implement basic pid controller

.gitignore

@@ -1,2 +1,3 @@
 /kicad/*-backups/
 /kicad/*.lck
+/firmware/cfg.toml

firmware/.cargo/config.toml

@@ -3,7 +3,7 @@ target = "xtensa-esp32s2-espidf"
 
 [target.xtensa-esp32s2-espidf]
 linker = "ldproxy"
-runner = "espflash flash --monitor --before no-reset -a no-reset --no-stub"
+runner = "espflash flash --monitor --before no-reset -a no-reset --no-stub -T part_table.csv"
 rustflags = [ "--cfg",  "espidf_time64"]
 
 [unstable]

firmware/Cargo.toml

@@ -28,6 +28,8 @@ esp-idf-svc = { version = "0.51", features = ["critical-section", "embassy-time-
 anyhow = "1.0.97"
 embedded-graphics       = "0.8.1"
 ssd1306 = "0.9.0"
+toml-cfg = "0.2.0"
 
 [build-dependencies]
 embuild = "0.33"
+toml-cfg = "0.2.0"

firmware/build.rs

@@ -1,3 +1,15 @@
+#[toml_cfg::toml_config]
+pub struct Config {
+    #[default("")]
+    wifi_ssid: &'static str,
+    #[default("")]
+    wifi_psk: &'static str,
+}
+
 fn main() {
+    if !std::path::Path::new("cfg.toml").exists() {
+        panic!("You need to create a `cfg.toml` file with your Wi-Fi credentials! Use `cfg.toml.template` as a template.");
+    }
+
     embuild::espidf::sysenv::output();
 }

firmware/cfg.toml.template

@@ -0,0 +1,3 @@
+[http-server]
+wifi_ssid = "beans32"
+wifi_psk = "12345678"

firmware/part_table.csv

@@ -0,0 +1,5 @@
+# ESP-IDF Partition Table
+# Name,   Type, SubType, Offset,  Size, Flags
+nvs,      data, nvs,     0x9000,  0x6000,
+phy_init, data, phy,     0xf000,  0x1000,
+factory,  app,  factory, 0x10000, 2M,

firmware/src/main.rs

@@ -1,21 +1,61 @@
 mod hid;
+mod wifi;
 
-use std::{thread, time::{Duration, Instant}};
+use std::{sync::{atomic::{AtomicBool, AtomicPtr, Ordering}, Arc, Mutex, RwLock}, thread, time::{Duration, Instant}};
 use anyhow::Result;
 use embedded_graphics::{
     mono_font::{ascii::FONT_6X10, MonoTextStyleBuilder}, 
     pixelcolor::BinaryColor, 
 };
-use esp_idf_svc::hal::{
+use esp_idf_svc::{eventloop::EspSystemEventLoop, hal::{
     adc::{attenuation::DB_11, oneshot::{config::AdcChannelConfig, AdcChannelDriver, AdcDriver}}, 
     gpio::{InterruptType, PinDriver}, 
     i2c::{I2cConfig, I2cDriver}, 
     prelude::Peripherals,
     units::*
-};
+}, http::{server::{Configuration, EspHttpServer}, Method}, io::{EspIOError, Write}};
 use hid::{Button, GPIOIndicatedButton, Indicator};
 use ssd1306::{mode::DisplayConfig, prelude::DisplayRotation, size::DisplaySize128x32, I2CDisplayInterface, Ssd1306};
 
+#[toml_cfg::toml_config]
+pub struct Config {
+    #[default("")]
+    wifi_ssid: &'static str,
+    #[default("")]
+    wifi_psk: &'static str,
+}
+
+struct PIDController {
+    p_gain: f32,
+    i_gain: f32,
+    d_gain: f32,
+    prev_err: f32,
+    sum_err: f32,
+    target: f32,
+}
+
+impl PIDController {
+    pub fn new(p_gain: f32, i_gain: f32, d_gain: f32, target: f32) -> Self {
+        return Self {
+            p_gain,
+            i_gain,
+            d_gain,
+            prev_err: 0_f32,
+            sum_err: 0_f32,
+            target,
+        };
+    }
+
+    pub fn get_control(&mut self, measured: f32) -> f32 {
+        let ctrl_err = self.target - measured;
+        let delta_err = ctrl_err - self.prev_err;
+        let control = self.p_gain * ctrl_err + self.i_gain * self.sum_err + self.d_gain * delta_err;
+        self.sum_err += ctrl_err;
+        self.prev_err = ctrl_err;
+
+        return control;
+    }
+}
 
 fn main() -> Result<()> {
     // It is necessary to call this function once. Otherwise some patches to the runtime
@@ -63,6 +103,22 @@ fn main() -> Result<()> {
 
     log::info!("Hello, world!");
 
+    let sysloop = EspSystemEventLoop::take()?;
+    let app_config = CONFIG;
+
+    // Connect to the Wi-Fi network
+    let _wifi = wifi::wifi(
+        app_config.wifi_ssid,
+        app_config.wifi_psk,
+        peripherals.modem,
+        sysloop,
+    )?;
+    let mut server = EspHttpServer::new(&Configuration::default())?;
+
+    const PID_TARGET: f32 = 70_f32;
+
+    let mut pid = PIDController::new(0.5, 0.01, 0.3, PID_TARGET);
+
     const R1: f32 = 100000_f32;
     const R0: f32 = 100000_f32;
     const V1: f32 = 5_f32;
@@ -70,13 +126,41 @@ fn main() -> Result<()> {
     const B: f32 = 4285_f32;
 
     let mut samples_sum = 0_f32;
-    let mut temperature = 0_f32;
+    let temperature = Arc::new(Mutex::new(0_f32));
+    let c_temperature = Arc::clone(&temperature);
+
+    let pid_control = Arc::new(Mutex::new(0_f32));
+    let c_pid_control = Arc::clone(&pid_control);
+
+    let heater_state = Arc::new(AtomicBool::new(heater_drv_pin.is_set_high()));
+    let c_heater_state = Arc::clone(&heater_state);
+
     let mut i = 0_u32;
 
+    let headers = &[("Content-Type", "text/plain")];
+
+    server.fn_handler(
+        "/metrics",
+        Method::Get,
+        move |request| -> core::result::Result<(), EspIOError> {
+            let mut response = request.into_response(200, Option::None, headers)?;
+            let (pidv, tempv) = {
+                (*pid_control.lock().unwrap(), *temperature.lock().unwrap())
+            };
+            response.write(format!("pid_controller_action {}\n", pidv).as_bytes())?;
+            response.write(format!("pid_controller_target {}\n", PID_TARGET).as_bytes())?;
+            response.write(format!("boiler_temperature {}\n", tempv).as_bytes())?;
+            response.write(format!("boiler_heater_state {}\n", heater_state.load(Ordering::Relaxed) as i32 as f32).as_bytes())?;
+            Ok(())
+        },
+    )?;
+
     let mut blink_time  = Instant::now();
     let mut measure_time  = Instant::now();
     let mut input_time = Option::from(Instant::now());
     
+    let mut is_meltdown_state = false;
+
     loop {
         // when we receive button event, button interrupt will be automatically disabled until we enable it manually
         // so we use this feature to "debounce" our button by enabling interrupt only after some time passes
@@ -88,8 +172,12 @@ fn main() -> Result<()> {
                 heater_drv_pin.set_low()?;
                 btn1.indicator.set_state(false)?;
             } else {
-                heater_drv_pin.set_high()?;
+                if !is_meltdown_state {
-                btn1.indicator.set_state(true)?;
+                    heater_drv_pin.set_high()?;
+                    btn1.indicator.set_state(true)?;
+                } else {
+                    println!("DON'T CLICK WE'RE ABOUT TO EXPLODE!");   
+                }
             }
 
             input_time = Option::from(Instant::now());
@@ -111,8 +199,37 @@ fn main() -> Result<()> {
                 samples_sum += temp;
                 i += 1;
             } else {
-                temperature = samples_sum / 64_f32;
+                let tempv = samples_sum / 64_f32;
-                println!("Temperature value: {}", temperature);
+                let pidv = pid.get_control(tempv);
+                {
+                    let mut t = c_temperature.lock().unwrap();
+                    let mut p = c_pid_control.lock().unwrap();
+                    *t = tempv;
+                    *p = pidv;
+                }
+                
+                println!("Temperature value: {}", tempv);
+                println!("PID Control Value: {}", pidv);
+
+                if !is_meltdown_state {
+                    if pidv > 12_f32 && !heater_drv_pin.is_set_high() {
+                        println!("[PID] Set heater to high");
+                        heater_drv_pin.set_high()?;
+                    } else if pidv < 10_f32  && !heater_drv_pin.is_set_low(){
+                        println!("[PID] Set heater to low");
+                        heater_drv_pin.set_low()?;
+                    }
+                }
+
+                if tempv > 85_f32 {
+                    println!("CRITICAL TEMPERATURE SHUTTING HEATER DOWN");
+                    println!("CRITICAL TEMPERATURE SHUTTING HEATER DOWN");
+                    println!("CRITICAL TEMPERATURE SHUTTING HEATER DOWN");
+                    println!("CRITICAL TEMPERATURE SHUTTING HEATER DOWN");
+                    heater_drv_pin.set_low()?;
+                    is_meltdown_state = true;
+                }
+
                 samples_sum = 0_f32;
                 i = 0;
             }
@@ -142,6 +259,7 @@ fn main() -> Result<()> {
 
             blink_time = Instant::now();
         }
+        c_heater_state.store(heater_drv_pin.is_set_high(), Ordering::Relaxed);
 
         thread::sleep(Duration::from_millis(10));
     }

firmware/src/wifi.rs

@@ -0,0 +1,78 @@
+use anyhow::{bail, Result};
+use esp_idf_svc::{
+    eventloop::EspSystemEventLoop,
+    hal::peripheral,
+    wifi::{AuthMethod, BlockingWifi, ClientConfiguration, Configuration, EspWifi},
+};
+use log::info;
+
+pub fn wifi(
+    ssid: &str,
+    pass: &str,
+    modem: impl peripheral::Peripheral<P = esp_idf_svc::hal::modem::Modem> + 'static,
+    sysloop: EspSystemEventLoop,
+) -> Result<Box<EspWifi<'static>>> {
+    let mut auth_method = AuthMethod::WPA2Personal;
+    if ssid.is_empty() {
+        bail!("Missing WiFi name")
+    }
+    if pass.is_empty() {
+        auth_method = AuthMethod::None;
+        info!("Wifi password is empty");
+    }
+    let mut esp_wifi = EspWifi::new(modem, sysloop.clone(), None)?;
+
+    let mut wifi = BlockingWifi::wrap(&mut esp_wifi, sysloop)?;
+
+    wifi.set_configuration(&Configuration::Client(ClientConfiguration::default()))?;
+
+    info!("Starting wifi...");
+
+    wifi.start()?;
+
+    info!("Scanning...");
+
+    let ap_infos = wifi.scan()?;
+
+    let ours = ap_infos.into_iter().find(|a| a.ssid == ssid);
+
+    let channel = if let Some(ours) = ours {
+        info!(
+            "Found configured access point {} on channel {}",
+            ssid, ours.channel
+        );
+        Some(ours.channel)
+    } else {
+        info!(
+            "Configured access point {} not found during scanning, will go with unknown channel",
+            ssid
+        );
+        None
+    };
+
+    wifi.set_configuration(&Configuration::Client(ClientConfiguration {
+        ssid: ssid
+            .try_into()
+            .expect("Could not parse the given SSID into WiFi config"),
+        password: pass
+            .try_into()
+            .expect("Could not parse the given password into WiFi config"),
+        channel,
+        auth_method,
+        ..Default::default()
+    }))?;
+
+    info!("Connecting wifi...");
+
+    wifi.connect()?;
+
+    info!("Waiting for DHCP lease...");
+
+    wifi.wait_netif_up()?;
+
+    let ip_info = wifi.wifi().sta_netif().get_ip_info()?;
+
+    info!("Wifi DHCP info: {:?}", ip_info);
+
+    Ok(Box::new(esp_wifi))
+}