Merge branch 'Isak_part1' of ssh://gitea.cs.ru.is:2222/helgie22/ESP_Project4_H26 into Isak_part1

Allt virkar upp að vissu marki.

.gitignore

@@ -3,3 +3,6 @@
 .vscode/c_cpp_properties.json
 .vscode/launch.json
 .vscode/ipch
+scripts
+__pycache__/
+*.typ

README.md

@@ -1,3 +1,3 @@
 # ESP_Project4_H26
 
-A repository for project 3, done in the Embedded System Programming class in Reykjavík University in the Fall semester of 2026
+A repository for project 4, done in the Embedded System Programming class in Reykjavík University in the Fall semester of 2026

docs/diagrams/src/motor_state.wsd

@@ -0,0 +1,50 @@
+@startuml
+' skinparam linetype ortho
+' skinparam nodesep 100
+skinparam ranksep 80
+
+skinparam state {
+    BackgroundColor LightBlue
+}
+
+[*] --> Initialization
+
+state Initialization 
+    Initialization : Entry / Stop motor 
+    Initialization : Entry / Initialize internal parameters
+    Initialization : Entry / Reset speed measurement
+    Initialization : Do / Wait 2 seconds
+    Initialization : Exit / Send Boot-up message
+
+state PreOperational
+    PreOperational : Entry / Stop motor
+    PreOperational : Do / Blink LED at 1 Hz
+    PreOperational : Do / Accept Kp and Ti configuration
+    PreOperational : Do / Select P or PI controller [c]
+    PreOperational : Exit / LED off
+
+state Operational 
+    Operational : Entry / LED on
+    Operational : Do / Run speed controller
+    Operational : Exit / Stop motor and LED off
+
+state Stopped
+    Stopped : Entry / Stop motor
+    Stopped : Do / Blink LED at 2 Hz
+    Stopped : Exit / LED off
+
+Initialization -r-> PreOperational : initialization\n complete
+' Initialization -d-> Operational : initialization\n complete
+
+PreOperational -d-> Operational : set operational [o]
+PreOperational -l--> Initialization : reset [r]
+
+Operational -u-> PreOperational : set pre-operational [p]
+Operational -> Initialization : reset [r]
+Operational --> Stopped : fault detected
+
+Stopped -l-> Initialization : reset [r]
+Stopped -> Operational : set operational [o]
+Stopped -u-> PreOperational : set pre-operational [p]
+
+@enduml

include/digital_in.h

@@ -0,0 +1,31 @@
+#ifndef DIGITAL_IN_H
+#define DIGITAL_IN_H
+
+#include <stdint.h>
+#include <zephyr/drivers/gpio.h>
+
+class Digital_in {
+public:
+    enum : uint8_t {
+        ENCODER_C1 = 0,
+        ENCODER_C2 = 1
+    };
+
+    explicit Digital_in(uint8_t pin_id);
+
+    void init();
+    bool is_hi();
+    bool is_lo();
+
+    // Calls handler on every rising edge of the pin. The caller owns the
+    // gpio_callback struct so it can find its own object with CONTAINER_OF.
+    // Returns 0 on success, or a negative Zephyr error code.
+    int enable_rising_edge_interrupt(
+        struct gpio_callback *callback,
+        gpio_callback_handler_t handler);
+
+private:
+    const struct gpio_dt_spec *gpio;
+};
+
+#endif

include/digital_out.h

@@ -0,0 +1,23 @@
+#ifndef DIGITAL_OUT_H
+#define DIGITAL_OUT_H
+
+#include<stdint.h>
+#include <zephyr/drivers/gpio.h>
+
+struct Digital_out {
+    enum : uint8_t {
+        STATUS_LED = 0
+    };
+
+    explicit Digital_out(uint8_t pin_id);
+
+    void init();
+    void toggle();
+    void set_hi();
+    void set_lo();
+
+private:
+    const struct gpio_dt_spec *gpio;
+};
+
+#endif

include/initialization_state.h

@@ -0,0 +1,27 @@
+#ifndef INITIALIZATION_STATE_H
+#define INITIALIZATION_STATE_H
+
+#include <stdint.h>
+
+#include "state.h"
+
+class InitializationState : public State
+{
+private:
+
+
+    static constexpr int64_t WAIT_MS = 2000;
+    int64_t enter_time_ms = 0;
+
+
+public:
+    void enter() override;
+
+    void update() override;
+
+    void command(char c) override;
+
+    void exit() override;
+};
+
+#endif

include/motor_controller.h

@@ -0,0 +1,97 @@
+#ifndef MOTOR_CONTROLLER_H
+#define MOTOR_CONTROLLER_H
+
+#include <stdint.h>
+
+#include "rotary_encoder_driver.h"
+#include "motor_driver.h"
+#include "p_controller.h"
+#include "digital_out.h"
+
+class State;
+
+
+class MotorController
+{
+private:
+    static constexpr double DEFAULT_REFERENCE_RPM = 25.0;
+    static constexpr double PWM_PER_PERCENT = 255.0 / 100.0;
+    static constexpr uint8_t LED_PIN = Digital_out::STATUS_LED;
+
+    State* current_state;
+
+    State& initialization_state;
+    State& pre_operational_state;
+    State& operational_state;
+    State& stopped_state;
+
+    RotaryEncoderDriver &encoder;
+    MotorDriver &motor;
+    P_controller *controller;
+
+    Digital_out led;
+
+    double reference_rpm;
+
+    // Síðasta sýni, notað fyrir CSV-útprentun
+    double last_actual_rpm;
+    double last_pwm;
+
+
+public:
+    MotorController(
+        RotaryEncoderDriver &encoder,
+        MotorDriver &motor,
+        P_controller &controller,
+        State &initialization,
+        State &pre_operational,
+        State &operational,
+        State &stopped
+    );
+
+
+    void begin();
+
+    void update();
+
+    void command(char c);
+
+    void transition_to(State &new_state);
+
+
+    void to_initialization();
+
+    void to_pre_operational();
+
+    void to_operational();
+
+    void to_stopped();
+
+    bool fault_active();
+
+
+    // Skilar true þegar nýtt sýni var keyrt í gegnum stýringuna
+    bool run_speed_controller();
+
+    double get_reference_rpm() const { return reference_rpm; }
+    double get_actual_rpm() const { return last_actual_rpm; }
+    double get_pwm() const { return last_pwm; }
+
+    void stop_motor();
+
+    void reset_speed_measurement();
+
+    void reset_controller();
+
+    void set_Kp(double value);
+
+    void set_Ti(double value);
+
+    void set_controller(P_controller &new_controller);
+
+    void led_on();
+
+    void led_off();
+};
+
+#endif

include/motor_driver.h

@@ -0,0 +1,25 @@
+#ifndef MOTOR_DRIVER_H
+#define MOTOR_DRIVER_H
+
+class MotorDriver
+{
+public:
+    MotorDriver();
+
+    void begin();
+
+    void forward();
+
+    void reverse();
+
+    void stop();
+
+    void set(double pwm);
+
+    bool fault_active();   // Fault detection for part 2
+
+private:
+    bool initialized; // Flag that ignores motor commands if setup fails
+};
+
+#endif

include/operational_state.h

@@ -0,0 +1,29 @@
+#ifndef OPERATIONAL_STATE_H
+#define OPERATIONAL_STATE_H
+
+#include "state.h"
+#include <stdint.h>
+
+// Sett á 1 til að prenta CSV (time_ms,ref_rpm,actual_rpm,pwm) í Operational,
+// t.d. fyrir step og load response. Einnig hægt með build_flags = -D LOG_CSV=1
+#ifndef LOG_CSV
+#define LOG_CSV 0
+#endif
+
+
+class OperationalState : public State
+{
+private:
+    uint32_t sample_count = 0;
+
+public:
+    void enter() override;
+
+    void update() override;
+
+    void command(char c) override;
+
+    void exit() override;
+};
+
+#endif

include/p_controller.h

@@ -0,0 +1,26 @@
+#ifndef P_CONTROLLER_H
+#define P_CONTROLLER_H
+
+class P_controller
+{
+protected:
+    double Kp;
+
+public:
+    P_controller(double Kp);
+    virtual ~P_controller() {}
+    virtual double update(double ref, double actual);
+    virtual void reset() {}
+
+    virtual void set_Kp(double value)
+    {
+        Kp = value;
+    }
+
+    virtual void set_Ti(double value)
+    {
+        // P controller does not use Ti
+    }
+};
+
+#endif

include/pi_controller.h

@@ -0,0 +1,23 @@
+#ifndef PI_CONTROLLER_H
+#define PI_CONTROLLER_H
+
+#include "p_controller.h"
+
+class PI_controller : public P_controller
+{
+    private:
+        static constexpr double U_MAX = 100.0;  // %
+        static constexpr double U_MIN = -100.0; // %
+
+        double Ti;
+        double T;
+        double integral;
+    public:
+        PI_controller(double Kp, double Ti, double T);
+        double update(double ref, double actual) override;
+        void reset() override;
+
+        void set_Ti(double value) override;
+};
+
+#endif

include/pre_operational_state.h

@@ -0,0 +1,41 @@
+#ifndef PRE_OPERATIONAL_STATE_H
+#define PRE_OPERATIONAL_STATE_H
+
+#include "state.h"
+#include "stdint.h"
+
+class P_controller;
+
+class PreOperationalState : public State
+{
+private:
+    P_controller &p_controller;
+    P_controller &pi_controller;
+    bool pi_selected;
+
+    int64_t previous_time;
+    bool led_state;
+
+
+    enum InputMode
+    {
+        NONE,
+        ENTER_KP,
+        ENTER_TI
+    };
+
+    InputMode input_mode;
+
+    char input_buffer[16];
+    uint8_t input_index;
+
+public:
+    PreOperationalState(P_controller& p_controller, P_controller& pi_controller);
+
+    void enter() override;
+    void update() override;
+    void command(char c) override;
+    void exit() override;
+};
+
+#endif

include/rotary_encoder_driver.h

@@ -0,0 +1,58 @@
+#ifndef ROTARY_ENCODER_DRIVER_H
+#define ROTARY_ENCODER_DRIVER_H
+
+#include <stdint.h>
+#include <zephyr/drivers/gpio.h>
+#include <zephyr/kernel.h>
+
+#include "digital_in.h"
+#include "timer_usec.h"
+
+class RotaryEncoderDriver {
+public:
+    static constexpr uint16_t SAMPLE_PERIOD_US = 4000;   // Ts = 4 ms
+    static constexpr float COUNTS_PER_REV = 1050.0f;
+
+    RotaryEncoderDriver();
+
+    // Returns 0 on success, or a negative Zephyr error code.
+    int begin();
+
+    void update();
+    int32_t position();
+    void update_delta();
+    float count_per_sec();
+    float rpm();
+    bool new_speed_available();
+    void reset_speed_measurement();
+
+    // Blocks until the next speed sample, or until the timeout expires.
+    // Lets the main loop run in step with the 4 ms sampling.
+    void wait_for_sample(k_timeout_t timeout);
+
+private:
+    static const uint8_t HIST_LEN = 4;   // 4 x Ts = 16 ms gluggi fyrir rpm-utreikning
+
+    volatile int32_t count;
+    volatile int16_t delta;
+    volatile bool speed_ready;
+
+    volatile int32_t history[HIST_LEN];
+    volatile uint8_t hist_idx;
+
+    Digital_in eA;
+    Digital_in eB;
+
+    struct gpio_callback encoder_c1_callback;
+    struct k_sem sample_sem;
+    Timer_usec timer;
+
+    static void gpio_edge_handler(
+        const struct device *dev,
+        struct gpio_callback *callback,
+        uint32_t pins);
+
+    static void timer_expired(void *context);
+};
+
+#endif

include/state.h

@@ -0,0 +1,30 @@
+#ifndef STATE_H
+#define STATE_H
+
+class MotorController;
+
+class State
+{
+protected:
+    MotorController* context = nullptr;
+
+public:
+    virtual ~State()
+    {
+    }
+
+    void set_context(MotorController* context)
+    {
+        this->context = context;
+    }
+
+    virtual void enter() = 0;   // LED ON
+
+    virtual void update() = 0;  // run motor controller
+
+    virtual void command(char c) = 0;   // Listen for reset
+
+    virtual void exit() = 0;  // Stop motor
+};
+
+#endif

include/stopped_state.h

@@ -0,0 +1,26 @@
+#ifndef STOPPED_STATE_H
+#define STOPPED_STATE_H
+
+#include <stdint.h>
+
+#include "state.h"
+
+class StoppedState : public State
+{
+private:
+    int64_t previous_time;
+    bool led_state;
+
+public:
+    StoppedState();
+
+    void enter() override;
+
+    void update() override;
+
+    void command(char c) override;
+
+    void exit() override;
+};
+
+#endif

include/timer_usec.h

@@ -0,0 +1,24 @@
+#ifndef TIMER_USEC_H
+#define TIMER_USEC_H
+
+#include <stdint.h>
+#include <zephyr/kernel.h>
+
+class Timer_usec {
+public:
+    using callback_t = void (*)(void *context);
+
+    Timer_usec();
+
+    void set_callback(void (*callback)(void *), void *user_data);
+    void init(uint16_t period_us);
+
+private:
+    struct k_timer timer;
+    callback_t callback;
+    void *callback_context;
+
+    static void expiry_handler(struct k_timer *timer);
+};
+
+#endif

platformio.ini

@@ -13,6 +13,11 @@ platform = ststm32
 board = nucleo_l432kc
 framework = zephyr
 
+monitor_speed = 115200
+
 upload_flags = 
     -c
     reset_config srst_only srst_nogate connect_assert_srst
+
+; CSV-útprentun í Operational fyrir step/load response (sjá capture_serial.py)
+; build_flags = -D LOG_CSV=1

src/app.cpp

@@ -0,0 +1,115 @@
+
+#include <zephyr/device.h>
+#include <zephyr/devicetree.h>
+#include <zephyr/drivers/uart.h>
+#include <zephyr/kernel.h>
+#include <zephyr/sys/printk.h>
+
+#include "rotary_encoder_driver.h"
+#include "motor_driver.h"
+#include "pi_controller.h"
+#include "p_controller.h"
+#include "motor_controller.h"
+
+#include "initialization_state.h"
+
+#include "pre_operational_state.h"
+
+#include "operational_state.h"
+#include "stopped_state.h"
+
+static RotaryEncoderDriver encoder;
+
+static MotorDriver motor;
+
+const double Kp_P = 10.0;     // P-controller from Project 2
+
+const double Kp = 10.125;     // Ziegler-Nichols PI
+const double Ti = 0.0334;
+const double T = 0.004;
+
+static P_controller p_controller(Kp_P);
+static PI_controller pi_controller(Kp, Ti, T);
+
+
+static InitializationState initialization_state;
+// Pre-operational velur á milli stýringanna með 'c'
+static PreOperationalState pre_operational_state(p_controller, pi_controller);
+static OperationalState operational_state;
+static StoppedState stopped_state;
+
+// Stöðurnar verða að vera skilgreindar á undan motor_controller
+static MotorController motor_controller(
+    encoder,
+    motor,
+    pi_controller,      // Sjálfgefin stýring
+    initialization_state,
+    pre_operational_state,
+    operational_state,
+    stopped_state
+);
+
+
+static const struct device *const console_dev =
+    DEVICE_DT_GET(DT_CHOSEN(zephyr_console));
+
+// Received characters are queued by the UART ISR, like the RX buffer that
+// Arduino's Serial had. The USART has a single receive register, so
+// polling it from the main loop loses characters that arrive in a burst.
+K_MSGQ_DEFINE(rx_queue, sizeof(char), 64, 1);
+
+static void uart_rx_isr(const struct device *dev, void *user_data)
+{
+    (void)user_data;
+
+    if (!uart_irq_update(dev)) {
+        return;
+    }
+
+    while (uart_irq_rx_ready(dev)) {
+        unsigned char c;
+
+        if (uart_fifo_read(dev, &c, 1) != 1) {
+            break;
+        }
+
+        // Drop the character if the queue is full.
+        (void)k_msgq_put(&rx_queue, &c, K_NO_WAIT);
+    }
+}
+
+extern "C" void motor_application_main(void)
+{
+    if (!device_is_ready(console_dev)) {
+        printk("Console UART is not ready\n");
+        return;
+    }
+
+    uart_irq_callback_user_data_set(console_dev, uart_rx_isr, nullptr);
+    uart_irq_rx_enable(console_dev);
+
+    const int encoder_result = encoder.begin();
+    if (encoder_result < 0) {
+        printk("Encoder setup failed: %d\n", encoder_result);
+        return;
+    }
+
+    motor.begin();
+    motor_controller.begin();
+
+    while (true) {
+        char received_char;
+
+        // Handle every character the ISR has queued since the last pass.
+        while (k_msgq_get(&rx_queue, &received_char, K_NO_WAIT) == 0) {
+            motor_controller.command(received_char);
+        }
+
+        motor_controller.update();
+
+        // Sleep until the encoder has a new speed sample (every 4 ms), so
+        // the controller runs right after sampling. The timeout only
+        // matters if the timer stops; the thread is idle while it waits.
+        encoder.wait_for_sample(K_MSEC(10));
+    }
+}

src/digital_in.cpp

@@ -0,0 +1,74 @@
+#include "digital_in.h"
+
+#include <errno.h>
+#include <zephyr/devicetree.h>
+#include <zephyr/sys/util.h>
+
+static const struct gpio_dt_spec encoder_c1_gpio =
+    GPIO_DT_SPEC_GET(DT_ALIAS(encoder_c1), gpios);
+
+static const struct gpio_dt_spec encoder_c2_gpio =
+    GPIO_DT_SPEC_GET(DT_ALIAS(encoder_c2), gpios);
+
+Digital_in::Digital_in(uint8_t pin_id)
+    : gpio(nullptr)
+{
+    switch (pin_id) {
+    case ENCODER_C1:
+        gpio = &encoder_c1_gpio;
+        break;
+
+    case ENCODER_C2:
+        gpio = &encoder_c2_gpio;
+        break;
+
+    default:
+        gpio = nullptr;
+        break;
+    }
+}
+
+void Digital_in::init()
+{
+    if (gpio == nullptr || !gpio_is_ready_dt(gpio)) {
+        return;
+    }
+
+    // The overlay supplies the pin's GPIO flags.
+    gpio_pin_configure_dt(gpio, GPIO_INPUT);
+}
+
+bool Digital_in::is_hi()
+{
+    if (gpio == nullptr) {
+        return false;
+    }
+
+    // Read the physical pin level: high is true, low is false.
+    return gpio_pin_get_raw(gpio->port, gpio->pin) > 0;
+}
+
+bool Digital_in::is_lo()
+{
+    return !is_hi();
+}
+
+int Digital_in::enable_rising_edge_interrupt(
+    struct gpio_callback *callback,
+    gpio_callback_handler_t handler)
+{
+    if (gpio == nullptr || !gpio_is_ready_dt(gpio)) {
+        return -ENODEV;
+    }
+
+    gpio_init_callback(callback, handler, BIT(gpio->pin));
+
+    const int ret = gpio_add_callback(gpio->port, callback);
+    if (ret < 0) {
+        return ret;
+    }
+
+    // Physical rising edge, independent of the active level in the overlay.
+    return gpio_pin_interrupt_configure(
+        gpio->port, gpio->pin, GPIO_INT_EDGE_RISING);
+}

src/digital_out.cpp

@@ -0,0 +1,41 @@
+#include "digital_out.h"
+
+#include <zephyr/devicetree.h>
+
+static const struct gpio_dt_spec status_led_gpio =
+    GPIO_DT_SPEC_GET(DT_ALIAS(led0), gpios);
+
+Digital_out::Digital_out(uint8_t pin_id)
+    : gpio(pin_id == STATUS_LED ? &status_led_gpio : nullptr)
+{
+}
+
+void Digital_out::init()
+{
+    if (gpio == nullptr || !gpio_is_ready_dt(gpio)) {
+        return;
+    }
+
+    gpio_pin_configure_dt(gpio, GPIO_OUTPUT_INACTIVE);
+}
+
+void Digital_out::toggle()
+{
+    if (gpio != nullptr) {
+        gpio_pin_toggle_dt(gpio);
+    }
+}
+
+void Digital_out::set_hi()
+{
+    if (gpio != nullptr) {
+        gpio_pin_set_dt(gpio, 1);
+    }
+}
+
+void Digital_out::set_lo()
+{
+    if (gpio != nullptr) {
+        gpio_pin_set_dt(gpio, 0);
+    }
+}

src/initialization_state.cpp

@@ -0,0 +1,37 @@
+#include "initialization_state.h"
+#include "motor_controller.h"
+
+#include <zephyr/kernel.h>
+#include <zephyr/sys/printk.h>
+
+void InitializationState::enter()
+{
+    printk("\nState: Initialization\n");
+
+    context->led_off();
+    context->stop_motor();
+    context->reset_speed_measurement();
+
+    enter_time_ms = k_uptime_get();
+}
+
+
+void InitializationState::update()
+{
+    // Check the time without blocking the application.
+    if ((k_uptime_get() - enter_time_ms) >= WAIT_MS) {
+        context->to_pre_operational();
+    }
+}
+
+
+void InitializationState::command(char c)
+{
+    (void)c;
+}
+
+
+void InitializationState::exit()
+{
+    printk("Boot-up\n");
+}

src/main.c

@@ -1,5 +1,9 @@
 #include <zephyr/kernel.h>
 
-void main(void)
+void motor_application_main(void);
+
+int main(void)
 {
+    motor_application_main();
+    return 0;
 }

src/motor_controller.cpp

@@ -0,0 +1,174 @@
+#include "motor_controller.h"
+#include "state.h"
+
+MotorController::MotorController(
+    RotaryEncoderDriver &encoder,
+    MotorDriver &motor,
+    P_controller &controller,
+    State &initialization,
+    State &pre_operational,
+    State &operational,
+    State &stopped
+)
+    : current_state(nullptr),
+      initialization_state(initialization),
+      pre_operational_state(pre_operational),
+      operational_state(operational),
+      stopped_state(stopped),
+      encoder(encoder),
+      motor(motor),
+      controller(&controller),
+      led(LED_PIN),
+      reference_rpm(DEFAULT_REFERENCE_RPM),
+      last_actual_rpm(0.0),
+      last_pwm(0.0)
+{
+    initialization_state.set_context(this);
+    pre_operational_state.set_context(this);
+    operational_state.set_context(this);
+    stopped_state.set_context(this);
+}
+
+
+void MotorController::begin()
+{
+    led.init();
+    led.set_lo();
+
+    transition_to(initialization_state);
+}
+
+
+void MotorController::transition_to(State &new_state)
+{
+    if (current_state != nullptr) {
+        current_state->exit();
+    }
+
+    current_state = &new_state;
+    current_state->enter();
+}
+
+
+void MotorController::update()
+{
+    if (current_state != nullptr)
+    {
+        current_state->update();
+    }
+}
+
+
+void MotorController::command(char c)
+{
+    if (current_state != nullptr)
+    {
+        current_state->command(c);
+    }
+}
+
+
+void MotorController::to_initialization()
+{
+    transition_to(initialization_state);
+}
+
+void MotorController::to_pre_operational()
+{
+    transition_to(pre_operational_state);
+}
+
+
+void MotorController::to_operational()
+{
+    transition_to(operational_state);
+}
+
+
+bool MotorController::run_speed_controller()
+{
+    if (!encoder.new_speed_available())
+    {
+        return false;
+    }
+
+    const double actual = encoder.rpm();
+
+    const double pwm_percent =
+        controller->update(reference_rpm, actual);
+
+    double pwm =
+        pwm_percent * PWM_PER_PERCENT;
+
+    // Klippt hér svo last_pwm sé nákvæmlega það sem fer á mótorinn
+    if (pwm > 255.0)
+    {
+        pwm = 255.0;
+    }
+    else if (pwm < -255.0)
+    {
+        pwm = -255.0;
+    }
+
+    motor.set(pwm);
+
+    last_actual_rpm = actual;
+    last_pwm = pwm;
+
+    return true;
+}
+
+
+void MotorController::stop_motor()
+{
+    motor.stop();
+}
+
+
+void MotorController::reset_speed_measurement()
+{
+    encoder.reset_speed_measurement();
+}
+
+void MotorController::reset_controller()
+{
+    controller->reset();
+}
+
+void MotorController::set_Kp(double value)
+{
+    controller->set_Kp(value);
+}
+
+void MotorController::set_Ti(double value)
+{
+    controller->set_Ti(value);
+}
+
+void MotorController::set_controller(P_controller& new_controller)
+{
+    controller = &new_controller;
+
+    controller->reset();
+}
+
+void MotorController::to_stopped()
+{
+    transition_to(stopped_state);
+}
+
+bool MotorController::fault_active()
+{
+    return motor.fault_active();
+}
+
+void MotorController::led_on()
+{
+   led.set_hi();
+}
+
+
+void MotorController::led_off()
+{
+   led.set_lo();
+}

src/motor_driver.cpp

@@ -0,0 +1,156 @@
+#include "motor_driver.h"
+
+#include <zephyr/devicetree.h>
+#include <zephyr/drivers/gpio.h>
+#include <zephyr/drivers/pwm.h>
+
+static const struct pwm_dt_spec bin1_pwm =
+    PWM_DT_SPEC_GET(DT_ALIAS(motor_bin1_pwm));
+
+static const struct pwm_dt_spec bin2_pwm =
+    PWM_DT_SPEC_GET(DT_ALIAS(motor_bin2_pwm));
+
+static const struct gpio_dt_spec motor_flt =
+    GPIO_DT_SPEC_GET(DT_ALIAS(motor_flt), gpios);
+
+static const struct gpio_dt_spec fault_test_button = 
+    GPIO_DT_SPEC_GET(DT_ALIAS(fault_test_button), gpios);
+
+static const struct gpio_dt_spec motor_slp =
+    GPIO_DT_SPEC_GET(DT_ALIAS(motor_slp), gpios);
+
+
+MotorDriver::MotorDriver()
+    : initialized(false)
+{
+}
+
+
+void MotorDriver::begin()
+{
+    initialized = false;
+
+    if (!pwm_is_ready_dt(&bin1_pwm) ||
+        !pwm_is_ready_dt(&bin2_pwm) ||
+        !gpio_is_ready_dt(&motor_flt) ||
+        !gpio_is_ready_dt(&fault_test_button) ||
+        !gpio_is_ready_dt(&motor_slp)) {
+        return;
+    }
+
+    if (gpio_pin_configure_dt(&motor_flt, GPIO_INPUT) < 0 ||
+        gpio_pin_configure_dt(&fault_test_button, GPIO_INPUT) < 0 ||
+        gpio_pin_configure_dt(&motor_slp, GPIO_OUTPUT_INACTIVE) < 0) {
+        return;
+    }
+
+    // SLP is active high, so drive it high to enable the DRV8833.
+    if (gpio_pin_set_dt(&motor_slp, 1) < 0) {
+        return;
+    }
+
+    if (pwm_set_dt(&bin1_pwm, bin1_pwm.period, 0) < 0 ||
+        pwm_set_dt(&bin2_pwm, bin2_pwm.period, 0) < 0) {
+        return;
+    }
+    initialized = true;
+    stop();
+}
+
+
+void MotorDriver::forward()
+{
+    set(255.0);
+}
+
+
+void MotorDriver::reverse()
+{
+    set(-255.0);
+}
+
+
+void MotorDriver::stop()
+{
+    if (!initialized) {
+        return;
+    }
+
+    // BIN1 low and BIN2 low puts the DRV8833 in coast mode.
+    pwm_set_dt(&bin1_pwm, bin1_pwm.period, 0);
+    pwm_set_dt(&bin2_pwm, bin2_pwm.period, 0);
+}
+
+void MotorDriver::set(double pwm)
+{
+    if (!initialized) {
+        return;
+    }
+
+    // Limit PWM command
+    if (pwm > 255.0)
+    {
+        pwm = 255.0;
+    } else if (pwm < -255.0) {
+        pwm = -255.0;
+    }
+
+    if (pwm == 0.0) {
+        stop();
+        return;
+    }
+
+
+    const double magnitude = pwm > 0.0 ? pwm : -pwm;
+
+    // Pulse width in nanoseconds, kept as a double until the end so the
+    // 4000-count timer resolution is not lost to integer truncation.
+    const uint32_t pulse = static_cast<uint32_t>(
+        static_cast<double>(bin1_pwm.period) * magnitude / 255.0);
+
+    // Same PWM scheme as Project 3: one input PWM, the other input low,
+    // so both directions use fast decay (coast during the off time).
+    // The idle input is set low first; both channels share TIM1 with
+    // preloaded compare registers, so the change takes effect together
+    // at the next timer update.
+    if (pwm > 0.0) {
+        // Forward: BIN1 PWM, BIN2 low.
+        pwm_set_dt(&bin2_pwm, bin2_pwm.period, 0);
+        pwm_set_dt(&bin1_pwm, bin1_pwm.period, pulse);
+    } else {
+        // Reverse: BIN1 low, BIN2 PWM.
+        pwm_set_dt(&bin1_pwm, bin1_pwm.period, 0);
+        pwm_set_dt(&bin2_pwm, bin2_pwm.period, pulse);
+    }
+}
+
+
+// bool MotorDriver::fault_active()
+// {
+//     //return !(PIND & (1 << PIND4));
+
+//     if (!initialized) {
+//         return true; // Fail safe if the driver did not initialize.
+//     }
+
+//     // The overlay marks FLT as active low. gpio_pin_get_dt() returns
+//     // the logical active state, so 1 means a fault is active.
+//     const int fault = gpio_pin_get_dt(&motor_flt);
+//     return fault < 0 || fault != 0;
+// }
+
+bool MotorDriver::fault_active()
+{
+    if (!initialized) {
+        return true; // Fail safe if the driver did not initialize.
+    }
+
+    // The overlay marks FLT as active low. gpio_pin_get_dt() returns
+    // the logical active state, so 1 means a fault is active.
+    const int driver_fault = gpio_pin_get_dt(&motor_flt);
+    const int button_fault = gpio_pin_get_dt(&fault_test_button);
+    return driver_fault < 0 ||
+           button_fault < 0 ||
+           driver_fault != 0 ||
+           button_fault != 0;
+}

src/operational_state.cpp

@@ -0,0 +1,72 @@
+#include "operational_state.h"
+#include "motor_controller.h"
+
+#include <zephyr/sys/printk.h>
+
+void OperationalState::enter()
+{
+    printk("State: Operational\n");
+
+    context->reset_controller();
+
+    context->led_on();
+
+    sample_count = 0;
+
+#if LOG_CSV
+    printk("time_ms,ref_rpm,actual_rpm,pwm\n");
+#endif
+}
+
+
+void OperationalState::update()
+{
+    if (context->fault_active())
+    {
+        printk("Fault detected\n");
+
+        context->to_stopped();
+
+        return;
+    }
+
+    if (context->run_speed_controller())
+    {
+        ++sample_count;
+
+#if LOG_CSV
+        // 4 ms á milli sýna, tíminn byrjar á 0 við hverja innkomu í Operational
+        printk("%u,%.1f,%.2f,%.1f\n",
+            static_cast<unsigned int>(sample_count * 4U),
+            context->get_reference_rpm(),
+            context->get_actual_rpm(),
+            context->get_pwm());
+#endif
+    }
+}
+
+
+void OperationalState::command(char c)
+{
+    if (c == 'r' || c == 'R')
+    {
+        printk("Command: reset\n");
+
+        context->to_initialization();
+    }
+
+    else if (c == 'p' || c == 'P')
+    {
+         printk("Command: set pre-operational\n");
+
+        context->to_pre_operational();
+    }
+}
+
+
+void OperationalState::exit()
+{
+    context->stop_motor();
+
+    context->led_off();
+}

src/p_controller.cpp

@@ -0,0 +1,13 @@
+#include "p_controller.h"
+
+P_controller::P_controller(double Kp)
+    : Kp(Kp)
+{
+}
+
+double P_controller::update(double ref, double actual)
+{
+    double error = ref - actual;
+
+    return Kp * error;
+}

src/pi_controller.cpp

@@ -0,0 +1,36 @@
+#include "pi_controller.h"
+
+PI_controller::PI_controller(double Kp, double Ti, double T) : P_controller(Kp), Ti(Ti), T(T), integral(0.0)
+{
+}
+
+double PI_controller::update(double ref, double actual)
+{
+    double e = ref - actual;
+    double new_integral = integral + e * T;
+    double u = Kp * (e + new_integral / Ti);
+
+    if (u > U_MAX)
+    {
+        u = U_MAX;
+    }
+    else if (u < U_MIN)
+    {
+        u = U_MIN;
+    }
+    else
+    {
+        integral = new_integral;
+    }
+    return u;
+}
+
+void PI_controller::reset()
+{
+    integral = 0.0;
+}
+
+void PI_controller::set_Ti(double value)
+{
+    Ti = value;
+}

src/pre_operational_state.cpp

@@ -0,0 +1,162 @@
+#include "pre_operational_state.h"
+#include "motor_controller.h"
+
+#include "p_controller.h"
+
+#include <stdlib.h>
+#include <zephyr/kernel.h>
+#include <zephyr/sys/printk.h>
+
+PreOperationalState::PreOperationalState(P_controller &p_controller, P_controller &pi_controller)
+    : p_controller(p_controller),
+      pi_controller(pi_controller),
+      pi_selected(true),
+      previous_time(0),
+      led_state(false),
+      input_mode(NONE),
+      input_index(0)
+{
+}
+
+void PreOperationalState::enter()
+{
+    printk("State: Pre-operational\n");
+
+    // The selection survives a reset, so report it (used by capture_serial.py).
+    printk("Controller: %s\n", pi_selected ? "PI" : "P");
+
+    context->stop_motor();
+
+    context->led_off();
+
+    led_state = false;
+
+    previous_time = k_uptime_get();
+}
+
+void PreOperationalState::update()
+{
+    const int64_t current_time = k_uptime_get();
+
+    if (current_time - previous_time >= 500)
+    {
+        previous_time = current_time;
+
+        led_state = !led_state;
+
+        if (led_state)
+        {
+            context->led_on();
+        }
+        else
+        {
+            context->led_off();
+        }
+    }
+}
+
+void PreOperationalState::command(char c)
+{
+    // We are currently entering a Kp or Ti value
+    if (input_mode != NONE)
+    {
+        // Enter pressed
+        if (c == '\n' || c == '\r')
+        {
+            if (input_index > 0)
+            {
+                // End the string
+                input_buffer[input_index] = '\0';
+
+                // Convert text to a number
+                const double value = atof(input_buffer);
+
+                if (input_mode == ENTER_KP)
+                {
+                    context->set_Kp(value);
+
+                    printk("Kp set to: %.4f\n", value);
+                }
+                else if (input_mode == ENTER_TI)
+                {
+                    context->set_Ti(value);
+
+                    printk("Ti set to: %.4f\n", value);
+                }
+            }
+
+            // Finished entering a value
+            input_index = 0;
+            input_mode = NONE;
+
+            return;
+        }
+
+        // Store number characters
+        if ((c >= '0' && c <= '9') ||
+            c == '.' ||
+            c == '-')
+        {
+            if (input_index < sizeof(input_buffer) - 1)
+            {
+                input_buffer[input_index++] = c;
+            }
+        }
+
+        return;
+    }
+
+
+    // Normal state commands
+    if (c == 'o' || c == 'O')
+    {
+        printk("Command: set operational\n");
+
+        context->to_operational();
+    }
+
+    else if (c == 'r' || c == 'R')
+    {
+         printk("Command: reset\n");
+
+        context->to_initialization();
+    }
+
+    else if (c == 'k' || c == 'K')
+    {
+        input_mode = ENTER_KP;
+        input_index = 0;
+
+        printk("Enter Kp and press Enter:\n");
+    }
+
+    else if (c == 't' || c == 'T')
+    {
+        input_mode = ENTER_TI;
+        input_index = 0;
+
+        printk("Enter Ti and press Enter:\n");
+    }
+
+    // Select controller algorithm, the controller is passed to the motor controller
+    else if (c == 'c' || c == 'C')
+    {
+        pi_selected = !pi_selected;
+
+        if (pi_selected)
+        {
+            context->set_controller(pi_controller);
+            printk("Controller: PI\n");
+        }
+        else
+        {
+            context->set_controller(p_controller);
+            printk("Controller: P\n");
+        }
+    }
+}
+
+void PreOperationalState::exit()
+{
+    context->led_off();
+}

src/rotary_encoder_driver.cpp

@@ -0,0 +1,160 @@
+#include "rotary_encoder_driver.h"
+
+#include <errno.h>
+#include <zephyr/kernel.h>
+#include <zephyr/sys/util.h>
+#include <zephyr/devicetree.h>
+#include <zephyr/drivers/gpio.h>
+
+//#define ISR_PROBE_NODE DT_PATH(zephyr_user)
+
+static const struct gpio_dt_spec isr_probe =
+    GPIO_DT_SPEC_GET(DT_ALIAS(encoder_isr_probe), gpios);
+
+RotaryEncoderDriver::RotaryEncoderDriver()
+    : count(0),
+      delta(0),
+      speed_ready(false),
+      hist_idx(0),
+      eA(Digital_in::ENCODER_C1),
+      eB(Digital_in::ENCODER_C2)
+{
+    for (uint8_t i = 0; i < HIST_LEN; ++i) {
+        history[i] = 0;
+    }
+}
+
+int RotaryEncoderDriver::begin()
+{
+    eA.init();
+    eB.init();
+
+    // Max count 1: the main loop only needs to know that a new sample
+    // exists, not how many it missed.
+    k_sem_init(&sample_sem, 0, 1);
+
+    const int ret = eA.enable_rising_edge_interrupt(
+        &encoder_c1_callback,
+        gpio_edge_handler);
+    if (ret < 0) {
+        return ret;
+    }
+
+    timer.set_callback(timer_expired, this);
+    timer.init(SAMPLE_PERIOD_US);
+    reset_speed_measurement();
+
+    return 0;
+}
+
+void RotaryEncoderDriver::gpio_edge_handler(
+    const struct device *dev,
+    struct gpio_callback *callback,
+    uint32_t pins)
+{
+    // Zephyr only calls this handler for C1, the one pin in the callback.
+    (void)dev;
+    (void)pins;
+
+    auto *encoder = CONTAINER_OF(
+        callback,
+        RotaryEncoderDriver,
+        encoder_c1_callback);
+
+    encoder->update();
+}
+
+void RotaryEncoderDriver::timer_expired(void *context)
+{
+    auto *encoder = static_cast<RotaryEncoderDriver *>(context);
+    encoder->update_delta();
+}
+
+void RotaryEncoderDriver::update()
+{
+    // C2's level at the C1 edge tells us the direction.
+    const bool forward = eB.is_hi();
+
+    const unsigned int key = irq_lock();
+    count += forward ? 1 : -1;
+    irq_unlock(key);
+}
+
+int32_t RotaryEncoderDriver::position()
+{
+    const unsigned int key = irq_lock();
+    const int32_t result = count;
+    irq_unlock(key);
+
+    return result;
+}
+
+void RotaryEncoderDriver::update_delta()
+{
+    const unsigned int key = irq_lock();
+
+    const int32_t current_count = count;
+    const int32_t oldest_count = history[hist_idx];
+
+    history[hist_idx] = current_count;
+    hist_idx = (hist_idx + 1) % HIST_LEN;
+
+    delta = static_cast<int16_t>(current_count - oldest_count);
+    speed_ready = true;
+
+    irq_unlock(key);
+
+    // Wake the main loop so the controller runs right after the sample.
+    k_sem_give(&sample_sem);
+}
+
+void RotaryEncoderDriver::wait_for_sample(k_timeout_t timeout)
+{
+    (void)k_sem_take(&sample_sem, timeout);
+}
+
+float RotaryEncoderDriver::count_per_sec()
+{
+    const unsigned int key = irq_lock();
+    const int16_t local_delta = delta;
+    irq_unlock(key);
+
+    constexpr float window_seconds =
+        HIST_LEN * SAMPLE_PERIOD_US * 1e-6f;
+
+    return local_delta / window_seconds;
+}
+
+float RotaryEncoderDriver::rpm()
+{
+    return count_per_sec() * 60.0f / COUNTS_PER_REV;
+}
+
+bool RotaryEncoderDriver::new_speed_available()
+{
+    const unsigned int key = irq_lock();
+    const bool ready = speed_ready;
+
+    if (ready) {
+        speed_ready = false;
+    }
+
+    irq_unlock(key);
+    return ready;
+}
+
+void RotaryEncoderDriver::reset_speed_measurement()
+{
+    const unsigned int key = irq_lock();
+
+    delta = 0;
+    speed_ready = false;
+
+    for (uint8_t i = 0; i < HIST_LEN; ++i) {
+        history[i] = count;
+    }
+
+    hist_idx = 0;
+
+    irq_unlock(key);
+}

src/stopped_state.cpp

@@ -0,0 +1,81 @@
+#include "stopped_state.h"
+#include "motor_controller.h"
+
+#include <zephyr/kernel.h>
+#include <zephyr/sys/printk.h>
+
+StoppedState::StoppedState()
+    : previous_time(0),
+      led_state(false)
+{
+}
+
+
+void StoppedState::enter()
+{
+    printk("State: Stopped\n");
+
+    context->stop_motor();
+
+    led_state = false;
+
+    context->led_off();
+
+    previous_time = k_uptime_get();
+}
+
+// Controlling the blinking of the LED @ 2Hz
+
+void StoppedState::update()
+{
+    const int64_t current_time = k_uptime_get();
+
+    if (current_time - previous_time >= 250)
+    {
+        previous_time = current_time;
+
+        led_state = !led_state;
+
+        if (led_state)
+        {
+            context->led_on();
+        }
+        else
+        {
+            context->led_off();
+        }
+    }
+}
+
+
+// Commands for Stopped [ r = reset and o for operational]
+
+void StoppedState::command(char c)
+{
+    if (c == 'r' || c == 'R')
+    {
+        printk("Command: reset\n");
+
+        context->to_initialization();
+    }
+
+    else if (c == 'o' || c == 'O')
+    {
+        printk("Command: set operational\n");
+
+        context->to_operational();
+    }
+
+    else if (c == 'p' || c == 'P')
+    {
+        printk("Command: set pre-operational\n");
+
+        context->to_pre_operational();
+    }
+}
+
+
+void StoppedState::exit()
+{
+    context->led_off();
+}

src/timer_usec.cpp

@@ -0,0 +1,39 @@
+#include "timer_usec.h"
+
+Timer_usec::Timer_usec()
+    : callback(nullptr),
+      callback_context(nullptr)
+{
+}
+
+void Timer_usec::set_callback(
+    callback_t callback_function,
+    void *user_data)
+{
+    callback = callback_function;
+    callback_context = user_data;
+}
+
+
+void Timer_usec::init(uint16_t period_us)
+{
+    if (period_us == 0) {
+        return;
+    }
+
+    k_timer_init(&timer, expiry_handler, nullptr);
+    k_timer_user_data_set(&timer, this);
+
+    // The timer fires first after period_us, then repeats every period_us.
+    k_timer_start(&timer, K_USEC(period_us), K_USEC(period_us));
+}
+
+void Timer_usec::expiry_handler(struct k_timer *expired_timer)
+{
+    auto *self =
+        static_cast<Timer_usec *>(k_timer_user_data_get(expired_timer));
+
+    if (self != nullptr && self->callback != nullptr) {
+        self->callback(self->callback_context);
+    }
+}

zephyr/boards/nucleo_l432kc.overlay

@@ -0,0 +1,86 @@
+#include <zephyr/dt-bindings/gpio/gpio.h>
+#include <zephyr/dt-bindings/pwm/pwm.h>
+#include <zephyr/dt-bindings/pwm/stm32_pwm.h>
+
+/ {
+    aliases {
+        encoder-c1 = &encoder_c1;
+        encoder-c2 = &encoder_c2;
+
+        motor-bin1-pwm = &motor_bin1_pwm;
+        motor-bin2-pwm = &motor_bin2_pwm;
+        motor-flt = &motor_flt;
+        motor-slp = &motor_slp;
+        fault-test-button = &fault_test_button;
+    };
+
+    buttons {
+        compatible = "gpio-keys";
+
+        encoder_c1: encoder_c1 {
+            gpios = <&gpiob 7 GPIO_ACTIVE_HIGH>; /* D4, PB7 */
+            label = "Encoder C1";
+        };
+
+        encoder_c2: encoder_c2 {
+            gpios = <&gpiob 6 GPIO_ACTIVE_HIGH>; /* D5, PB6 */
+            label = "Encoder C2";
+        };
+
+        motor_flt: motor_flt {
+            gpios = <&gpioa 0 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>; /* A0, PA0 */
+            label = "Motor fault";
+        };
+        
+        fault_test_button: fault_test_button {
+            gpios = <&gpiob 0 (GPIO_ACTIVE_LOW | GPIO_PULL_UP)>; /* D3, PB0 */
+            label = "Fault test button";
+        };
+    };
+
+    motor_gpio_outputs {
+        compatible = "gpio-leds";
+
+        motor_slp: motor_slp {
+            gpios = <&gpioa 1 GPIO_ACTIVE_HIGH>; /* A1, PA1 */
+            label = "Motor sleep";
+        };
+
+        encoder_isr_probe: encoder_isr_probe {
+            gpios = <&gpioa 12 GPIO_ACTIVE_HIGH>; /* D2, PA12 */
+            label = "Encoder ISR probe";
+        };
+    };
+
+    motor_pwm_outputs {
+        compatible = "pwm-leds";
+
+        motor_bin1_pwm: motor_bin1_pwm {
+            pwms = <&pwm1 1 PWM_USEC(50) 0>; /* D9, PA8; 20 kHz */
+            label = "Motor BIN1 PWM";
+        };
+
+        /* PB1 has no regular TIM1 channel, only the complementary output
+         * TIM1_CH3N. With CH3 itself disabled, CH3N outputs the
+         * non-inverted CH3 reference, so it behaves like a normal channel. */
+        motor_bin2_pwm: motor_bin2_pwm {
+            pwms = <&pwm1 3 PWM_USEC(50) (PWM_POLARITY_NORMAL | STM32_PWM_COMPLEMENTARY)>; /* D6, PB1; 20 kHz */
+            label = "Motor BIN2 PWM";
+        };
+    };
+        zephyr,user {
+        encoder-isr-probe-gpios = <&gpioa 12 GPIO_ACTIVE_HIGH>; /* D2, PA12 */
+    };
+};
+
+&timers1 {
+    status = "okay";
+    /* No prescaler: 80 MHz timer clock, so a 50 us period is 4000 counts. */
+    st,prescaler = <0>;
+
+    pwm1: pwm {
+        status = "okay";
+        pinctrl-0 = <&tim1_ch1_pa8 &tim1_ch3n_pb1>;
+        pinctrl-names = "default";
+    };
+};

zephyr/prj.conf

@@ -0,0 +1,11 @@
+CONFIG_CPP=y
+
+CONFIG_GPIO=y
+CONFIG_PWM=y
+
+CONFIG_SERIAL=y
+CONFIG_CONSOLE=y
+CONFIG_UART_CONSOLE=y
+CONFIG_UART_INTERRUPT_DRIVEN=y
+CONFIG_PRINTK=y
+CONFIG_CBPRINTF_FP_SUPPORT=y