max)
     }
 
     fn report(&mut self, channel: usize) -> Report {

src/command_handler.rs

@@ -22,6 +22,7 @@ use super::{
     config::ChannelConfig,
     dfu,
     flash_store::FlashStore,
+    session::Session,
     FanCtrl,
     hw_rev::HWRev,
 };
@@ -86,6 +87,16 @@ 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) => {
@@ -401,9 +412,11 @@ impl Handler {
         }
     }
 
-    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> {
+    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> {
         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),

src/command_parser.rs

@@ -96,6 +96,7 @@ pub struct Ipv4Config {
 #[derive(Debug, Clone, PartialEq)]
 pub enum ShowCommand {
     Input,
+    Reporting,
     Pwm,
     Pid,
     SteinhartHart,
@@ -147,6 +148,7 @@ pub enum Command {
     Reset,
     Ipv4(Ipv4Config),
     Show(ShowCommand),
+    Reporting(bool),
     /// PWM parameter setting
     Pwm {
         channel: usize,
@@ -231,6 +233,12 @@ 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)
 }
@@ -238,8 +246,24 @@ fn channel(input: &[u8]) -> IResult<&[u8], usize> {
 fn report(input: &[u8]) -> IResult<&[u8], Command> {
     preceded(
         tag("report"),
-        // `report` - Report once
-        value(Command::Show(ShowCommand::Input), end)
+        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)
 }
 
@@ -658,6 +682,24 @@ 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");

src/main.rs

@@ -180,7 +180,10 @@ fn main() -> ! {
             loop {
                 let mut new_ipv4_config = None;
                 let instant = Instant::from_millis(i64::from(timer::now()));
-                channels.poll_adc(instant);
+                let updated_channel = channels.poll_adc(instant);
+                if let Some(channel) = updated_channel {
+                    server.for_each(|_, session| session.set_report_pending(channel.into()));
+                }
 
                 fan_ctrl.cycle(channels.current_abs_max_tec_i());
 
@@ -213,7 +216,7 @@ 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, &mut store, &mut ipv4_config, &mut fan_ctrl, hwrev) {
+                                    match Handler::handle_command(command, &mut socket, &mut channels, session, &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(),
@@ -228,6 +231,19 @@ 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

@@ -1,4 +1,5 @@
 use super::command_parser::{Command, Error as ParserError};
+use super::channels::CHANNELS;
 
 const MAX_LINE_LEN: usize = 64;
 
@@ -52,6 +53,8 @@ impl From<Result<Command, ParserError>> for SessionInput {
 
 pub struct Session {
     reader: LineReader,
+    reporting: bool,
+    report_pending: [bool; CHANNELS],
 }
 
 impl Default for Session {
@@ -64,11 +67,43 @@ 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) {
@@ -79,6 +114,12 @@ 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 => {}