@@ -202,114 +202,128 @@ void update_temp() {
if(sign) {
temp = -temp_pre;
}
else {
temp = temp_pre;
// Deassert CS
Delay(1);
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--;
@@ -373,152 +387,155 @@ void machine()
else if(!GPIO_ReadInputDataBit(SW_DOWN) && k_i > 0) {
k_i--;
// Event Handler
// N/A
case STATE_SETD:
// [ therm :: set d ]
// [ d = 12 ]
ssd1306_DrawString("Derivative", 0, 40);
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);
state = STATE_IDLE;
else if(!GPIO_ReadInputDataBit(SW_UP)) {
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)
Status change: