fsm_thermostat.c

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/* Includes ------------------------------------------------------------------*/
/* Standard C includes */
#include <stdlib.h>
#include <string.h>
 
/* Project includes */
#include "fsm_thermostat.h"
#include "port_thermostat.h"
#include "port_led.h"
#include "port_temp_sensor.h"
 
/* State machine input or transition functions */
 
bool check_heat(fsm_t *p_this)
{
    // Retrieve the FSM structure and get the temperature sensor
    fsm_thermostat_t *p_fsm = (fsm_thermostat_t *)p_this;
 
    // Get the temperature from the sensor
    if (port_temp_sensor_get_temperature(p_fsm->p_temp_sensor) < p_fsm->threshold_temp_celsius)
    {
        return true;
    }
    else
    {
        return false;
    }
}
 
bool check_comfort(fsm_t *p_this)
{
    return !check_heat(p_this);
}
 
/* State machine output or action functions */
 
void do_thermostat_on(fsm_t *p_this)
{
    // Retrieve the FSM structure and get the LED
    fsm_thermostat_t *p_fsm = (fsm_thermostat_t *)p_this;
 
    // Set the LEDs according to the thermostat status
    port_led_on(p_fsm->p_led_heat);
    port_led_off(p_fsm->p_led_comfort);
 
    // Store the event
    p_fsm->last_events[p_fsm->event_idx] = ACTIVATION;
    p_fsm->last_time_events[p_fsm->event_idx] = port_system_get_millis();
    p_fsm->event_idx = (p_fsm->event_idx + 1) % THERMOSTAT_HISTORY;
}
 
void do_thermostat_off(fsm_t *p_this)
{
    // Retrieve the FSM structure and get the LED
    fsm_thermostat_t *p_fsm = (fsm_thermostat_t *)p_this;
 
    // Set the LEDs according to the thermostat status
    port_led_off(p_fsm->p_led_heat);
    port_led_on(p_fsm->p_led_comfort);
 
    // Store the event
    p_fsm->last_events[p_fsm->event_idx] = DEACTIVATION;
    p_fsm->last_time_events[p_fsm->event_idx] = port_system_get_millis();
    p_fsm->event_idx = (p_fsm->event_idx + 1) % THERMOSTAT_HISTORY;
}
 
/* Transitions table ---------------------------------------------------------*/
fsm_trans_t fsm_trans_thermostat[] = {
    {THERMOSTAT_OFF, check_heat, THERMOSTAT_ON, do_thermostat_on},
    {THERMOSTAT_ON, check_comfort, THERMOSTAT_OFF, do_thermostat_off},
    {-1, NULL, -1, NULL},
};
 
uint32_t fsm_thermostat_get_last_time_event(fsm_t *p_this, uint8_t event)
{
    fsm_thermostat_t *p_fsm = (fsm_thermostat_t *)p_this;
 
    // Look for the last time the event was detected, if it was detected. If not, return 0
    for (int i = 0; i < THERMOSTAT_HISTORY; i++)
    {
        if (p_fsm->last_events[i] == event)
        {
            return p_fsm->last_time_events[i];
        }
    }
    return 0;
}
 
uint8_t fsm_thermostat_get_status(fsm_t *p_this)
{
    fsm_thermostat_t *p_fsm = (fsm_thermostat_t *)p_this;
    return p_fsm->last_events[p_fsm->event_idx];
}
 
/* Initialize the FSM */
 
void fsm_thermostat_init(fsm_t *p_this, port_led_hw_t *p_led_heat, port_led_hw_t *p_led_comfort, port_temp_hw_t *p_temp)
{
    fsm_thermostat_t *p_fsm = (fsm_thermostat_t *)(p_this);
    fsm_init(p_this, fsm_trans_thermostat);
 
    // Assign the peripherals to the FSM
    p_fsm->p_led_heat = p_led_heat;
    p_fsm->p_led_comfort = p_led_comfort;
    p_fsm->p_temp_sensor = p_temp;
 
    // Initialize the last time the thermostat was activated
    memset(p_fsm->last_time_events, 0, sizeof(p_fsm->last_time_events));
 
    // Initialize the thermostat status
    memset(p_fsm->last_events, UNKNOWN, sizeof(p_fsm->last_events));
 
    // Initialize the event index
    p_fsm->event_idx = 0;
 
    // Initialize the threshold temperature
    p_fsm->threshold_temp_celsius = THERMOSTAT_DEFAULT_THRESHOLD;
 
    // Initialize the timer to measure the temperature
    p_fsm->timer_period_sec = THERMOSTAT_TIMEOUT_SEC;
 
    // Initialize the timer
    port_thermostat_timer_setup(p_fsm);
 
    // Initialize the peripherals
    port_led_init(p_led_heat);
    port_led_init(p_led_comfort);    
    port_temp_sensor_init(p_temp);
}
 
/* Create FSM */
fsm_t *fsm_thermostat_new(port_led_hw_t *p_led_heat, port_led_hw_t *p_led_comfort, port_temp_hw_t *p_temp)
{
    // Do malloc for the whole FSM structure to reserve memory for the rest of the FSM, although I interpret it as fsm_t which is the first field of the structure so that the FSM library can work with it
    fsm_t *p_fsm = malloc(sizeof(fsm_thermostat_t));
 
    // Initialize the FSM
    fsm_thermostat_init(p_fsm, p_led_heat, p_led_comfort, p_temp);
 
    return p_fsm;
}