Changeset - c02f990f1d3e
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Ethan Zonca - 10 years ago 2014-11-14 23:05:11
ez@ethanzonca.com
Start prototyping multiple setpoint support
1 file changed with 62 insertions and 0 deletions:
main.c
62
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main.c
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@@ -170,384 +170,446 @@ void update_temp() {
 
 
    // Deassert CS
 
    delay(1);
 
    GPIO_SetBits(MAX_CS);
 
}
 
 
 
// PID implementation
 
// TODO: Make struct that has the last_temp and i_state in it, pass by ref. Make struct that has other input values maybe.
 
int16_t last_pid_temp = 0;
 
uint8_t last_pid_temp_frac = 0;
 
int16_t i_state = 0;
 
 
int16_t update_pid(uint16_t k_p, uint16_t k_i, uint16_t k_d, int16_t temp, uint8_t temp_frac, int16_t setpoint)
 
{
 
  // Calculate instantaneous error
 
  int16_t error = (int16_t)setpoint - (int16_t)temp; // TODO: Use fixed point fraction
 
 
  // Proportional component
 
  int16_t p_term = k_p * error;
 
 
  // Error accumulator (integrator)
 
  i_state += error;
 
 
  // to prevent the iTerm getting huge despite lots of
 
  //  error, we use a "windup guard"
 
  // (this happens when the machine is first turned on and
 
  // it cant help be cold despite its best efforts)
 
  // not necessary, but this makes windup guard values
 
  // relative to the current iGain
 
  int16_t windup_guard_res = windup_guard / k_i;
 
 
  // Calculate integral term with windup guard
 
  if (i_state > windup_guard_res)
 
    i_state = windup_guard_res;
 
  else if (i_state < -windup_guard_res)
 
    i_state = -windup_guard_res;
 
  int16_t i_term = k_i * i_state;
 
 
  // Calculate differential term (slope since last iteration)
 
  int16_t d_term = (k_d * (temp - last_pid_temp));
 
 
  // Save temperature for next iteration
 
  last_pid_temp = temp;
 
  last_pid_temp_frac = temp_frac;
 
 
  int16_t result = p_term + i_term - d_term;
 
 
  // Put out tenths of percent, 0-1000.
 
  if(result > 1000)
 
    result = 1000;
 
  else if(result < -1000)
 
    result = -1000;
 
 
  // Return feedback
 
  return result;
 
}
 
 
 
uint32_t last_ssr_on = 0;
 
uint32_t last_led = 0;
 
int32_t setpoint = 0;
 
int16_t ssr_output = 0; // Duty cycle of ssr, 0 to SSR_PERIOD
 
uint8_t pid_enabled = 0;
 
 
// Process things
 
void process()
 
{
 
    update_temp(); // Read MAX31855
 
 
    // TODO: Add calibration offset (linear)
 
 
    if(ticks - last_led > 400)
 
    {
 
        GPIO_ToggleBits(LED_POWER);
 
        last_led = ticks;
 
    }
 
 
    // Every 200ms, set the SSR on unless output is 0
 
    if((ticks - last_ssr_on > SSR_PERIOD))
 
    {
 
        if(pid_enabled)
 
        {
 
            // Get ssr output for next time
 
            int16_t power_percent = update_pid(k_p, k_i, k_d, temp, temp_frac, setpoint);
 
            //power-percent is 0-1000
 
            ssr_output = power_percent; //(((uint32_t)SSR_PERIOD * (uint32_t)10 * (uint32_t)100) * power_percent) / (uint32_t)1000000;
 
        }
 
        else
 
        {
 
            ssr_output = 0;
 
        }
 
 
        // Only support heating (ssr_output > 0) right now
 
        if(ssr_output > 0) {
 
 
            char tempstr[6];
 
            itoa(ssr_output, tempstr);
 
            ssd1306_DrawString(tempstr, 0, 90);
 
 
            GPIO_SetBits(LED_STAT);
 
            GPIO_SetBits(SSR_PIN);
 
            last_ssr_on = ticks;
 
        }
 
    }
 
 
    // Kill SSR after elapsed period less than SSR_PERIOD
 
    if(ticks - last_ssr_on > ssr_output || ssr_output == 0)
 
    {
 
        GPIO_ResetBits(LED_STAT);
 
        GPIO_ResetBits(SSR_PIN);
 
    }
 
}
 
 
void draw_setpoint() {
 
    char tempstr[3];
 
    itoa_fp(temp, temp_frac, tempstr);
 
    ssd1306_DrawStringBig("      ", 3, 0);
 
    ssd1306_DrawStringBig(tempstr, 3, 0);
 
    ssd1306_DrawStringBig(">", 3, 74);
 
    itoa(setpoint, tempstr);
 
    ssd1306_DrawStringBig("    ", 3, 90);
 
    ssd1306_DrawStringBig(tempstr, 3, 90);
 
}
 
 
uint8_t goto_mode = 2;
 
 
// State machine
 
uint8_t sw_btn_last = 0;
 
uint8_t sw_up_last = 0;
 
uint8_t sw_down_last = 0;
 
uint8_t sw_left_last = 0;
 
uint8_t sw_right_last = 0;
 
 
#define SW_BTN_PRESSED (sw_btn_last == 0 && sw_btn == 1) // rising edge on buttonpress
 
#define SW_UP_PRESSED (sw_up_last == 0 && sw_up == 1)
 
#define SW_DOWN_PRESSED (sw_down_last == 0 && sw_down == 1)
 
#define SW_LEFT_PRESSED (sw_left_last == 0 && sw_left == 1)
 
#define SW_RIGHT_PRESSED (sw_right_last == 0 && sw_right == 1)
 
 
void save_settings()
 
{
 
   Minimal_EEPROM_Unlock();
 
    // Try programming a word at an address divisible by 4
 
    Minimal_EEPROM_ProgramWord(EEPROM_BASE_ADDR + EEPROM_ADDR_BOOTTOBREW, boottobrew);
 
    Minimal_EEPROM_ProgramWord(EEPROM_BASE_ADDR + EEPROM_ADDR_WINDUP_GUARD, windup_guard);
 
    Minimal_EEPROM_ProgramWord(EEPROM_BASE_ADDR + EEPROM_ADDR_K_P, k_p);
 
    Minimal_EEPROM_ProgramWord(EEPROM_BASE_ADDR + EEPROM_ADDR_K_I, k_i);
 
    Minimal_EEPROM_ProgramWord(EEPROM_BASE_ADDR + EEPROM_ADDR_K_D, k_d);
 
    Minimal_EEPROM_Lock();
 
}
 
 
void save_setpoints()
 
{
 
 
    Minimal_EEPROM_Unlock();
 
    Minimal_EEPROM_ProgramWord(EEPROM_BASE_ADDR + EEPROM_ADDR_BREWTEMP, setpoint_brew);
 
    Minimal_EEPROM_ProgramWord(EEPROM_BASE_ADDR + EEPROM_ADDR_STEAMTEMP, setpoint_steam);
 
    Minimal_EEPROM_Lock();
 
}
 
 
 
// TODO: Make a struct that has all settings in it. Pass by ref to this func in a library.
 
void restore_settings()
 
{
 
    Minimal_EEPROM_Unlock();
 
    while(Minimal_FLASH_GetStatus()==FLASH_BUSY);
 
    boottobrew = (*(__IO uint32_t*)(EEPROM_BASE_ADDR + EEPROM_ADDR_BOOTTOBREW));
 
 
    while(Minimal_FLASH_GetStatus()==FLASH_BUSY);
 
    windup_guard = (*(__IO uint32_t*)(EEPROM_BASE_ADDR + EEPROM_ADDR_WINDUP_GUARD));
 
 
    while(Minimal_FLASH_GetStatus()==FLASH_BUSY);
 
    k_p = (*(__IO uint32_t*)(EEPROM_BASE_ADDR + EEPROM_ADDR_K_P));
 
 
    while(Minimal_FLASH_GetStatus()==FLASH_BUSY);
 
    k_i = (*(__IO uint32_t*)(EEPROM_BASE_ADDR + EEPROM_ADDR_K_I));
 
 
    while(Minimal_FLASH_GetStatus()==FLASH_BUSY);
 
    k_d = (*(__IO uint32_t*)(EEPROM_BASE_ADDR + EEPROM_ADDR_K_D));
 
 
    while(Minimal_FLASH_GetStatus()==FLASH_BUSY);
 
    setpoint_brew = (*(__IO uint32_t*)(EEPROM_BASE_ADDR + EEPROM_ADDR_BREWTEMP));
 
 
    while(Minimal_FLASH_GetStatus()==FLASH_BUSY);
 
    setpoint_steam = (*(__IO uint32_t*)(EEPROM_BASE_ADDR + EEPROM_ADDR_STEAMTEMP));
 
 
    Minimal_EEPROM_Lock();
 
}
 
 
int16_t last_temp = 21245;
 
 
 
///////////////////////////////////////////////////////////////////////////////////////
 
/// freaking multiple setpoint support ///
 
uint8_t step_duration[10];
 
int16_t step_setpoint[10];
 
uint8_t final_setpoint = 0;
 
 
void stepper_init()
 
{
 
    int i;
 
    for(i=0; i<10; i++)
 
    {
 
        step_duration[i] = 0;
 
        step_setpoint[i] = 0;
 
    }
 
}
 
 
void state_setstepper()
 
{
 
    // Write text to OLED
 
    // [ step #1:: Duration: ### ]
 
    // [           Setpoint: ### ]
 
    char tempstr[6];
 
 
    itoa(stepnum, tempstr);
 
    ssd1306_DrawString("Step #", 0, 0);
 
    ssd1306_DrawString(tempstr, 0, 40);
 
 
    ssd1306_DrawString("Duration: ", 0, 5);
 
    itoa(step_duration[final_setpoint], tempstr);
 
    ssd1306_DrawString(tempstr, 0, 70);
 
 
    ssd1306_DrawString("Setpoint: ", 0, 0);
 
    itoa(step_setpoint[final_setpoint], tempstr);
 
    itoa(stepnum, tempstr);
 
 
    ssd1306_DrawString("Press to accept", 3, 40);
 
 
    // Button handler - TODO: increment max_step if pressed
 
    // return and go to next state otherwise
 
    if(SW_BTN_PRESSED) {
 
        state = STATE_SETSTEPPER;
 
        final_setpoint++
 
    }
 
    else if(SW_LEFT_PRESSED) {
 
        state++; // go to next state or something
 
    }
 
    else {
 
        user_input(&k_p);
 
    }
 
 
    // Event Handler
 
    // N/A
 
}
 
 
// Multiple screens to set setpoint and duration on each screen
 
// press center to go to the next one, and press left or right or something to confirm
 
 
// When executing, complete on time AND(?) temperature. Maybe allow switching to OR via settings
 
 
////////////////////////////////////////////////////////////////////////////////////////////////
 
 
void machine()
 
{
 
    uint8_t last_state = state;
 
 
    uint8_t temp_changed = temp != last_temp;
 
    last_temp = temp;
 
 
    uint8_t sw_btn = !GPIO_ReadInputDataBit(SW_BTN);
 
    uint8_t sw_up = !GPIO_ReadInputDataBit(SW_UP);
 
    uint8_t sw_down = !GPIO_ReadInputDataBit(SW_DOWN);
 
    uint8_t sw_left = !GPIO_ReadInputDataBit(SW_LEFT);
 
    uint8_t sw_right = !GPIO_ReadInputDataBit(SW_RIGHT);
 
 
    switch(state)
 
    {
 
        // Idle state
 
        case STATE_IDLE:
 
        {
 
            // Write text to OLED
 
            // [ therm :: idle ]
 
            ssd1306_DrawString("therm :: idle ", 0, 40);
 
            pid_enabled = 0;
 
 
            if(temp_changed) {
 
                char tempstr[6];
 
                itoa_fp(temp, temp_frac, tempstr);
 
                ssd1306_DrawString("Temp: ", 3, 40);
 
                ssd1306_DrawString("    ", 3, 72);
 
                ssd1306_DrawString(tempstr, 3, 72);
 
            }
 
 
            ssd1306_drawlogo();
 
 
            switch(goto_mode) {
 
                case 2:
 
                {
 
                    ssd1306_DrawString("-> brew     ", 1, 40);
 
                } break;
 
 
                case 1:
 
                {
 
                    ssd1306_DrawString("-> setup    ", 1, 40);
 
                } break;
 
 
                case 0:
 
                {
 
                    ssd1306_DrawString("-> reset    ", 1, 40);
 
                } break;
 
            }
 
 
            // Button handler
 
            if(SW_BTN_PRESSED) {
 
                switch(goto_mode) {
 
                    case 2:
 
                        state = STATE_PREHEAT_BREW;
 
                        break;
 
                    case 1:
 
                        state = STATE_SETP;
 
                        break;
 
                    case 0:
 
                        state = STATE_IDLE;
 
                        break;
 
                    default:
 
                        state = STATE_PREHEAT_BREW;
 
                }
 
            }
 
            else if(SW_UP_PRESSED && goto_mode < 2) {
 
                goto_mode++;
 
            }
 
            else if(SW_DOWN_PRESSED && goto_mode > 0) {
 
                goto_mode--;
 
            }
 
 
 
            // Event Handler
 
            // N/A
 
 
        } break;
 
 
        case STATE_SETP:
 
        {
 
            // Write text to OLED
 
            // [ therm :: set p ]
 
            // [ p = 12         ]
 
            ssd1306_DrawString("Proportional", 0, 40);
 
            ssd1306_drawlogo();
 
 
            char tempstr[6];
 
            itoa(k_p, tempstr);
 
            ssd1306_DrawString("P=", 1, 45);
 
            ssd1306_DrawString("    ", 1, 57);
 
            ssd1306_DrawString(tempstr, 1, 57);
 
 
            ssd1306_DrawString("Press to accept", 3, 40);
 
 
            // Button handler
 
            if(SW_BTN_PRESSED) {
 
                state = STATE_SETI;
 
            }
 
            else {
 
                user_input(&k_p);
 
            }
 
 
            // Event Handler
 
            // N/A
 
 
        } break;
 
 
        case STATE_SETI:
 
        {
 
            // Write text to OLED
 
            // [ therm :: set i ]
 
            // [ i = 12         ]
 
            ssd1306_DrawString("Integral", 0, 40);
 
            ssd1306_drawlogo();
 
 
            char tempstr[6];
 
            itoa(k_i, tempstr);
 
            ssd1306_DrawString("I=", 1, 45);
 
            ssd1306_DrawString("    ", 1, 57);
 
            ssd1306_DrawString(tempstr, 1, 57);
 
 
            ssd1306_DrawString("Press to accept", 3, 40);
 
 
            // Button handler
 
            if(SW_BTN_PRESSED) {
 
                state = STATE_SETD;
 
            }
 
            else {
 
                user_input(&k_i);
 
            }
 
 
            // Event Handler
 
            // N/A
 
 
        } break;
 
 
        case STATE_SETD:
 
        {
 
            // Write text to OLED
 
            // [ therm :: set d ]
 
            // [ d = 12         ]
 
            ssd1306_DrawString("Derivative", 0, 40);
 
            ssd1306_drawlogo();
 
 
            char tempstr[6];
 
            itoa(k_d, tempstr);
 
            ssd1306_DrawString("D=", 1, 45);
 
            ssd1306_DrawString("    ", 1, 57);
 
            ssd1306_DrawString(tempstr, 1, 57);
 
 
            ssd1306_DrawString("Press to accept", 3, 40);
 
 
            // Button handler
 
            if(SW_BTN_PRESSED) {
 
                state = STATE_SETWINDUP;
 
            }
 
            else {
 
                user_input(&k_d);
 
            }
 
 
            // Event Handler
 
            // N/A
 
 
        } break;
 
 
        case STATE_SETWINDUP:
 
        {
 
            // Write text to OLED
 
            // [ therm :: set windup ]
 
            // [ g = 12         ]
 
            ssd1306_DrawString("Windup Guard", 0, 40);
 
            ssd1306_drawlogo();
 
 
            char tempstr[6];
 
            itoa(windup_guard, tempstr);
 
            ssd1306_DrawString("G=", 1, 45);
 
            ssd1306_DrawString("    ", 1, 57);
 
            ssd1306_DrawString(tempstr, 1, 57);
 
 
            ssd1306_DrawString("Press to accept", 3, 40);
 
 
            // Button handler
 
            if(SW_BTN_PRESSED) {
 
                state = STATE_SETBOOTTOBREW;
 
            }
 
            else {
 
                user_input(&windup_guard);
 
            }
 
 
            // Event Handler
 
            // N/A
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