Changeset - f4ef22eb5176
[Not reviewed]
cortex-f0
0 3 0
Ethan Zonca - 9 years ago 2015-06-01 17:18:30
ez@ethanzonca.com
Added support for detecting which thermocouple error occurred
3 files changed with 13 insertions and 3 deletions:
0 comments (0 inline, 0 general)
display.c
Show inline comments
 
@@ -405,166 +405,173 @@ void display_process(therm_settings_t* s
 
                status->state = STATE_IDLE;
 
            }
 
            else {
 
                user_input(&set->setpoint_brew);
 
            }
 

	
 
            // Event Handler
 
            if(status->temp >= status->setpoint) {
 
                status->state = STATE_MAINTAIN_BREW;
 
            }
 
 
 
        } break;
 

	
 
        case STATE_MAINTAIN_BREW:
 
        {
 
            // Write text to OLED
 
            // [ therm : ready to brew ]
 
            // [ 30 => 120 C           ]
 
            ssd1306_DrawString("Preheated!", 0, 0);
 
            //ssd1306_drawlogo();
 
            draw_setpoint(status);
 
            status->pid_enabled = 1;
 
	    status->setpoint = set->setpoint_brew;
 

	
 
            // Button handler
 
            if(SW_BTN_PRESSED) {
 
		save_setpoints(); // TODO: Check for mod
 
                status->state = STATE_IDLE;
 
            }
 
            else {
 
                user_input(&set->setpoint_brew);
 
            }
 

	
 
            // Event Handler
 
            // N/A
 
 
 
        } break;
 

	
 
        case STATE_PREHEAT_STEAM:
 
        {
 
            // Write text to OLED
 
            // [ therm : preheating steam ]
 
            // [ 30 => 120 C           ]
 
            ssd1306_DrawString("Preheating...", 0, 0);
 
            //ssd1306_drawlogo();
 
            draw_setpoint(status);
 
            status->pid_enabled = 1;
 
	    status->setpoint = set->setpoint_steam;
 
	    
 
            // Button handler
 
            if(SW_BTN_PRESSED) {
 
                status->state = STATE_IDLE;
 
		save_setpoints(); // TODO: Check for mod
 
            }
 
            else {
 
                user_input(&set->setpoint_steam);
 
            }
 

	
 
            // Event Handler
 
            if(status->temp >= status->setpoint) {
 
                status->state = STATE_MAINTAIN_STEAM;
 
            }
 
 
 
        } break;
 

	
 
        case STATE_MAINTAIN_STEAM:
 
        {
 
            // Write text to OLED
 
            // [ therm : ready to steam ]
 
            // [ 30 => 120 C            ]
 
            ssd1306_DrawString("Ready to Steam!", 0, 0);
 
            //ssd1306_drawlogo();
 
            draw_setpoint(status);
 
            status->pid_enabled = 1;
 
	    status->setpoint = set->setpoint_steam;
 

	
 
            // Button handler
 
            if(SW_BTN_PRESSED) {
 
                status->state = STATE_IDLE;
 
		save_setpoints(); // TODO: Check for mod
 
            }
 
            else {
 
                user_input(&set->setpoint_steam);
 
            }
 

	
 
            // Event Handler
 
            // N/A
 
 
 
        } break;
 

	
 
        case STATE_TC_ERROR:
 
        {
 
            // Write text to OLED
 
            // [ therm : ready to steam ]
 
            // [ 30 => 120 C            ]
 
            ssd1306_DrawString("Error:", 0, 0);
 
            ssd1306_DrawString("Connect thermocouple", 1, 0);
 

	
 
            if(status->tc_errno == 1)
 
                ssd1306_DrawString("#1, Check Sensor", 1, 0);
 
            else if(status->tc_errno == 4)
 
                ssd1306_DrawString("#4, Check Sensor", 1, 0);
 
            else
 
                ssd1306_DrawString("#?, Unknown Error", 1, 0);
 

	
 
            ssd1306_DrawString("Press -> to ignore", 3, 0);
 

	
 
            // Button handler
 
            if(SW_BTN_PRESSED) {
 
                status->state = STATE_IDLE;
 
            }
 
            else if(SW_RIGHT_PRESSED) {
 
                set->ignore_tc_error = 1;
 
                status->state = STATE_IDLE;
 
            }
 
            // Event Handler
 
            // Maybe handle if TC is plugged in
 
            // N/A
 
 
 
        } break;
 

	
 
        // Something is terribly wrong
 
        default:
 
        {
 
            status->state = STATE_IDLE;
 
            status->pid_enabled = 0;
 

	
 
        } break;
 
            
 
    }
 

	
 
    if(last_state != status->state) {
 
        // Clear screen on state change
 
        goto_mode = 2;
 
        trigger_drawsetpoint = 1;
 
        ssd1306_clearscreen();
 
    }
 

	
 
    // Last buttonpress
 
    sw_btn_last = sw_btn;
 
    sw_up_last = sw_up;
 
    sw_down_last = sw_down;
 
    sw_left_last = sw_left;
 
    sw_right_last = sw_right;
 
}
 

	
 

	
 
int32_t temp_last = 43002;
 
int32_t setpoint_last = 10023;
 
void draw_setpoint(therm_status_t* status) {
 
    // FIXME: need to do this when switching modes too
 
    if(status->temp != temp_last || trigger_drawsetpoint) { 
 
        char tempstr[3];
 
        itoa_fp(status->temp, status->temp_frac, tempstr);
 
        ssd1306_DrawStringBig("      ", 3, 0);
 
        ssd1306_DrawStringBig(tempstr, 3, 0);
 
    }
 

	
 
    if(trigger_drawsetpoint) 
 
        ssd1306_DrawStringBig(">", 3, 74);
 

	
 
    if(status->setpoint != setpoint_last || trigger_drawsetpoint) {
 
        char tempstr[3];
 
        itoa(status->setpoint, tempstr, 10);
 
        ssd1306_DrawStringBig("   ", 3, 90);
 
        ssd1306_DrawStringBig(tempstr, 3, 90);
 
    }
 

	
 
    trigger_drawsetpoint = 0;
 
    setpoint_last = status->setpoint;
 
    temp_last = status->temp;
 
}
 

	
 
// vim:softtabstop=4 shiftwidth=4 expandtab 
main.c
Show inline comments
 
@@ -69,199 +69,201 @@ int main(void)
 
    ssd1306_Init();
 
    ssd1306_clearscreen();
 
   
 
    // Default settings 
 
    set.boottobrew = 0;
 
    set.temp_units = TEMP_UNITS_CELSIUS;
 
    set.windup_guard = 1;
 
    set.k_p = 1;
 
    set.k_i = 1;
 
    set.k_d = 1;
 
    set.ignore_tc_error = 0;
 
    set.setpoint_brew = 0;
 
    set.setpoint_steam = 0;
 
 
    // Default status
 
    status.temp = 0;
 
    status.temp_frac = 0;
 
    status.state_resume = 0;
 
    status.state = STATE_IDLE;
 
    status.setpoint = 0;
 
    status.pid_enabled = 0;
 
 
    // Load settings (if any) from EEPROM
 
    restore_settings();
 
 
    if(set.boottobrew)
 
      status.state = STATE_PREHEAT_BREW; // Go to brew instead of idle if configured thusly
 
 
    // Startup screen 
 
    ssd1306_DrawString("therm v0.1", 1, 40);
 
    ssd1306_DrawString("protofusion.org/therm", 3, 0);
 
 
    HAL_Delay(1500);
 
    ssd1306_clearscreen();
 
 
 
    // Main loop
 
    while(1)
 
    {
 
        // Process sensor inputs
 
        process();
 
 
        // Run state machine
 
        display_process(&set, &status); 
 
    }
 
 
}
 
 
/** System Clock Configuration
 
*/
 
void SystemClock_Config(void)
 
{
 
 
  RCC_OscInitTypeDef RCC_OscInitStruct;
 
  RCC_ClkInitTypeDef RCC_ClkInitStruct;
 
  RCC_PeriphCLKInitTypeDef PeriphClkInit;
 
 
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI48;
 
  RCC_OscInitStruct.HSI48State = RCC_HSI48_ON;
 
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
 
  HAL_RCC_OscConfig(&RCC_OscInitStruct);
 
 
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_SYSCLK;
 
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI48;
 
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
 
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
 
  HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1);
 
 
  PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_USB;
 
  PeriphClkInit.UsbClockSelection = RCC_USBCLKSOURCE_HSI48;
 
  HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit);
 
 
  __SYSCFG_CLK_ENABLE();
 
 
}
 
 
 
 
void update_temp() {
 
 
    // Assert CS
 
    HAL_GPIO_WritePin(MAX_CS, 0);
 
 
    uint8_t rxdatah[1] = {0x00};
 
    uint8_t rxdatal[1] = {0x00};
 
 
    HAL_SPI_Receive(&hspi1, rxdatah, 1, 100);
 
    HAL_SPI_Receive(&hspi1, rxdatal, 1, 100);
 
 
    // Release CS
 
    HAL_GPIO_WritePin(MAX_CS, 1);
 
 
    // Assemble data array into one var
 
    uint16_t temp_pre = rxdatal[0] | (rxdatah[0]<<8);
 
 
    if(temp_pre & 0b0000000000000010) {
 
        ssd1306_clearscreen();
 
        //ssd1306_DrawString("Fatal Error", 3, 35);
 
        HAL_Delay(100);
 
        HAL_Delay(100); // FIXME: remove?
 
        status.tc_errno = 4;
 
        status.state = STATE_TC_ERROR;
 
        status.temp = 0;
 
        status.temp_frac = 0;
 
    }
 
    else if(temp_pre & 0b0000000000000001 && !set.ignore_tc_error) {
 
        status.tc_errno = 1;
 
        HAL_Delay(100); // FIXME: remove?
 
        status.state_resume = status.state;
 
        status.state = STATE_TC_ERROR;
 
        status.temp = 0;
 
        status.temp_frac = 0;
 
    }
 
    else 
 
    {
 
        if(status.state == STATE_TC_ERROR)
 
        {
 
            status.state = status.state_resume;
 
            ssd1306_clearscreen();
 
        }
 
 
        uint8_t sign = status.temp >> 15;// top bit is sign
 
 
        temp_pre = temp_pre >> 2; // Drop 2 lowest bits
 
        status.temp_frac = temp_pre & 0b11; // get fractional part
 
        status.temp_frac *= 25; // each bit is .25 a degree, up to fixed point
 
        temp_pre = temp_pre >> 2; // Drop 2 fractional bits 
 
 
        int8_t signint;
 
 
        if(sign) {
 
            signint = -1;
 
        }
 
        else {
 
            signint = 1;
 
        }
 
 
        // Convert to Fahrenheit
 
        if(set.temp_units == TEMP_UNITS_FAHRENHEIT)
 
        {
 
            status.temp = signint * ((temp_pre*100) + status.temp_frac);
 
            status.temp = status.temp * 1.8;
 
            status.temp += 3200;
 
            status.temp_frac = status.temp % 100;
 
            status.temp /= 100;
 
            status.temp += set.temp_offset;
 
        }
 
 
        // Use Celsius values
 
        else
 
        {
 
            status.temp = temp_pre * signint;
 
            status.temp += set.temp_offset;
 
        }
 
    }
 
}
 
 
 
// 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 = set.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 * (status.temp - last_pid_temp));
 
 
  // Save temperature for next iteration
 
  last_pid_temp = status.temp;
 
  last_pid_temp_frac = status.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;
states.h
Show inline comments
 
#ifndef STATES_H
 
#define STATES_H
 

	
 
typedef struct {
 
    int32_t temp;
 
    uint8_t temp_frac;
 
    uint8_t state_resume;
 
    uint8_t state;
 
    int32_t setpoint;
 
    uint8_t pid_enabled;
 
    uint8_t tc_errno;
 
} therm_status_t;
 

	
 
typedef struct {
 
    uint8_t boottobrew;
 
    uint8_t temp_units;
 
    uint16_t windup_guard;
 
    uint16_t k_p;
 
    uint16_t k_i;
 
    uint16_t k_d;
 
    int16_t temp_offset;
 
    uint8_t ignore_tc_error;
 
    int16_t setpoint_brew;
 
    int16_t setpoint_steam;
 
} therm_settings_t;
 

	
 

	
 

	
 
enum tempunits {
 
    TEMP_UNITS_CELSIUS = 0,
 
    TEMP_UNITS_FAHRENHEIT,
 
};
 

	
 
enum state {
 
    STATE_IDLE = 0,
 

	
 
    STATE_SETP,
 
    STATE_SETI,
 
    STATE_SETD,
 
    STATE_SETSTEPS,
 
    STATE_SETWINDUP,
 
    STATE_SETBOOTTOBREW,
 
    STATE_SETUNITS,
 
    STATE_SETTEMPOFFSET,
 

	
 
    STATE_PREHEAT_BREW,
 
    STATE_MAINTAIN_BREW,
 
    STATE_PREHEAT_STEAM,
 
    STATE_MAINTAIN_STEAM,
 

	
 
    STATE_TC_ERROR
 
};
 

	
 
#endif
0 comments (0 inline, 0 general)