therm Changeset - 8a3e6f39733b · protofusion repositories

Changeset - 8a3e6f39733b

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Ethan Zonca - 10 years ago 2014-08-26 22:57:39
ez@ethanzonca.com

Initial PID implementation functional

1 file changed with 77 insertions and 6 deletions:

main.c

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main.c

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 #include "main.h"
 #include "stm32l100c_discovery.h"
 #include "ssd1306.h"
 #include "config.h"
 // USB includes
 #include "hw_config.h"
 #include "usb_lib.h"
 #include "usb_desc.h"
 #include "usb_pwr.h"
 #include "stringhelpers.h"
 // TODO: Grab buttonpresses with interrupts
 // TODO: Eliminate screen buffer since we aren't using it...
 // USB Supporting Vars
 extern __IO uint8_t Receive_Buffer[64];
 extern __IO  uint32_t Receive_length ;
 extern __IO  uint32_t length ;
 uint8_t Send_Buffer[64];
 uint32_t packet_sent=1;
 uint32_t packet_receive=1;
 // State definition
 enum state {
     STATE_IDLE = 0,
     STATE_SETP,
     STATE_SETI,
     STATE_SETD,
     STATE_PREHEAT_BREW,
     STATE_MAINTAIN_BREW,
     STATE_PREHEAT_STEAM,
     STATE_MAINTAIN_STEAM,
 };
 static __IO uint32_t TimingDelay;
 // Move to header file
 void init_gpio();
 void init_spi();
 void process();
 void machine();
 void delay(__IO uint32_t nTime);
 int main(void)
+{
     // Init clocks
     SystemInit();
     // Init GPIO
     init_gpio();
     // Init USB
     //Set_USBClock();
     //USB_Interrupts_Config();
     //USB_Init();
     // Turn on power LED
     GPIO_SetBits(LED_POWER);
     // TODO: Awesome pwm of power LED (TIM4_CH4 or TIM11_CH1)
     // TODO: PWM of stat led (TIM3_CH2)
     // Configure 1ms SysTick (change if more temporal resolution needed)
     RCC_ClocksTypeDef RCC_Clocks;
     RCC_GetClocksFreq(&RCC_Clocks);
     SysTick_Config(RCC_Clocks.HCLK_Frequency / 1000);
     // Init SPI busses
     init_spi();
     // Init OLED over SPI
     ssd1306_Init();
     ssd1306_clearscreen();
     // Startup screen
     ssd1306_DrawString("therm v0.1", 1, 40);
     ssd1306_DrawString("protofusion.org/therm", 3, 0);
     delay(1500);
     ssd1306_clearscreen();
     GPIO_ResetBits(LED_STAT);
     // Main loop
     while(1)
+    {
         // Process sensor inputs
         process();
         // Run state machine
         machine();
+    }
+}
 // Read temperature and update global temp vars
 int16_t temp = 0;
 uint8_t temp_frac = 0;
 void update_temp() {
     // Assert CS
     GPIO_ResetBits(MAX_CS);
     delay(1);
     // This may not clock at all... might need to send 16 bits first
     SPI_I2S_SendData(SPI2, 0xAAAA); // send dummy data
     //SPI_I2S_SendData(SPI2, 0xAA); // send dummy data
     uint16_t temp_pre = SPI_I2S_ReceiveData(SPI2);
     if(temp_pre & 0b0000000000000010) {
         ssd1306_DrawString("Fatal Error", 2, 35);
+    }
     else if(temp_pre & 0b0000000000000001) {
         ssd1306_DrawString("Error: No TC", 2, 40);
         temp = 0;
         temp_frac = 0;
+    }
     else
+    {
         uint8_t sign = temp >> 15;// top bit is sign
         temp_pre = temp_pre >> 2; // Drop 2 lowest bits
         temp_frac = temp_pre & 0b11; // get fractional part
         temp_frac *= 25; // each bit is .25 a degree, up to fixed point
         temp_pre = temp_pre >> 2; // Drop 2 fractional bits
         if(sign) {
             temp = -temp_pre;
+        }
         else {
             temp = temp_pre;
+        }
+    }
     // Deassert CS
     delay(1);
     GPIO_SetBits(MAX_CS);
+}
 // PID implementation
 int16_t last_pid_temp = 0;
 uint8_t last_pid_temp_frac = 0;
 int16_t i_state = 0;
 #define WINDUP_GUARD_GAIN 100
 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 = WINDUP_GUARD_GAIN / k_i;
   // Calculate integral term with windup guard
   if (i_state > windup_guard)
     i_state = windup_guard;
   else if (i_state < -windup_guard)
     i_state = -windup_guard;
   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 ticks = 0;
 uint32_t last_ssr_on = 0;
 uint32_t last_led = 0;
 int32_t setpoint = 0;
 uint16_t k_p = 1;
 uint16_t k_i = 1;
 uint16_t k_d = 1;
-uint8_t ssr_output = 0; // Duty cycle of ssr, 0 to SSR_PERIOD
+int16_t ssr_output = 0; // Duty cycle of ssr, 0 to SSR_PERIOD
 // 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) && ssr_output > 0)
     if((ticks - last_ssr_on > SSR_PERIOD))
+    {
         GPIO_SetBits(LED_STAT);
         last_ssr_on = ticks;
         // 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;
         // Only support heating (ssr_output > 0) right now
         if(ssr_output > 0) {
             char tempstr[6];
             itoa(ssr_output, tempstr);
             ssd1306_DrawString("#=", 2, 45);
             ssd1306_DrawString("    ", 2, 57);
             ssd1306_DrawString(tempstr, 2, 57);
             GPIO_SetBits(LED_STAT);
             last_ssr_on = ticks;
+        }
+    }
     // Kill SSR after elapsed period less than SSR_PERIOD
     if(ticks - last_ssr_on > ssr_output)
+    {
         GPIO_ResetBits(LED_STAT);
+    }
+}
 void draw_setpoint() {
     char tempstr[3];
     itoa_fp(temp, temp_frac, tempstr);
     //ssd1306_DrawString("        ", 3, 40);
     ssd1306_DrawString(tempstr, 3, 40);
     ssd1306_DrawString("-> ", 3, 80);
     itoa(setpoint, tempstr);
     ssd1306_DrawString("    ", 3, 95);
     ssd1306_DrawString(tempstr, 3, 95);
+}
 uint8_t state = STATE_IDLE;
 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 machine()
+{
     uint8_t last_state = state;
     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);
             char tempstr[6];
             itoa_fp(temp, temp_frac, tempstr);
             ssd1306_DrawString("Temp: ", 3, 40);
             ssd1306_DrawString("    ", 3, 70);
             ssd1306_DrawString(tempstr, 3, 72);
             ssd1306_drawlogo();
             switch(goto_mode) {
                 case 2:
+                {
                     ssd1306_DrawString("-> brew     ", 1, 40);
                 } break;
                 case 1:
+                {
                     ssd1306_DrawString("-> set P/I/D", 1, 40);
                 } break;
                 case 0:
+                {
                     ssd1306_DrawString("-> setup    ", 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_SETP;
                         break;
                     default:
                         state = STATE_PREHEAT_BREW;
+                }
+            }
             else if(SW_UP_PRESSED && goto_mode < 2) {
                 goto_mode++;
+            }
             else if(SW_DOWN_PRESSED && k_p > 0 && 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 if(!GPIO_ReadInputDataBit(SW_UP)) {
                 k_p++;
+            }
             else if(!GPIO_ReadInputDataBit(SW_DOWN) && k_p > 0) {
                 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 if(!GPIO_ReadInputDataBit(SW_UP)) {
                 k_i++;
+            }
             else if(!GPIO_ReadInputDataBit(SW_DOWN) && k_i > 0) {
                 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_IDLE;
+            }
             else if(!GPIO_ReadInputDataBit(SW_UP)) {
                 k_d++;
+            }
             else if(!GPIO_ReadInputDataBit(SW_DOWN) && k_d > 0) {
                 k_d--;
+            }
             // Event Handler
             // N/A
         } break;
         case STATE_PREHEAT_BREW:
+        {
             // Write text to OLED
             // [ therm : preheating brew ]
             // [ 30 => 120 C             ]
             ssd1306_DrawString("Preheating...", 0, 40);
             ssd1306_drawlogo();
             draw_setpoint();
             // Button handler
             if(SW_BTN_PRESSED) {
                 state = STATE_IDLE;
+            }
             else if(!GPIO_ReadInputDataBit(SW_UP)) {
                setpoint++;
+            }
             else if(!GPIO_ReadInputDataBit(SW_DOWN) && setpoint > 0) {
                 setpoint--;
+            }
             // Event Handler
             if(temp >= setpoint) {
                 state = STATE_MAINTAIN_BREW;
+            }
         } break;
         case STATE_MAINTAIN_BREW:
+        {
             // Write text to OLED
             // [ therm : ready to brew ]
             // [ 30 => 120 C           ]
             ssd1306_DrawString("Ready to Brew!", 0, 40);
             ssd1306_drawlogo();
             draw_setpoint();
             // Button handler
             if(SW_BTN_PRESSED) {
                 state = STATE_IDLE;
+            }
             else if(!GPIO_ReadInputDataBit(SW_UP)) {
                setpoint++;
+            }
             else if(!GPIO_ReadInputDataBit(SW_DOWN) && setpoint > 0) {
                 setpoint--;
+            }
             // Event Handler
             // N/A
         } break;
         case STATE_PREHEAT_STEAM:
+        {
             // Write text to OLED
             // [ therm : preheating steam ]
             // [ 30 => 120 C           ]
             ssd1306_DrawString("Preheating...", 0, 40);
             ssd1306_drawlogo();
             draw_setpoint();
             // Button handler
             if(SW_BTN_PRESSED) {
                 state = STATE_IDLE;
+            }
             else if(!GPIO_ReadInputDataBit(SW_UP)) {
                setpoint++;
+            }
             else if(!GPIO_ReadInputDataBit(SW_DOWN) && setpoint > 0) {
                 setpoint--;
+            }
             // Event Handler
             if(temp >= setpoint) {
                 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, 40);
             ssd1306_drawlogo();
             draw_setpoint();
             // Button handler
             if(SW_BTN_PRESSED) {
                 state = STATE_IDLE;
+            }
             else if(!GPIO_ReadInputDataBit(SW_UP)) {
                setpoint++;
+            }
             else if(!GPIO_ReadInputDataBit(SW_DOWN) && setpoint > 0) {
                 setpoint--;
+            }
             // Event Handler
             // N/A
         } break;
         // Something is terribly wrong
         default:
+        {
             state = STATE_IDLE;
         } break;
+    }
     if(last_state != state) {
         // Clear screen on state change
         ssd1306_clearscreen();
+    }
     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;
+}
 // Delay a number of systicks
 void delay(__IO uint32_t nTime)
+{
   TimingDelay = nTime;
   while(TimingDelay != 0);
+}
 // ISR-triggered decrement of delay and increment of tickcounter
 void TimingDelay_Decrement(void)
+{
   if (TimingDelay != 0x00)
+  {
     TimingDelay--;
+  }
   ticks++;
+}
 void init_spi(void)
+{
     SPI_InitTypeDef  SPI_InitStructure;
     // OLED IC
     SPI_Cmd(SPI1, DISABLE);
     SPI_InitStructure.SPI_Direction = SPI_Direction_1Line_Tx;
     SPI_InitStructure.SPI_Mode = SPI_Mode_Master;
     SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;
     SPI_InitStructure.SPI_CPOL = SPI_CPOL_High;
     SPI_InitStructure.SPI_CPHA = SPI_CPHA_2Edge;
     SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;
     SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_4;
     SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
     SPI_InitStructure.SPI_CRCPolynomial = 7;
     SPI_Init(SPI1, &SPI_InitStructure);
     SPI_Cmd(SPI1, ENABLE);           /* Enable the SPI  */
     // MAX IC
     SPI_Cmd(SPI2, DISABLE);
     SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
     SPI_InitStructure.SPI_Mode = SPI_Mode_Master;
     SPI_InitStructure.SPI_DataSize = SPI_DataSize_16b; // Andysworkshop
     SPI_InitStructure.SPI_CPOL = SPI_CPOL_Low; // From andysworkshop
     SPI_InitStructure.SPI_CPHA = SPI_CPHA_1Edge; // same
     SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;
     SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_8;
     SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
     SPI_InitStructure.SPI_CRCPolynomial = 7;
     SPI_Init(SPI2, &SPI_InitStructure);

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