/** firmware to raise sourdough starter (aka. levain) * @file * @author King Kévin * @copyright SPDX-License-Identifier: GPL-3.0-or-later * @date 2016-2020 */ /* standard libraries */ #include // standard integer types #include // standard utilities #include // string utilities #include // date/time utilities #include // utilities to check chars #include // NaN definition /* STM32 (including CM3) libraries */ #include // Cortex M3 utilities #include // vector table definition #include // interrupt utilities #include // general purpose input output library #include // real-time control clock library #include // external interrupt utilities #include // real time clock utilities #include // independent watchdog utilities #include // debug utilities #include // design utilities #include // flash utilities #include // ADC utilities /* own libraries */ #include "global.h" // board definitions #include "print.h" // printing utilities #include "uart.h" // USART utilities #include "usb_cdcacm.h" // USB CDC ACM utilities #include "terminal.h" // handle the terminal interface #include "menu.h" // menu utilities #include "sensor_sr04.h" // range measurement utilities #include "sensor_ds18b20.h" // 1-Wire temperature sensor utilities #include "oled_text.h" // OLED display utilities /** watchdog period in ms */ #define WATCHDOG_PERIOD 10000 /** wakeup frequency (i.e. least number of times per second to perform the main loop) */ #define WAKEUP_FREQ 16 /** @defgroup main_flags flag set in interrupts to be processed in main task * @{ */ static volatile bool wakeup_flag = false; /**< flag set when wakeup timer triggered */ static volatile bool second_flag = false; /**< flag set when a second passed */ /** @} */ /** number of seconds since boot */ static uint32_t boot_time = 0; // current state static uint32_t levain_time = 0; /**< when we start heating the yeas */ static uint32_t max_time = 0; /**< when the sourdough starter has grown */ static uint16_t current_height = 0; /**< current height */ static uint8_t container_height = 0; /**< how height the container is */ static uint8_t starter_height = 0; /**< how height the sourdough starter starter is */ static uint8_t max_height = 0; /**< the maximum height the sourdough starter reached */ static float heater_temp = NAN; /**< heater temperature */ static float levain_temp = NAN; /**< sourdough starter temperature */ /** heater control pin * @note connected to power nMOS gate, pulled up to 5V */ #define HEATER_PIN PB12 #define heater_on() gpio_set(GPIO_PORT(HEATER_PIN), GPIO_PIN(HEATER_PIN)) // switch transistor on to let resistor heat #define heater_off() gpio_clear(GPIO_PORT(HEATER_PIN), GPIO_PIN(HEATER_PIN)) // switch transistor off /** maximum heater temperature, in °C * @note 50 °C only allowed the starter to go up to 29 °C */ #define HEATER_LIMIT 60.0 /** ADC channel connected to thermistor */ #define THERMISTOR_CHANNEL 6 // PA6 /** voltages to convert (channel 17 = internal voltage reference) */ const uint8_t channels[] = {ADC_CHANNEL17, ADC_CHANNEL(THERMISTOR_CHANNEL)}; /** pin to control buzzer (active high, piezo-element with driver circuit) */ #define BUZZER_PIN PB2 /** temperature to heat the sourdough starter to, in °C */ const float levain_target = 30.0; size_t putc(char c) { size_t length = 0; // number of characters printed static char last_c = 0; // to remember on which character we last sent if ('\n' == c) { // send carriage return (CR) + line feed (LF) newline for each LF if ('\r' != last_c) { // CR has not already been sent uart_putchar_nonblocking('\r'); // send CR over USART usb_cdcacm_putchar('\r'); // send CR over USB length++; // remember we printed 1 character } } uart_putchar_nonblocking(c); // send byte over USART usb_cdcacm_putchar(c); // send byte over USB length++; // remember we printed 1 character last_c = c; // remember last character return length; // return number of characters printed } /** get voltage of thermistor (in V) * @return thermistor voltage */ static double thermistor_voltage(void) { // read thermistor resistance using ADC (using resistor divider) ADC_SR(ADC1) = 0; // reset flags uint16_t adc_values[LENGTH(channels)]; double voltages[LENGTH(channels)]; for (uint8_t i = 0; i < LENGTH(channels); i++) { adc_start_conversion_regular(ADC1); // start conversion (using trigger) while (!adc_eoc(ADC1)); // wait until conversion finished adc_values[i] = adc_read_regular(ADC1); // read voltage value (clears flag) voltages[i] = adc_values[i] * 1.21 / adc_values[0]; // use 1.21 V internal voltage reference to get ADC voltage } return voltages[1]; } /** get temperature of thermistor (in °C) * @return thermistor temperature */ static double thermistor_temperature(void) { // convert to °C // calibrated using a TP101 #define TEMP1 20.5 #define VOLTAGE1 1.813 #define TEMP2 37.9 #define VOLTAGE2 1.197 #define THERMISTOR_SLOPE ((TEMP2 - TEMP1) / (VOLTAGE2 - VOLTAGE1)) #define THERMISTOR_OFFSET (TEMP1 - VOLTAGE1 * THERMISTOR_SLOPE) return thermistor_voltage() * THERMISTOR_SLOPE + THERMISTOR_OFFSET; } // menu commands /** display available commands * @param[in] argument no argument required */ static void command_help(void* argument); /** show software and hardware version * @param[in] argument no argument required */ static void command_version(void* argument) { (void)argument; // we won't use the argument printf("firmware date: %04u-%02u-%02u\n", BUILD_YEAR, BUILD_MONTH, BUILD_DAY); // show firmware build date printf("device serial: %08x%08x%08x\n", DESIG_UNIQUE_ID2, DESIG_UNIQUE_ID1, DESIG_UNIQUE_ID0); // show complete serial (different than the one used for USB) } /** convert RTC date/time to number of seconds * @return number of seconds since 2000-01-01 00:00:00 * @warning for simplicity I consider every month to have 31 days */ static uint32_t rtc_to_seconds(void) { rtc_wait_for_synchro(); // wait until date/time is synchronised const uint8_t year = ((RTC_DR >> RTC_DR_YT_SHIFT) & RTC_DR_YT_MASK) * 10 + ((RTC_DR >> RTC_DR_YU_SHIFT) & RTC_DR_YU_MASK); // get year uint8_t month = ((RTC_DR >> RTC_DR_MT_SHIFT) & RTC_DR_MT_MASK) * 10 + ((RTC_DR >> RTC_DR_MU_SHIFT) & RTC_DR_MU_MASK); // get month if ((RTC_ISR & RTC_ISR_INITS) && month > 0) { // month has been initialized, but starts with 1 month--; // fix for calculation } uint8_t day = ((RTC_DR >> RTC_DR_DT_SHIFT) & RTC_DR_DT_MASK) * 10 + ((RTC_DR >> RTC_DR_DU_SHIFT) & RTC_DR_DU_MASK); // get day if ((RTC_ISR & RTC_ISR_INITS) && day > 0) { // day has been initialized, but starts with 1 day--; // fix for calculation } uint8_t hour = ((RTC_TR >> RTC_TR_HT_SHIFT) & RTC_TR_HT_MASK) * 10 + ((RTC_TR >> RTC_TR_HU_SHIFT) & RTC_TR_HU_MASK); // get hours if (RTC_TR & RTC_TR_PM) { // PM notation is used hour += 12; } const uint8_t minute = ((RTC_TR >> RTC_TR_MNT_SHIFT) & RTC_TR_MNT_MASK) * 10 + ((RTC_TR >> RTC_TR_MNU_SHIFT) & RTC_TR_MNU_MASK); // get minutes const uint8_t second = ((RTC_TR >> RTC_TR_ST_SHIFT) & RTC_TR_ST_MASK) * 10 + ((RTC_TR >> RTC_TR_SU_SHIFT) & RTC_TR_SU_MASK); // get seconds const uint32_t seconds = ((((((((year * 12) + month) * 31) + day) * 24) + hour) * 60) + minute) * 60 + second; // convert to number of seconds return seconds; } /** show uptime * @param[in] argument no argument required */ static void command_uptime(void* argument) { (void)argument; // we won't use the argument const uint32_t uptime = rtc_to_seconds() - boot_time; // get time from internal RTC printf("uptime: %u.%02u:%02u:%02u\n", uptime / (24 * 60 * 60), (uptime / (60 * 60)) % 24, (uptime / 60) % 60, uptime % 60); } /** show date and time * @param[in] argument date and time to set */ static void command_datetime(void* argument) { char* datetime = (char*)argument; // argument is optional date time const char* days[] = { "??", "Mo", "Tu", "We", "Th", "Fr", "Sa", "Su"}; // the days of the week // set date if (datetime) { // date has been provided // parse date const char* malformed = "date and time malformed, expecting YYYY-MM-DD WD HH:MM:SS\n"; if (strlen(datetime) != (4 + 1 + 2 + 1 + 2) + 1 + 2 + 1 + (2 + 1 + 2 + 1 + 2)) { // verify date/time is long enough printf(malformed); return; } if (!(isdigit((int8_t)datetime[0]) && isdigit((int8_t)datetime[1]) && isdigit((int8_t)datetime[2]) && isdigit((int8_t)datetime[3]) && \ '-' == datetime[4] && \ isdigit((int8_t)datetime[5]) && isdigit((int8_t)datetime[6]) && \ '-' == datetime[7] && \ isdigit((int8_t)datetime[8]) && isdigit((int8_t)datetime[9]) && \ ' ' == datetime[10] && \ isalpha((int8_t)datetime[11]) && isalpha((int8_t)datetime[12]) && \ ' ' == datetime[13] && \ isdigit((int8_t)datetime[14]) && isdigit((int8_t)datetime[15]) && \ ':' == datetime[16] && \ isdigit((int8_t)datetime[17]) && isdigit((int8_t)datetime[18]) && \ ':' == datetime[19] && \ isdigit((int8_t)datetime[20]) && isdigit((int8_t)datetime[21]))) { // verify format (good enough to not fail parsing) printf(malformed); return; } const uint16_t year = strtol(&datetime[0], NULL, 10); // parse year if (year <= 2000 || year > 2099) { puts("year out of range\n"); return; } const uint8_t month = strtol(&datetime[5], NULL, 10); // parse month if (month < 1 || month > 12) { puts("month out of range\n"); return; } const uint8_t day = strtol(&datetime[8], NULL, 10); // parse day if (day < 1 || day > 31) { puts("day out of range\n"); return; } const uint8_t hour = strtol(&datetime[14], NULL, 10); // parse hour if (hour > 24) { puts("hour out of range\n"); return; } const uint8_t minute = strtol(&datetime[17], NULL, 10); // parse minutes if (minute > 59) { puts("minute out of range\n"); return; } const uint8_t second = strtol(&datetime[30], NULL, 10); // parse seconds if (second > 59) { puts("second out of range\n"); return; } uint8_t week_day = 0; for (uint8_t i = 1; i < LENGTH(days) && 0 == week_day; i++) { if (days[i][0] == toupper(datetime[11]) && days[i][1] == tolower(datetime[12])) { week_day = i; break; } } if (0 == week_day) { puts("unknown week day\n"); return; } uint32_t date = 0; // to build the date date |= (((year - 2000) / 10) & RTC_DR_YT_MASK) << RTC_DR_YT_SHIFT; // set year tenth date |= (((year - 2000) % 10) & RTC_DR_YU_MASK) << RTC_DR_YU_SHIFT; // set year unit date |= ((month / 10) & RTC_DR_MT_MASK) << RTC_DR_MT_SHIFT; // set month tenth date |= ((month % 10) & RTC_DR_MU_MASK) << RTC_DR_MU_SHIFT; // set month unit date |= ((day / 10) & RTC_DR_DT_MASK) << RTC_DR_DT_SHIFT; // set day tenth date |= ((day % 10) & RTC_DR_DU_MASK) << RTC_DR_DU_SHIFT; // set day unit date |= (week_day & RTC_DR_WDU_MASK) << RTC_DR_WDU_SHIFT; // time day of the week uint32_t time = 0; // to build the time time = 0; // reset time time |= ((hour / 10) & RTC_TR_HT_MASK) << RTC_TR_HT_SHIFT; // set hour tenth time |= ((hour % 10) & RTC_TR_HU_MASK) << RTC_TR_HU_SHIFT; // set hour unit time |= ((minute / 10) & RTC_TR_MNT_MASK) << RTC_TR_MNT_SHIFT; // set minute tenth time |= ((minute % 10) & RTC_TR_MNU_MASK) << RTC_TR_MNU_SHIFT; // set minute unit time |= ((second / 10) & RTC_TR_ST_MASK) << RTC_TR_ST_SHIFT; // set second tenth time |= ((second % 10) & RTC_TR_SU_MASK) << RTC_TR_SU_SHIFT; // set second unit // write date pwr_disable_backup_domain_write_protect(); // disable backup protection so we can set the RTC clock source rtc_unlock(); // enable writing RTC registers RTC_ISR |= RTC_ISR_INIT; // enter initialisation mode while (!(RTC_ISR & RTC_ISR_INITF)); // wait to enter initialisation mode RTC_DR = date; // set date RTC_TR = time; // set time RTC_ISR &= ~RTC_ISR_INIT; // exit initialisation mode rtc_lock(); // protect RTC register against writing pwr_enable_backup_domain_write_protect(); // re-enable protection now that we configured the RTC clock boot_time = rtc_to_seconds() - boot_time; // adjust boot time } // show date if (!(RTC_ISR & RTC_ISR_INITS)) { // date has not been set yet puts("date/time not initialized\n"); } else { rtc_wait_for_synchro(); // wait until date/time is synchronised const uint8_t year = ((RTC_DR >> RTC_DR_YT_SHIFT) & RTC_DR_YT_MASK) * 10 + ((RTC_DR >> RTC_DR_YU_SHIFT) & RTC_DR_YU_MASK); // get year const uint8_t month = ((RTC_DR >> RTC_DR_MT_SHIFT) & RTC_DR_MT_MASK) * 10 + ((RTC_DR >> RTC_DR_MU_SHIFT) & RTC_DR_MU_MASK); // get month const uint8_t day = ((RTC_DR >> RTC_DR_DT_SHIFT) & RTC_DR_DT_MASK) * 10 + ((RTC_DR >> RTC_DR_DU_SHIFT) & RTC_DR_DU_MASK); // get day const uint8_t week_day = ((RTC_DR >> RTC_DR_WDU_SHIFT) & RTC_DR_WDU_MASK); // get week day const uint8_t hour = ((RTC_TR >> RTC_TR_HT_SHIFT) & RTC_TR_HT_MASK) * 10 + ((RTC_TR >> RTC_TR_HU_SHIFT) & RTC_TR_HU_MASK); // get hours const uint8_t minute = ((RTC_TR >> RTC_TR_MNT_SHIFT) & RTC_TR_MNT_MASK) * 10 + ((RTC_TR >> RTC_TR_MNU_SHIFT) & RTC_TR_MNU_MASK); // get minutes const uint8_t second = ((RTC_TR >> RTC_TR_ST_SHIFT) & RTC_TR_ST_MASK) * 10 + ((RTC_TR >> RTC_TR_SU_SHIFT) & RTC_TR_SU_MASK); // get seconds printf("date: 20%02d-%02d-%02d %s %02d:%02d:%02d\n", year, month, day, days[week_day], hour, minute, second); } } /** reset board * @param[in] argument no argument required */ static void command_reset(void* argument) { (void)argument; // we won't use the argument scb_reset_system(); // reset device while (true); // wait for the reset to happen } /** switch to system memory (e.g. embedded bootloader) * @param[in] argument no argument required */ static void command_system(void* argument) { (void)argument; // we won't use the argument system_memory(); // jump to system memory } /** switch to DFU bootloader * @param[in] argument no argument required */ static void command_bootloader(void* argument) { (void)argument; // we won't use the argument dfu_bootloader(); // start DFU bootloader } /** show current state, e.g. all current measurements * @param[in] argument no argument required */ static void command_state(void* argument) { (void)argument; // we won't use the argument puts("sourdough starter statistics:\n"); uint32_t height = ((container_height && starter_height) ? (container_height - starter_height) : 0); printf("initial height: %u mm\n", height); height = ((container_height && current_height) ? (container_height - current_height) : 0); printf("current height: %u mm\n", height); printf("sourdough temperature: %.02f °C\n", levain_temp); printf("heater temperature: %.02f °C\n", heater_temp); puts("heater: "); puts(gpio_get(GPIO_PORT(HEATER_PIN), GPIO_PIN(HEATER_PIN)) ? "on\n" : "off\n"); uint32_t time = (levain_time ? (rtc_to_seconds() - levain_time) : 0); printf("current time: %02u:%02u:%02u\n", time / (60 * 60), (time / 60) % 60, time % 60); height = ((container_height && max_height) ? (container_height - max_height) : 0); printf("maximum height: %u mm\n", height); time = (max_time ? (max_time - levain_time) : 0); printf("maximum height time: %02u:%02u:%02u\n", time / (60 * 60), (time / 60) % 60, time % 60); } /** list of all supported commands */ static const struct menu_command_t menu_commands[] = { { .shortcut = 'h', .name = "help", .command_description = "display help", .argument = MENU_ARGUMENT_NONE, .argument_description = NULL, .command_handler = &command_help, }, { .shortcut = 'v', .name = "version", .command_description = "show software and hardware version", .argument = MENU_ARGUMENT_NONE, .argument_description = NULL, .command_handler = &command_version, }, { .shortcut = 'u', .name = "uptime", .command_description = "show uptime", .argument = MENU_ARGUMENT_NONE, .argument_description = NULL, .command_handler = &command_uptime, }, { .shortcut = 'd', .name = "date", .command_description = "show/set date and time", .argument = MENU_ARGUMENT_STRING, .argument_description = "[YYYY-MM-DD HH:MM:SS]", .command_handler = &command_datetime, }, { .shortcut = 'r', .name = "reset", .command_description = "reset board", .argument = MENU_ARGUMENT_NONE, .argument_description = NULL, .command_handler = &command_reset, }, { .shortcut = 'S', .name = "system", .command_description = "reboot into system memory", .argument = MENU_ARGUMENT_NONE, .argument_description = NULL, .command_handler = &command_system, }, { .shortcut = 'B', .name = "bootloader", .command_description = "reboot into DFU bootloader", .argument = MENU_ARGUMENT_NONE, .argument_description = NULL, .command_handler = &command_bootloader, }, { .shortcut = 's', .name = "state", .command_description = "show state", .argument = MENU_ARGUMENT_NONE, .argument_description = NULL, .command_handler = &command_state, }, }; static void command_help(void* argument) { (void)argument; // we won't use the argument printf("available commands:\n"); menu_print_commands(menu_commands, LENGTH(menu_commands)); // print global commands } /** process user command * @param[in] str user command string (\0 ended) */ static void process_command(char* str) { // ensure actions are available if (NULL == menu_commands || 0 == LENGTH(menu_commands)) { return; } // don't handle empty lines if (!str || 0 == strlen(str)) { return; } bool command_handled = false; if (!command_handled) { command_handled = menu_handle_command(str, menu_commands, LENGTH(menu_commands)); // try if this is not a global command } if (!command_handled) { printf("command not recognized. enter help to list commands\n"); } } /** use buzzer to beep * @param[in] beeps number of times to beep */ static void beep(uint8_t beeps) { for (uint8_t i = 0; i < beeps; i++) { gpio_set(GPIO_PORT(BUZZER_PIN), GPIO_PIN(BUZZER_PIN)); // enable buzzer sleep_ms(100); // buzz to show it is working gpio_clear(GPIO_PORT(BUZZER_PIN), GPIO_PIN(BUZZER_PIN)); // disable buzzer if (i + 1U < beeps) { sleep_ms(100); // buzz to show it is working } } gpio_clear(GPIO_PORT(BUZZER_PIN), GPIO_PIN(BUZZER_PIN)); // ensure buzzer is disabled } /** program entry point * this is the firmware function started by the micro-controller */ void main(void); void main(void) { #if DEBUG // enable functionalities for easier debug DBGMCU_CR |= DBGMCU_CR_IWDG_STOP; // stop independent watchdog counter when code is halted DBGMCU_CR |= DBGMCU_CR_WWDG_STOP; // stop window watchdog counter when code is halted DBGMCU_CR |= DBGMCU_CR_STANDBY; // allow debug also in standby mode (keep digital part and clock powered) DBGMCU_CR |= DBGMCU_CR_STOP; // allow debug also in stop mode (keep clock powered) DBGMCU_CR |= DBGMCU_CR_SLEEP; // allow debug also in sleep mode (keep clock powered) #else // setup watchdog to reset in case we get stuck (i.e. when an error occurred) iwdg_set_period_ms(WATCHDOG_PERIOD); // set independent watchdog period iwdg_start(); // start independent watchdog #endif board_setup(); // setup board uart_setup(); // setup USART (for printing) usb_cdcacm_setup(); // setup USB CDC ACM (for printing) puts("\nwelcome to the CuVoodoo elevainitor sourdough starter raiser\n"); // print welcome message #if DEBUG // show reset cause if (RCC_CSR & (RCC_CSR_LPWRRSTF | RCC_CSR_WWDGRSTF | RCC_CSR_IWDGRSTF | RCC_CSR_SFTRSTF | RCC_CSR_PORRSTF | RCC_CSR_PINRSTF)) { puts("reset cause(s):"); if (RCC_CSR & RCC_CSR_LPWRRSTF) { puts(" low-power"); } if (RCC_CSR & RCC_CSR_WWDGRSTF) { puts(" window-watchdog"); } if (RCC_CSR & RCC_CSR_IWDGRSTF) { puts(" independent-watchdog"); } if (RCC_CSR & RCC_CSR_SFTRSTF) { puts(" software"); } if (RCC_CSR & RCC_CSR_PORRSTF) { puts(" POR/PDR"); } if (RCC_CSR & RCC_CSR_PINRSTF) { puts(" pin"); } putc('\n'); RCC_CSR |= RCC_CSR_RMVF; // clear reset flags } #endif #if !(DEBUG) // show watchdog information printf("setup watchdog: %.2fs", WATCHDOG_PERIOD / 1000.0); if (FLASH_OBR & FLASH_OBR_OPTERR) { puts(" (option bytes not set in flash: software watchdog used, not automatically started at reset)\n"); } else if (FLASH_OBR & FLASH_OBR_WDG_SW) { puts(" (software watchdog used, not automatically started at reset)\n"); } else { puts(" (hardware watchdog used, automatically started at reset)\n"); } #endif // setup RTC puts("setup RTC: "); rcc_periph_clock_enable(RCC_RTC); // enable clock for RTC peripheral if (!(RCC_BDCR && RCC_BDCR_RTCEN)) { // the RTC has not been configured yet pwr_disable_backup_domain_write_protect(); // disable backup protection so we can set the RTC clock source rtc_unlock(); // enable writing RTC registers #if defined(MINIF401) rcc_osc_on(RCC_LSE); // enable LSE clock while (!rcc_is_osc_ready(RCC_LSE)); // wait until clock is ready rtc_set_prescaler(256, 128); // set clock prescaler to 32768 RCC_BDCR = (RCC_BDCR & ~(RCC_BDCR_RTCSEL_MASK << RCC_BDCR_RTCSEL_SHIFT)) | (RCC_BDCR_RTCSEL_LSE << RCC_BDCR_RTCSEL_SHIFT); // select LSE as RTC clock source #else rcc_osc_on(RCC_LSI); // enable LSI clock while (!rcc_is_osc_ready(RCC_LSI)); // wait until clock is ready rtc_set_prescaler(250, 128); // set clock prescaler to 32000 RCC_BDCR = (RCC_BDCR & ~(RCC_BDCR_RTCSEL_MASK << RCC_BDCR_RTCSEL_SHIFT)) | (RCC_BDCR_RTCSEL_LSI << RCC_BDCR_RTCSEL_SHIFT); // select LSI as RTC clock source #endif RCC_BDCR |= RCC_BDCR_RTCEN; // enable RTC rtc_lock(); // protect RTC register against writing pwr_enable_backup_domain_write_protect(); // re-enable protection now that we configured the RTC clock } boot_time = rtc_to_seconds(); // remember the start time puts("OK\n"); // setup wakeup timer for periodic checks puts("setup wakeup: "); // RTC needs to be configured beforehand pwr_disable_backup_domain_write_protect(); // disable backup protection so we can write to the RTC registers rtc_unlock(); // enable writing RTC registers rtc_clear_wakeup_flag(); // clear flag for fresh start #if defined(MINIF401) rtc_set_wakeup_time((32768 / 2) / WAKEUP_FREQ - 1, RTC_CR_WUCLKSEL_RTC_DIV2); // set wakeup time based on LSE (keep highest precision, also enables the wakeup timer) #else rtc_set_wakeup_time((32000 / 2) / WAKEUP_FREQ - 1, RTC_CR_WUCLKSEL_RTC_DIV2); // set wakeup time based on LSI (keep highest precision, also enables the wakeup timer) #endif rtc_enable_wakeup_timer_interrupt(); // enable interrupt rtc_lock(); // disable writing RTC registers // important: do not re-enable backup_domain_write_protect, since this will prevent clearing flags (but RTC registers do not need to be unlocked) puts("OK\n"); puts("setup heater: "); rcc_periph_clock_enable(GPIO_RCC(HEATER_PIN)); // enable clock for GPIO port domain gpio_mode_setup(GPIO_PORT(HEATER_PIN), GPIO_MODE_INPUT, GPIO_PUPD_NONE, GPIO_PIN(HEATER_PIN)); // set GPIO to input floating const bool heater_ok = gpio_get(GPIO_PORT(HEATER_PIN), GPIO_PIN(HEATER_PIN)); // pin should be put high gpio_mode_setup(GPIO_PORT(HEATER_PIN), GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, GPIO_PIN(HEATER_PIN)); // set pin as output gpio_set_output_options(GPIO_PORT(HEATER_PIN), GPIO_OTYPE_OD, GPIO_OSPEED_2MHZ, GPIO_PIN(HEATER_PIN)); // set pin output as open-drain heater_off(); // set heater off if (heater_ok) { puts("OK\n"); } else { puts("KO\n"); } puts("setup HC-SR04 range sensor: "); sensor_sr04_setup(); // setup peripheral sensor_sr04_distance = 0; // clear flag sensor_sr04_trigger(); // start measurement while(!sensor_sr04_distance); // wait for measurement to complete const bool sensor_sr04_ok = (1 != sensor_sr04_distance); // if no echo received, the module is not present sensor_sr04_distance = 0; // clear flag if (sensor_sr04_ok) { puts("OK\n"); } else { puts("KO\n"); } puts("setup DS18B20 temperature sensor: "); sensor_ds18b20_setup(); // setup peripheral const bool sensor_ds18b20_present = (1 == sensor_ds18b20_number() && sensor_ds18b20_only()); // ensure there is only one ds18b20 sensor on the bus (so we don't have to use its ROM code) if (sensor_ds18b20_present) { sensor_ds18b20_precision(0, 12); // use highest resolution. it requires 750 ms to do the conversion, but we only check once a second sensor_ds18b20_convert(0); // start the conversion puts("OK\n"); } else { puts("KO\n"); } puts("setup ADC for thermistor: "); rcc_periph_clock_enable(RCC_ADC1); // enable clock for ADC domain adc_power_off(ADC1); // switch off ADC while configuring it adc_set_right_aligned(ADC1); // ensure it is right aligned to get the actual value in the 16-bit register adc_enable_scan_mode(ADC1); // use scan mode do be able to go to next discontinuous subgroup of the regular sequence adc_enable_discontinuous_mode_regular(ADC1, 1); // use discontinuous mode (to go through all channels of the group, one after another) adc_set_single_conversion_mode(ADC1); // ensure continuous mode is not used (that's not the same as discontinuous) adc_eoc_after_each(ADC1); // set EOC after each conversion instead of each group adc_set_sample_time_on_all_channels(ADC1, ADC_SMPR_SMP_28CYC); // use at least 15 cycles to be able to sample at 12-bit resolution adc_set_regular_sequence(ADC1, LENGTH(channels), (uint8_t*)channels); // set channel to convert adc_enable_temperature_sensor(); // enable internal voltage reference adc_power_on(ADC1); // switch on ADC sleep_us(3); // wait t_stab for the ADC to stabilize rcc_periph_clock_enable(RCC_ADC1_IN(THERMISTOR_CHANNEL)); // enable clock for GPIO domain for thermistor channel gpio_mode_setup(ADC1_IN_PORT(THERMISTOR_CHANNEL), GPIO_MODE_ANALOG, GPIO_PUPD_NONE, ADC1_IN_PIN(THERMISTOR_CHANNEL)); // set thermistor channel as analog input for the ADC const bool thermsitor_ok = (thermistor_voltage() > 1.0 && thermistor_voltage() < 2.0); // ensure thermistor is connected if (thermsitor_ok) { puts("OK\n"); } else { puts("KO\n"); } puts("setup SSD1306 OLED display: "); const bool oled_text_ok = oled_text_setup(); // setup display if (oled_text_ok) { oled_text_clear(); oled_text_line("ELEVAINITOR", 0); oled_text_update(); puts("OK\n"); } else { puts("KO\n"); } // show status const bool all_ok = heater_ok && sensor_sr04_ok && sensor_ds18b20_present && thermsitor_ok && oled_text_ok; if (oled_text_ok) { if (all_ok) { oled_text_line("press button", 1); oled_text_line("no sourdough", 2); oled_text_update(); } else { oled_text_line("error", 1); if (!heater_ok) { oled_text_line("heater", 2); } else if (!sensor_sr04_ok) { oled_text_line("heater MOSFET", 2); } else if (!sensor_ds18b20_present) { oled_text_line("heater thermo.", 2); } else if (!thermsitor_ok) { oled_text_line("thermistor", 2); } else { oled_text_line("unknown", 2); } oled_text_update(); } } puts("setup buzzer: "); rcc_periph_clock_enable(GPIO_RCC(BUZZER_PIN)); // enable clock for GPIO port domain gpio_clear(GPIO_PORT(BUZZER_PIN), GPIO_PIN(BUZZER_PIN)); // disable buzzer gpio_mode_setup(GPIO_PORT(BUZZER_PIN), GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, GPIO_PIN(BUZZER_PIN)); // set pin as output gpio_set_output_options(GPIO_PORT(BUZZER_PIN), GPIO_OTYPE_PP, GPIO_OSPEED_2MHZ, GPIO_PIN(BUZZER_PIN)); // set pin output as push-pull beep(1); // buzz to show it is working puts("OK\n"); // setup terminal terminal_prefix = ""; // set default prefix terminal_process = &process_command; // set central function to process commands terminal_setup(); // start terminal // start main loop bool action = false; // if an action has been performed don't go to sleep button_flag = false; // reset button flag led_on(); // switch LED to indicate booting completed uint32_t peak_time = 0; // when the sourdough starter has reached its peak while (true) { // infinite loop iwdg_reset(); // kick the dog if (user_input_available) { // user input is available action = true; // action has been performed led_toggle(); // toggle LED char c = user_input_get(); // store receive character terminal_send(c); // send received character to terminal } if (button_flag) { // user pressed button action = true; // action has been performed puts("button pressed\n"); led_toggle(); // toggle LED if (!all_ok) { puts("can only start when all peripherals are ok\n"); puts("restart to check again\n"); } else if (0 == container_height) { // time to get container height puts("container height: "); sleep_ms(2000); // wait for used to remove his finger from the lid sensor_sr04_distance = 0; // clear measurement sensor_sr04_trigger(); // start measurement while (!sensor_sr04_distance); // wait for distance measurement if (1 == sensor_sr04_distance) { puts("range sensor not available\n"); break; } else if (sensor_sr04_distance > 255) { puts("probably not on container\n"); break; } else { // valid height container_height = sensor_sr04_distance; // remember height printf("%u mm\n", container_height); // display measurement oled_text_line("with starter", 2); // display next instruction oled_text_update(); // show instruction beep(1); // beep to indicate action completed } sensor_sr04_distance = 0; // clear measurement } else if (0 == levain_time || 0 == starter_height) { // time to start monitoring puts("starter height: "); sleep_ms(2000); // wait for used to remove his finger from the lid sensor_sr04_distance = 0; // clear measurement sensor_sr04_trigger(); // start measurement while (!sensor_sr04_distance); // wait for distance measurement if (1 == sensor_sr04_distance) { puts("range sensor not available\n"); break; } else if (sensor_sr04_distance >= container_height) { puts("probably no starter\n"); break; } else { // valid height starter_height = sensor_sr04_distance; // remember height max_height = starter_height; // initialize the maximum height levain_time = rtc_to_seconds(); // remember when we start monitoring max_time = levain_time; // initialize the maximum height time printf("%u mm\n", starter_height); // display measurement beep(1); // beep to indicate action completed } sensor_sr04_distance = 0; // clear measurement } sleep_ms(100); // wait a bit to remove noise and double trigger button_flag = false; // reset flag } if (wakeup_flag) { // time to do periodic checks wakeup_flag = false; // clear flag } if (second_flag) { // one second passed second_flag = false; // clear flag action = true; // action will be performed led_toggle(); // toggle LED to indicate if main function is stuck // get heater temperature if (sensor_ds18b20_present) { heater_temp = sensor_ds18b20_temperature(0); // get temperature if (85.0 != heater_temp) { // the conversion has not been completed sensor_ds18b20_convert(0); // start next conversion } } // get sourdough starter temperature if (thermsitor_ok) { levain_temp = thermistor_temperature(); // get temperature } // update uptime if (levain_time) { const uint32_t uptime = rtc_to_seconds() - levain_time; // get time from internal RTC char strtime[12]; // to store time representation snprintf(strtime, sizeof(strtime), "%u.%02u:%02u:%02u", uptime / (24 * 60 * 60), (uptime / (60 * 60)) % 24, (uptime / 60) % 60, uptime % 60); // get uptime representation oled_text_line(strtime, 1); // add text to display buffer } // get height if (sensor_sr04_ok) { // sensor working sensor_sr04_trigger(); // start measurement } // heat up sourdough starter if (levain_time && !isnan(levain_temp) && heater_ok && !isnan(heater_temp)) { if (levain_temp < levain_target - 0.5 && 0 == peak_time) { // temperature not reached heater_on(); // keep heating } else if (levain_temp > levain_target + 0.5) { // temperature reached heater_off(); // stop heating } } // turn off heater for safety if (!isnan(heater_temp) && heater_temp > HEATER_LIMIT) { heater_off(); // stop heating } // update how much the starter raised if (current_height && container_height && starter_height && max_height && current_height <= starter_height) { const float rising = (container_height - current_height) * 1.0 / (container_height - starter_height); // calculate ratio char text[13]; // to store text representation snprintf(text, sizeof(text), "%.02fx %.01fC", rising, levain_temp); // display ratio and temperature oled_text_line(text, 2); // add text to display buffer if (current_height < max_height && (current_height + 5U) > max_height) { // a new maximum height has been reached (and is credible) max_height = current_height; // save new maximum height max_time = rtc_to_seconds(); // remember the time } if (current_height > max_height + 5) { // the sourdough starter has been falling again if (max_time > peak_time) { heater_off(); // stop heating peak_time = max_time; // remember the peak sourdough starter time const float peak_ratio = (container_height - max_height) * 1.0 / (container_height - starter_height); // calculate ratio const uint16_t peak_period = peak_time - levain_time; // calculate peak time snprintf(text, sizeof(text), "%.02fx %um", peak_ratio, peak_period / 60); // display peak ratio and time oled_text_line(text, 3); // add text to display buffer beep(2); // beep to indicate the peak has been reached } } } // display new data (even if nothing new) if (oled_text_ok) { oled_text_update(); // display buffered data } } if (sensor_sr04_distance) { // distance measurement is available //printf("height: %u mm\n", sensor_sr04_distance); current_height = sensor_sr04_distance; // save height sensor_sr04_distance = 0; // clear flag } if (action) { // go to sleep if nothing had to be done, else recheck for activity action = false; } else { __WFI(); // go to sleep } } // main loop } /** interrupt service routine when the wakeup timer triggered */ void rtc_wkup_isr(void) { static uint16_t tick = WAKEUP_FREQ; // how many wakeup have occurred exti_reset_request(EXTI22); // clear EXTI flag used by wakeup rtc_clear_wakeup_flag(); // clear flag wakeup_flag = true; // notify main loop tick--; // count the number of ticks down (do it in the ISR to no miss any tick) if (0 == tick) { // count down completed second_flag = true; // notify main loop a second has passed tick = WAKEUP_FREQ; // restart count down } }