coffee/barista/barista.ino
2025-10-13 21:09:06 +02:00

350 lines
6.7 KiB
C++

/* Copyright (c) 2025 Rodrigo Arias Mallo <rodarima@gmail.com>
* SPDX-License-Identifier: GPL-3.0-or-later */
#include "ntc.h"
#include "pinout.h"
enum logic {
ON = 1,
OFF = 0,
};
#define DEBOUNCE_TIME 20L /* ms */
#define TEMP_MIN 80.0f
#define TEMP_MAX 90.0f
#define LED_MIN_VALUE 0
enum machine_state {
SLEEPING = 0,
DEBOUNCE,
HEATING,
HOT,
BREWING,
COOLING,
};
//int state = SLEEPING;
enum btn_index {
BTN_ON = 0,
BTN_HOT,
MAX_BTN,
};
enum btn_state {
RESTING = 0,
PRESSING,
PRESSED,
RELEASING,
RELEASED,
};
enum buzz_state {
BUZZ_OFF = 0,
BUZZ_HEY,
BUZZ_ACTIVE,
};
int button_pin[MAX_BTN] = {
[BTN_ON] = PIN_POWER_ON,
[BTN_HOT] = PIN_HOT,
};
struct btn {
enum btn_state state;
unsigned long press_t0;
unsigned long release_t0;
};
struct input {
int ntc_V;
enum logic btn[MAX_BTN];
} g_in;
#define MAX_SAMPLES 16
struct state {
enum machine_state mstate;
unsigned long brewing_t0;
unsigned long cooling_t0;
unsigned long heating_t0;
unsigned long hot_t0;
int ntc_i; /* Next available place */
float ntc_R;
float ntc_last_T;
float ntc_array_T[MAX_SAMPLES];
float ntc_T; /* average */
struct btn btn[MAX_BTN];
enum buzz_state buzz_state;
unsigned long buzz_t0;
} g_st;
int read_input(int pin)
{
return !digitalRead(pin);
}
void relay(int pin, enum logic st)
{
/* Relays are active low */
if (st == ON)
digitalWrite(pin, 0);
else
digitalWrite(pin, 1);
}
void setled(int pin, enum logic st)
{
/* LEDs are active high */
if (st == ON)
digitalWrite(pin, 1);
else
digitalWrite(pin, 0);
}
void do_input(struct input *input)
{
/* Read buttons */
for (int i = 0; i < MAX_BTN; i++)
input->btn[i] = read_input(button_pin[i]);
/* Read temperature sensor */
input->ntc_V = analogRead(PIN_NTC);
}
void proc_ntc(struct state *state, const struct input *input)
{
state->ntc_R = ntc_resistance(input->ntc_V);
state->ntc_last_T = ntc_temp(state->ntc_R);
state->ntc_array_T[state->ntc_i++] = state->ntc_last_T;
if (state->ntc_i >= MAX_SAMPLES)
state->ntc_i = 0;
float avg = 0;
for (int i = 0; i < MAX_SAMPLES; i++)
avg += state->ntc_array_T[i];
state->ntc_T = avg / MAX_SAMPLES;
}
void proc_buttons(struct state *state, const struct input *input)
{
for (int i = 0; i < MAX_BTN; i++) {
struct btn *btn = &state->btn[i];
int v = input->btn[i];
if (btn->state == RESTING) {
if (v == ON) {
btn->state = PRESSING;
btn->press_t0 = millis();
}
} else if (btn->state == PRESSING) {
if (v != ON) {
btn->state = RESTING;
} else if (millis() - btn->press_t0 > DEBOUNCE_TIME) {
btn->state = PRESSED;
}
} else if (btn->state == PRESSED) {
if (v != ON) {
btn->state = RELEASING;
btn->release_t0 = millis();
}
} else if (btn->state == RELEASING) {
if (v == ON) {
btn->state = PRESSED;
} else if (millis() - btn->release_t0 > DEBOUNCE_TIME) {
btn->state = RELEASED;
}
} else if (btn->state == RELEASED) {
btn->state = RESTING;
}
}
}
int red_min = 50;
int red_state = red_min;
unsigned long brewing_time = 3000UL; /* 3 seconds */
unsigned long cooling_time = 3000UL; /* 3 seconds */
unsigned long max_heating_time = 10000UL; /* 10 seconds */
unsigned long max_idle_time = 10000UL; /* 10 seconds */
void proc_machine(struct state *st)
{
float temp = st->ntc_T;
int on = (st->btn[BTN_ON].state == RELEASED);
int hot = (st->btn[BTN_HOT].state == PRESSED);
Serial.print("state=");
Serial.print(st->mstate);
Serial.print(" on=");
Serial.print(on);
Serial.print(" temp=");
Serial.print(temp);
Serial.println(" C");
/* Pressing ON cancels any operation */
if (st->mstate != SLEEPING && on) {
st->mstate = SLEEPING;
st->buzz_state = BUZZ_OFF;
return;
}
if (st->mstate == SLEEPING) {
if (on) {
st->mstate = HEATING;
st->heating_t0 = millis();
Serial.println("heating");
}
} else if (st->mstate == HEATING) {
if (temp > TEMP_MAX) {
st->mstate = HOT;
st->hot_t0 = millis();
st->buzz_state = BUZZ_HEY;
Serial.println("hot");
} else if (millis() - st->heating_t0 > max_heating_time) {
/* TODO: Add alarm state */
st->mstate = SLEEPING;
Serial.println("cannot heat, going to sleep");
}
} else if (st->mstate == HOT) {
if (hot) {
st->mstate = BREWING;
st->brewing_t0 = millis();
Serial.println("brewing");
} else if (millis() - st->hot_t0 > max_idle_time) {
st->mstate = SLEEPING;
Serial.println("idle timeout, going to sleep");
}
} else if (st->mstate == BREWING) {
if (millis() - st->brewing_t0 > brewing_time) {
st->mstate = COOLING;
st->cooling_t0 = millis();
Serial.println("cooling");
}
} else if (st->mstate == COOLING) {
/* TODO: Wait a bit and go back to heating */
if (millis() - st->cooling_t0 > cooling_time) {
st->mstate = HEATING;
st->heating_t0 = millis();
Serial.println("heating");
}
}
}
void
proc_buzz(struct state *st)
{
if (st->buzz_state == BUZZ_HEY) {
tone(PIN_BUZZ, 1500);
st->buzz_state = BUZZ_ACTIVE;
st->buzz_t0 = millis();
} else if (st->buzz_state == BUZZ_ACTIVE) {
if (millis() - st->buzz_t0 > 20) {
st->buzz_state = BUZZ_OFF;
noTone(PIN_BUZZ);
}
} else {
noTone(PIN_BUZZ);
}
}
void do_proc(struct state *st, const struct input *input)
{
proc_ntc(st, input);
proc_buttons(st, input);
proc_machine(st);
proc_buzz(st);
}
void
output_leds(const struct state *st)
{
static int r = 0;
static int g = 0;
if (st->mstate == HEATING || st->mstate == COOLING) {
analogWrite(PIN_LED_RED, r);
setled(PIN_LED_GREEN, 0);
if (r >= 255)
r = 0;
else
r += 3;
} else if (st->mstate == HOT) {
setled(PIN_LED_RED, 0);
setled(PIN_LED_GREEN, 1);
r = 0;
} else if (st->mstate == BREWING) {
setled(PIN_LED_RED, 0);
analogWrite(PIN_LED_GREEN, g);
if (g >= 255)
g = 0;
else
g += 3;
} else {
setled(PIN_LED_RED, 0);
setled(PIN_LED_GREEN, 0);
r = 0;
}
}
void
output_heater(const struct state *st)
{
if (st->mstate == HEATING || st->mstate == HOT || st->mstate == BREWING) {
if (st->ntc_T < TEMP_MIN)
relay(PIN_HEAT, ON);
else if (st->ntc_T > TEMP_MAX)
relay(PIN_HEAT, OFF);
} else {
relay(PIN_HEAT, OFF);
}
}
void
output_pump(const struct state *st)
{
if (st->mstate == BREWING)
relay(PIN_PUMP, ON);
else
relay(PIN_PUMP, OFF);
}
void do_output(const struct state *st)
{
output_leds(st);
output_heater(st);
}
void setup()
{
Serial.begin(9600);
Serial.println("Booting");
pinMode(PIN_POWER_ON, INPUT);
pinMode(PIN_HOT, INPUT);
pinMode(PIN_LED_RED, OUTPUT);
pinMode(PIN_LED_GREEN, OUTPUT);
pinMode(PIN_HEAT, OUTPUT);
pinMode(PIN_PUMP, OUTPUT);
/* Turn all relays off */
relay(PIN_HEAT, OFF);
relay(PIN_PUMP, OFF);
Serial.println("Ready");
}
void loop()
{
do_input(&g_in);
do_proc(&g_st, &g_in);
do_output(&g_st);
delay(5);
}