@@ -154,419 +154,436 @@ int main(void)
// Run state machine [TODO: 50hz?]
machine();
// probably just passed the actual port
// TODO: Grab buttonpresses with interrupts
//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);
GPIO_SetBits(LED_POWER);
Delay(50);
GPIO_ResetBits(LED_POWER);
}
// 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", 3, 35);
else if(temp_pre & 0b0000000000000001) {
ssd1306_DrawString("TC Fault", 3, 35);
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
GPIO_SetBits(MAX_CS);
int32_t setpoint = 0;
uint16_t k_p = 1;
uint16_t k_i = 1;
uint16_t k_d = 1;
// Process things
void process()
{
update_temp(); // Read MAX31855
// TODO: Add calibration offset (linear)
// Perform PID calculations
//if(
GPIO_SetBits(LED_STAT);
// Write output to SSR
enum state {
STATE_IDLE = 0,
STATE_SETP,
STATE_SETI,
STATE_SETD,
STATE_PREHEAT_BREW,
STATE_MAINTAIN_BREW,
STATE_PREHEAT_STEAM,
STATE_MAINTAIN_STEAM,
};
void draw_setpoint() {
char tempstr[3];
itoa_fp(temp, temp_frac, tempstr);
ssd1306_DrawString(" ", 3, 40);
ssd1306_DrawString(tempstr, 3, 40);
ssd1306_DrawString("-> ", 3, 40);
itoa(setpoint, tempstr);
ssd1306_DrawString(" ", 3, 70);
ssd1306_DrawString(tempstr, 3, 70);
uint8_t state = STATE_IDLE;
uint8_t goto_mode = 2;
// State machine
void machine()
uint8_t last_state = state;
switch(state)
// Idle state
case STATE_IDLE:
// Write text to OLED
// [ therm :: idle ]
ssd1306_DrawString("therm :: idle ", 0, 40);
char tempstr[5];
char tempstr[6];
ssd1306_DrawString("Temp: ", 3, 40);
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);
case 0:
ssd1306_DrawString("-> setup ", 1, 40);
// Button handler
if(!GPIO_ReadInputDataBit(SW_BTN)) {
state = STATE_PREHEAT_BREW;
break;
state = STATE_SETP;
default:
else if(!GPIO_ReadInputDataBit(SW_UP) && goto_mode < 2) {
goto_mode++;
else if(!GPIO_ReadInputDataBit(SW_DOWN) && k_p > 0 && goto_mode > 0) {
goto_mode--;
// Event Handler
// N/A
case STATE_SETP:
// [ therm :: set p ]
// [ p = 12 ]
ssd1306_DrawString("Proportional", 0, 40);
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);
state = STATE_SETI;
else if(!GPIO_ReadInputDataBit(SW_UP)) {
k_p++;
else if(!GPIO_ReadInputDataBit(SW_DOWN) && k_p > 0) {
k_p--;
case STATE_SETI:
// [ therm :: set i ]
// [ i = 12 ]
ssd1306_DrawString("Integral", 0, 40);
itoa(k_i, tempstr);
ssd1306_DrawString("I=", 1, 45);
state = STATE_SETD;
k_i++;
else if(!GPIO_ReadInputDataBit(SW_DOWN) && k_i > 0) {
k_i--;
case STATE_SETD:
// [ therm :: set d ]
// [ d = 12 ]
ssd1306_DrawString("Derivative", 0, 40);
itoa(k_d, tempstr);
ssd1306_DrawString("D=", 1, 45);
state = STATE_IDLE;
k_d++;
else if(!GPIO_ReadInputDataBit(SW_DOWN) && k_d > 0) {
k_d--;
case STATE_PREHEAT_BREW:
// [ therm : preheating brew ]
// [ 30 => 120 C ]
ssd1306_DrawString("Preheating...", 0, 40);
draw_setpoint();
if(temp >= setpoint) {
state = STATE_MAINTAIN_BREW;
case STATE_MAINTAIN_BREW:
// [ therm : ready to brew ]
ssd1306_DrawString("Ready to Brew!", 0, 40);
case STATE_PREHEAT_STEAM:
// [ therm : preheating steam ]
state = STATE_MAINTAIN_STEAM;
case STATE_MAINTAIN_STEAM:
// [ therm : ready to steam ]
ssd1306_DrawString("Ready to Steam!", 0, 40);
// Something is terribly wrong
ssd1306_DrawString("therm :: BAD BAD", 0, 40);
if(last_state != state) {
// Clear screen on state change
ssd1306_block_write();
/**
* @brief Inserts a delay time.
* @param nTime: specifies the delay time length, in 1 ms.
* @retval None
*/
void Delay(__IO uint32_t nTime)
TimingDelay = nTime;
while(TimingDelay != 0);
* @brief Decrements the TimingDelay variable.
* @param None
void TimingDelay_Decrement(void)
if (TimingDelay != 0x00)
TimingDelay--;
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_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_BaudRatePrescaler = SPI_BaudRatePrescaler_8;
SPI_Init(SPI2, &SPI_InitStructure);
SPI_Cmd(SPI2, ENABLE); /* Enable the SPI */
void init_gpio(void) {
GPIO_InitTypeDef GPIO_InitStruct;
// Enable SPI clocks
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1, ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_SPI2, ENABLE);
Status change: