RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE); // EMZ TODO get the right ones

  /*Configure GPIO pin : PC */

  GPIO_InitStruct.GPIO_Pin = GPIO_Pin_13;

  GPIO_InitStruct.GPIO_Mode = GPIO_Mode_OUT;

  GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;

  GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;

  GPIO_InitStruct.GPIO_Speed = GPIO_Speed_400KHz;

  GPIO_Init(GPIOC, &GPIO_InitStruct);

  /*Configure GPIO pin : PB */

  GPIO_InitStruct.GPIO_Pin = GPIO_Pin_1|GPIO_Pin_2|GPIO_Pin_10|GPIO_Pin_12 

                          |GPIO_Pin_9;

  GPIO_InitStruct.GPIO_Mode = GPIO_Mode_OUT;

  GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;

  GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;

  GPIO_InitStruct.GPIO_Speed = GPIO_Speed_400KHz;

  GPIO_Init(GPIOB, &GPIO_InitStruct);

  /*Configure GPIO pin : PA */

  GPIO_InitStruct.GPIO_Pin = GPIO_Pin_15;

  GPIO_InitStruct.GPIO_Mode = GPIO_Mode_OUT;

  GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;

  GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;

  GPIO_InitStruct.GPIO_Speed = GPIO_Speed_400KHz;

  GPIO_Init(GPIOA, &GPIO_InitStruct);

  /*Configure GPIO pin : PB */

  GPIO_InitStruct.GPIO_Pin = GPIO_Pin_3|GPIO_Pin_4|GPIO_Pin_5|GPIO_Pin_6 

                          |GPIO_Pin_7;

  GPIO_InitStruct.GPIO_Mode = GPIO_Mode_IN;

  GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_UP;

  GPIO_Init(GPIOB, &GPIO_InitStruct);

  /** SPI1 GPIO Configuration  

  PA5   ------> SPI1_SCK

  PA7   ------> SPI1_MOSI

  */

  /*Enable or disable the AHB peripheral clock */

  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);

  /*Configure GPIO pin : PA: MOSI,SCK */

  GPIO_InitStruct.GPIO_Pin = GPIO_Pin_5|GPIO_Pin_7;

  GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF;

  GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;

  GPIO_InitStruct.GPIO_Speed = GPIO_Speed_10MHz;

  GPIO_Init(GPIOA, &GPIO_InitStruct);

  /*Configure GPIO pin alternate function */

  GPIO_PinAFConfig(GPIOA, GPIO_PinSource5, GPIO_AF_SPI1);

  /*Configure GPIO pin alternate function */

  GPIO_PinAFConfig(GPIOA, GPIO_PinSource7, GPIO_AF_SPI1);

  /** SPI2 GPIO Configuration  

  PB13   ------> SPI2_SCK

  PB14   ------> SPI2_MISO

  PB15   ------> SPI2_MOSI

  */

  /*Enable or disable the AHB peripheral clock */

  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOB, ENABLE);

// SPI PINSSS

  /*Configure GPIO pin : PB, MOSI, SCK */

  GPIO_InitStruct.GPIO_Pin = GPIO_Pin_13|GPIO_Pin_15;

  GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF;

  GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;

  GPIO_InitStruct.GPIO_Speed = GPIO_Speed_10MHz;

  GPIO_Init(GPIOB, &GPIO_InitStruct);

 GPIO_InitTypeDef GPIO_InitStruct2;

// MISO

  GPIO_InitStruct2.GPIO_Pin = GPIO_Pin_14;

  GPIO_InitStruct2.GPIO_Mode = GPIO_Mode_AF;

  GPIO_InitStruct2.GPIO_PuPd = GPIO_PuPd_NOPULL;

  GPIO_InitStruct2.GPIO_Speed = GPIO_Speed_10MHz;

  GPIO_Init(GPIOB, &GPIO_InitStruct2);

  //Configure GPIO pin alternate function 

  GPIO_PinAFConfig(GPIOB, GPIO_PinSource13, GPIO_AF_SPI2);

  GPIO_PinAFConfig(GPIOB, GPIO_PinSource14, GPIO_AF_SPI2);

  GPIO_PinAFConfig(GPIOB, GPIO_PinSource15, GPIO_AF_SPI2);

  /** USB GPIO Configuration  

  PA11   ------> USB_DM

  PA12   ------> USB_DP

  */

  /*Enable or disable the AHB peripheral clock */

  RCC_AHBPeriphClockCmd(RCC_AHBPeriph_GPIOA, ENABLE);

  /*Configure GPIO pin : PA */

}

// vim:softtabstop=4 shiftwidth=4 expandtab 

#include "ssd1306.h"

#include "config.h"

#include "eeprom_min.h"

#include "gpio.h"

#include "spi.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

// 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;

// Globalish setting vars

uint8_t boottobrew = 0;

uint16_t windup_guard = 1;

uint16_t k_p = 1;

uint16_t k_i = 1;

uint16_t k_d = 1;

// ISR ticks var

volatile uint32_t ticks = 0;

int16_t setpoint_brew = 0;

int16_t setpoint_steam = 0;

// State definition

enum state {

    STATE_IDLE = 0,

    STATE_SETP,

    STATE_SETI,

    STATE_SETD,

    STATE_SETWINDUP,

    STATE_SETBOOTTOBREW,

    STATE_PREHEAT_BREW,

    STATE_MAINTAIN_BREW,

    STATE_PREHEAT_STEAM,

    STATE_MAINTAIN_STEAM,

};

uint8_t state = STATE_IDLE;

static __IO uint32_t TimingDelay;

// Move to header file

void process();

void machine();

void restore_settings();

void save_settings();

void save_setpoints();

int main(void)

{

    // Init clocks

    SystemInit();

    // Init GPIO

    init_gpio();

    // Turn on power LED

    GPIO_SetBits(LED_POWER);

    // TODO: Awesome pwm of power LED (TIM4_CH4 or TIM11_CH1)

    // 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();

    // Check for problems on startup

    if(clock_fail) {

        ssd1306_DrawString("ERROR: Check Xtal", 3, 0);

        delay(2000);

    }

    // Init USB

    // Startup screen 

    ssd1306_DrawString("therm v0.1", 1, 40);

    ssd1306_DrawString("protofusion.org/therm", 3, 0);

    delay(1500);

    ssd1306_clearscreen();

    restore_settings();

    if(boottobrew)

      state = STATE_PREHEAT_BREW; // Go to brew instead of idle if configured thusly

    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

// 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