#ifndef CONFIG_H
#define CONFIG_H
#define VCP_TX_FREQ 1000
#define SSR_PERIOD 200
#define PID_PERIOD 200
#define LED_POWER GPIOF,GPIO_PIN_0
#define MAX_CS GPIOA,GPIO_PIN_15
#define SW_BTN GPIOB, GPIO_PIN_4
#define SW_UP GPIOB, GPIO_PIN_7
#define SW_DOWN GPIOB, GPIO_PIN_3
#define SW_LEFT GPIOB, GPIO_PIN_5
#define SW_RIGHT GPIOB, GPIO_PIN_6
#define SSR_PIN GPIOA, GPIO_PIN_1
#endif
// vim:softtabstop=4 shiftwidth=4 expandtab
@@ -476,57 +476,64 @@ void display_process(therm_settings_t* s
status->pid_enabled = 1;
status->setpoint = set->setpoint_steam;
// Button handler
if(SW_BTN_PRESSED) {
status->state = STATE_IDLE;
save_setpoints(&set); // 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);
char tempstr[6];
itoa(status->tc_errno, tempstr, 10);
ssd1306_DrawString(tempstr, 0, 57);
if(status->tc_errno == 1)
ssd1306_DrawString(" Check Sensor (1)", 1, 0);
ssd1306_DrawString(" TC Open Circuit", 1, 0);
else if(status->tc_errno == 4)
ssd1306_DrawString(" Check Sensor (2)", 1, 0);
ssd1306_DrawString(" TC Short to GND", 1, 0);
else if(status->tc_errno == 8)
ssd1306_DrawString(" TC Short to VCC", 1, 0);
else
ssd1306_DrawString("#?, Unknown Error", 1, 0);
ssd1306_DrawString(" ", 2, 0);
ssd1306_DrawString("Press -> to ignore", 3, 0);
ssd1306_DrawString("-> to ignore all or", 2, 0);
ssd1306_DrawString("press to continue", 3, 0);
else if(SW_RIGHT_PRESSED) {
set->ignore_tc_error = 1;
// Maybe handle if TC is plugged in
// Something is terribly wrong
default:
status->pid_enabled = 0;
@@ -27,48 +27,49 @@ therm_status_t status;
SPI_HandleTypeDef hspi1;
static __IO uint32_t TimingDelay;
void deinit(void)
HAL_DeInit();
volatile int i=0;
int main(void)
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
/* Configure the system clock */
SystemClock_Config();
/* Unset bootloader option bytes (if set) */
void bootloader_unset(void);
/* Initialize all configured peripherals */
init_gpio();
MX_USB_DEVICE_Init();
// set.usb_plugged =
// USB startup delay
HAL_Delay(1000);
HAL_GPIO_WritePin(LED_POWER, 1);
if(!HAL_GPIO_ReadPin(SW_UP))
bootloader_enter(); // Resets into bootloader
// TODO: Awesome pwm of power LED
// 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();
// Default settings
set.boottobrew = 0;
@@ -143,72 +144,80 @@ void SystemClock_Config(void)
HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit);
__SYSCFG_CLK_ENABLE();
// Grab temperature reading from MAX31855
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) {
/*
if(temp_pre & 0b010) {
HAL_Delay(100); // FIXME: remove?
HAL_Delay(400); // 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) {
} */
if(temp_pre & 0b001 && !set.ignore_tc_error) {
status.tc_errno = 1;
status.state_resume = status.state;
}/*
else if(temp_pre & 0b100 && !set.ignore_tc_error) {
status.tc_errno = 8;
}*/
if(status.state == STATE_TC_ERROR)
status.state = status.state_resume;
//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;
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;
@@ -261,90 +270,100 @@ int16_t update_pid(uint16_t k_p, uint16_
// Calculate differential term (slope since last iteration)
int32_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;
// Return feedback
return result;
uint32_t last_ssr_on = 0;
uint32_t last_vcp_tx = 0;
uint32_t last_led = 0;
uint32_t last_pid = 0;
int16_t ssr_output = 0; // Duty cycle of ssr, 0 to SSR_PERIOD
// Turn SSR output on/off according to set duty cycle.
// TODO: Eventually maybe replace with a very slow timer or something. Double-check this code...
void process()
update_temp(); // Read MAX31855
uint32_t ticks = HAL_GetTick();
if(ticks - last_led > 400)
HAL_GPIO_TogglePin(LED_POWER);
last_led = ticks;
// Every 200ms, set the SSR on unless output is 0
if((ticks - last_ssr_on > SSR_PERIOD))
if((ticks - last_pid > PID_PERIOD))
if(status.pid_enabled)
// Get ssr output for next time
int16_t power_percent = update_pid(set.k_p, set.k_i, set.k_d, status.temp, status.temp_frac, status.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;
ssr_output = 0;
last_pid = ticks;
// Only support heating (ssr_output > 0) right now
if(ssr_output > 0) {
itoa(ssr_output, tempstr, 10);
ssd1306_DrawString(tempstr, 0, 90);
HAL_GPIO_WritePin(SSR_PIN, 1);
last_ssr_on = ticks;
// Kill SSR after elapsed period less than SSR_PERIOD
if(ticks - last_ssr_on > ssr_output || ssr_output == 0)
HAL_GPIO_WritePin(SSR_PIN, 0);
if(ticks - last_vcp_tx > VCP_TX_FREQ)
// Print temp to cdc
char tempstr[16];
itoa_fp(status.temp, status.temp_frac, tempstr);
uint8_t numlen = strlen(tempstr);
tempstr[numlen] = '\r';
tempstr[numlen+1] = '\n';
CDC_Transmit_FS(tempstr, numlen+2);
// if(set.usb_plugged)
// CDC_Transmit_FS(tempstr, numlen+2);
// while(CDC_Transmit_FS("\r\n", 2) == USBD_BUSY);
last_vcp_tx = ticks;
Status change: