reflow/reflowctl/reflowctl.ino

// include the library code:
#include <LiquidCrystal.h>
#include <DFR_Key.h>

// states
#define CONFIG_STATE 0
#define START_STATE 1
#define PREHEAT_STATE 2
#define RAMP_UP_STATE 3
#define TAL_FIRST_STATE 4
#define PEAK_STATE 5
#define TAL_SECOND_STATE 6
#define RAMP_DOWN_STATE 7
#define END_STATE 8
#define ERROR_STATE 9

// error conditions
#define E_DT_MIN 1 // temperature dt too small
#define E_DT_MAX 2 // temperature dt too big
#define E_TIME_MAX 4 // reflow process does take too long
#define E_TS_TOO_SHORT 8 // Ts duration too short
#define E_TS_TOO_LONG 16 // Ts duration too long
#define E_TL_TOO_SHORT 32 // Tl duration too short
#define E_TL_TOO_LONG 64 // Tl duration too long
#define E_TP_TOO_SHORT 128 // Tp duration too short
#define E_TP_TOO_LONG 256 // Tp duration too long

// system time, timestamps and temperatures from sensors
unsigned int time = 0; // profile seconds
unsigned int temperature = 25; // actual oven temp
unsigned int last_temperature = 25; // last oven temp
int actual_dt = 0; // actual difference from last to actual temperatur


typedef struct {
  // profile temperatures
  unsigned int Ts_min;
  unsigned int Ts_max;
  unsigned int Tl;
  unsigned int Tp;
  unsigned int time_max;

  // profile temp per second rates
  int ramp_up_rate_min;
  int ramp_up_rate_max;
  int ramp_down_max;
  int ramp_down_min;

  // profile temp durations
  unsigned int Ts_duration_min;
  unsigned int Ts_duration_max;
  unsigned int Tl_duration_min;
  unsigned int Tl_duration_max;
  unsigned int Tp_duration_min;
  unsigned int Tp_duration_max;
} Profile;

struct Profile profile {150, // °C
  unsigned int Ts_max = 200; // °C
  unsigned int Tl = 217; // 217°C
  unsigned int Tp = 260; // 245-260°C
  unsigned int time_max = 480; // 8*60s max

  // profile temp per second rates
  int ramp_up_rate_min = 0; // not used yet
  unsigned int ramp_up_rate_max = 50; // 3°C/s
  unsigned int ramp_down_max = 6; // 6°C/s max
  unsigned int ramp_down_min = 2; // 2°C/s max

  // profile temp durations
  unsigned int Ts_duration_min = 60; // s
  unsigned int Ts_duration_max = 180; // s
  unsigned int Tl_duration_min = 60; // 60-150s
  unsigned int Tl_duration_max = 150; // 60-150s
  unsigned int Tp_duration_min = 20; // 20-40s
  unsigned int Tp_duration_max = 40; // 20-40s
} Profile;

// timestamps of event beginnings/ends
unsigned int Ts_time_start = 0;
unsigned int Ts_time_end = 0;
unsigned int Tl_time_start = 0;
unsigned int Tl_time_end = 0;
unsigned int Tp_time_start = 0;
unsigned int Tp_time_end = 0;

// thermostat
static unsigned int set_min = 0;
static unsigned int set_max = 0;
static int set_dt_min = 0;
static int set_dt_max = 0;


// state machine
static unsigned int error_condition = 0;
static byte state = 0;
static boolean is_oven_heating = false;

// ui stuff
static boolean led_on = false;
static boolean disable_checks = true;

//Pin assignments for SainSmart LCD Keypad Shield
static LiquidCrystal lcd(8, 9, 4, 5, 6, 7);
static DFR_Key keypad;

void setup() {
  Serial.begin(9600);
  delay(300);
  pinMode(13, OUTPUT);
  pinMode(2, INPUT);
  set_start_state();

  lcd.begin(16, 2);
  lcd.clear();
  keypad.setRate(10);
}


void print_profile_state() {
  String tmp("Profile: ");
  tmp += state;
  tmp += "/";
  tmp += END_STATE;
  lcd.setCursor(0, 1);
  lcd.print(tmp);
}

void print_status() {
  String tmp("T: ");
  if (time < 10)
    tmp += "00";
  else if (time < 100)
    tmp += "0";
  tmp += time;
  tmp += " Tmp: ";
  if (temperature < 10)
    tmp += "00";
  else if (temperature < 100)
    tmp += "0";
  tmp += temperature;
  lcd.setCursor(0, 0);
  lcd.print(tmp);
}

void print_config_state() {

  for (;;) {

  }
}

/* led edit mode procedures
 * global menu (up/down) -> select
 *  start
 *  edit profile
 *    select value (up/down) -> select | left
 *      value (up/down) -> select | left
 *
 */


void get_time() {
  if (state>0)
    time++;
}

void control_oven() {
  if (temperature < set_min && !is_oven_heating) {
    is_oven_heating = true;
    Serial.println("Oven turned on");
  }
  else if (temperature > set_min && is_oven_heating) {
    is_oven_heating = false;
    Serial.println("Oven turned off");
  }
}


void set_temp(int min, int max, int dt_min, int dt_max) {
  set_min = min;
  set_max = max;
  set_dt_min = dt_min;
  set_dt_max = dt_max;
}


void get_temp() {
  last_temperature = temperature;
  temperature = int(float(analogRead(2)) * 0.2929);
  actual_dt = temperature - last_temperature;
}


void check_dt() {
  if (disable_checks)
    return;
  if (actual_dt > set_dt_max) {
    error_condition |= E_DT_MAX;
  }
  if (actual_dt < set_dt_min) {
    error_condition |= E_DT_MIN;
  }
}

void print_debug() {
  Serial.print("Time: ");
  Serial.print(time);
  Serial.print(", temperatur: ");
  Serial.print(temperature);
  Serial.print(", last_temperatur: ");
  Serial.print(last_temperature);
  Serial.print(", state: ");
  Serial.print(state);
  Serial.print(", Error: ");
  Serial.println(error_condition);
}


void check_max_duration() {
  if (disable_checks)
    return;
  Serial.println(time);
  if (time > time_max) {
    error_condition |= E_TIME_MAX;
  }
  Serial.println(time);
}

void check_Ts_duration_min() {
  if (disable_checks)
    return;
  Tl_time_end = time;
  if (time - Tl_time_start < Tl_duration_min) {
    error_condition |= E_TL_TOO_SHORT;
  }
}

void check_Ts_duration_max() {
  if (disable_checks)
    return;
  if (time - Ts_time_start > Tl_duration_max) {
    error_condition |= E_TS_TOO_LONG;
  }
}


void check_Tl_duration_min() {
  if (disable_checks)
    return;
  Tl_time_end = time;
  if (time - Tl_time_start < Tl_duration_min) {
    error_condition |= E_TL_TOO_SHORT;
  }
}

void check_Tl_duration_max() {
  if (disable_checks)
    return;
  if (time - Tl_time_start > Tl_duration_max) {
    error_condition |= E_TL_TOO_LONG;
  }
}

void check_Tp_duration_min() {
  Tp_time_end = time;
  if (time - Tp_time_start < Tp_duration_min) {
    error_condition |= E_TP_TOO_SHORT;
  }
}

void check_Tp_duration_max() {
  if (disable_checks)
    return;
  if (time - Tp_time_start > Tp_duration_max) {
    error_condition |= E_TP_TOO_LONG;
  }
}

void set_start_state() {
  led_on = false;
  digitalWrite(13, LOW);
  error_condition = 0;
  state = START_STATE;
  get_temp();
  last_temperature = temperature;
  actual_dt = temperature - last_temperature;
  set_temp(Tp-5, Tp, 0, ramp_up_rate_max);
}


void set_preheat_state() {
  Serial.println("Changing state to PREHEAT_STATE");
  state++;
}


void set_ramp_up_state() {
  Serial.println("Changed state to RAMP_UP_STATE");
  state++;
}


void set_tal_first_state() {
  Serial.println("Changed state to TAL_FIRST_STATE");
  state++;
}


void set_peak_state() {
  Serial.println("Changed state to PEAK_STATE");
  state++;
}


void set_tal_second_state() {
  Serial.println("Changed state to TAL_SECOND_STATE");
  set_temp(25, 25, -3, -6);
  state++;
}


void set_ramp_down_state() {
  Serial.println("Changed state to RAMP_DOWN_STATE");
  state++;
}


void set_end_state() {
  Serial.println("Changed state to END_STATE");
  state++;
}


void set_error_state() {
  if (state != ERROR_STATE) {
    Serial.println("Changed state to ERROR_STATE");
    set_temp(0, 0, 0, 0);
    state = ERROR_STATE;
  }
}


void handle_start_state() {
  check_max_duration();
  Serial.println(time);
   if (temperature > Ts_min) {
    Ts_time_start = time;
    set_preheat_state();
  }
}


void handle_preheat_state() {
  check_Ts_duration_max();
  check_max_duration();
  if (temperature > Ts_max) {
    check_Ts_duration_min();
    set_ramp_up_state();
  }
}


void handle_ramp_up_state() {
  check_max_duration();
  if (temperature > Tl) {
    Tl_time_start = time;
    set_tal_first_state();
  }
}


void handle_tal_first_state() {
  check_max_duration();
  check_Tl_duration_max();
  if (temperature > Tp - 5) {
    Tp_time_start = time;
    set_peak_state();
  }
}


void handle_peak_state() {
  check_Tl_duration_max();
  check_Tp_duration_max();
  if (time - Tp_time_start > Tp_duration_max) {
    check_Tp_duration_min();
    set_tal_second_state();
   }
}


void handle_tal_second_state() {
  check_Tl_duration_max();
  if (temperature < Tl) {
    check_Tl_duration_min();
    set_ramp_down_state();
  }
}

void handle_ramp_down_state() {
  if (temperature < Ts_min) {
    set_end_state();
  }
}


void handle_end_state() {
//   while(true) {
//     continue;
//   }
}



void handle_error_state() {
  if (led_on) {
    digitalWrite(13, LOW);
    led_on = false;
  }
  else {
    digitalWrite(13, HIGH);
    led_on = true;
  }
  if (error_condition & E_DT_MIN)
    Serial.println("Error: delta °K/second too low");
  if (error_condition & E_DT_MAX)
    Serial.println("Error: delta °K/second too big");
  if (error_condition & E_TIME_MAX)
    Serial.println("Error: reflow process does take too long");
  if (error_condition & E_TS_TOO_SHORT)
    Serial.println("Error: heatup duration was too short");
  if (error_condition & E_TS_TOO_LONG)
    Serial.println("Error: heatup duration was too long");
  if (error_condition & E_TL_TOO_SHORT)
    Serial.println("Error: temperature above liquidus duration was too short");
  if (error_condition & E_TL_TOO_LONG)
    Serial.println("Error: temperature above liquidus duration was too long");
  if (error_condition & E_TP_TOO_LONG)
    Serial.println("Error: peak temperature duration was too short");
  if (error_condition & E_TP_TOO_SHORT)
    Serial.println("Error: peak temperature duration was too long");
}


void loop() {
  get_time();
  get_temp();
  check_dt();

  if (!error_condition) {
    print_debug();
  }
  else {
    set_error_state();
  }

  switch (state) {
      case CONFIG_STATE:
        handle_config_state();
        print_config_state()
        break;
      case START_STATE:
        handle_start_state();
        break;
      case PREHEAT_STATE:
        handle_preheat_state();
        break;
      case RAMP_UP_STATE:
        handle_ramp_up_state();
        break;
      case TAL_FIRST_STATE:
        handle_tal_first_state();
        break;
      case PEAK_STATE:
        handle_peak_state();
        break;
      case TAL_SECOND_STATE:
        Tl_time_end = time;
        handle_tal_second_state();
        break;
      case RAMP_DOWN_STATE:
        handle_ramp_down_state();
        break;
      case END_STATE:
        handle_end_state();
        break;
      case ERROR_STATE:
        handle_error_state();
        break;
      default:
        break;
  }

  control_oven();
//   lcd.clear();
  print_debug();
  print_status();
  print_profile_state();
  delay(1000);
}