/* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see .
*
*/
/** sound level enforcer
* @file
* @author King Kévin
* @date 2016-2020
*/
/* standard libraries */
#include // standard integer types
#include // standard utilities
#include // string utilities
#include // date/time utilities
#include // utilities to check char
#include // for rounding floats
/* 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
/* own libraries */
#include "global.h" // board definitions
#include "print.h" // printing utilities
#if !defined(STLINKV2)
#include "uart.h" // USART utilities
#endif
#include "usb_cdcacm.h" // USB CDC ACM utilities
#include "terminal.h" // handle the terminal interface
#include "menu.h" // menu utilities
#include "led_tm1637.h" // 7-segment display
#include "spp_rx.h" // Bluetooth SPP input
#include "flash_internal.h" // settings storage
/** watchdog period in ms */
#define WATCHDOG_PERIOD 10000
/** set to 0 if the RTC is reset when the board is powered on, only indicates the uptime
* set to 1 if VBAT can keep the RTC running when the board is unpowered, indicating the date and time
*/
#if defined(CORE_BOARD)
#define RTC_DATE_TIME 1
#else
#define RTC_DATE_TIME 0
#endif
/** number of RTC ticks per second
* @note use integer divider of oscillator to keep second precision
*/
#define RTC_TICKS_SECOND 4
/** RTC time when device is started */
static time_t time_start = 0;
/** @defgroup main_flags flag set in interrupts to be processed in main task
* @{
*/
volatile bool rtc_internal_tick_flag = false; /**< flag set when internal RTC ticked */
/** @} */
/** buffer for the data received over Bluetooth from the sound level meter */
static char spp_input_buffer[16];
/** how much received data is buffered */
static uint8_t spp_input_i = 0;
/** pin to control relay (active low) */
#define RELAY_PIN PB15
/** default sound level threshold (in dBa) */
#define SOUND_LEVEL_THRESHOLD 100
/** configured sound level threshold (in dBa) */
static uint8_t sound_level_threshold = SOUND_LEVEL_THRESHOLD;
/** default sound level duration (in seconds) */
#define SOND_LEVEL_DURATION 10
/** configured sound level duration (in seconds) */
static uint8_t sound_level_duration = SOND_LEVEL_DURATION;
/** if we show the received sound level value */
static bool sound_level_show = false;
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
#if !defined(STLINKV2)
uart_putchar_nonblocking('\r'); // send CR over USART
#endif
usb_cdcacm_putchar('\r'); // send CR over USB
length++; // remember we printed 1 character
}
}
#if !defined(STLINKV2)
uart_putchar_nonblocking(c); // send byte over USART
#endif
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
}
/** 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);
/** show uptime
* @param[in] argument no argument required
*/
static void command_uptime(void* argument);
#if RTC_DATE_TIME
/** show date and time
* @param[in] argument date and time to set
*/
static void command_datetime(void* argument);
#endif
/** reset board
* @param[in] argument no argument required
*/
static void command_reset(void* argument);
/** switch to DFU bootloader
* @param[in] argument no argument required
*/
static void command_bootloader(void* argument);
/** load sound level threshold and duration settings from flash
* @return if values are loaded from flash (else set to default)
*/
static bool sound_level_load(void)
{
uint8_t eeprom_data[4] = {0};
const bool eeprom_read = flash_internal_eeprom_read(eeprom_data, sizeof(eeprom_data));
if (eeprom_read) {
eeprom_data[1] ^= 0xff; // xor value (sort of checksum)
eeprom_data[3] ^= 0xff; // xor value (sort of checksum)
if (eeprom_data[0] == eeprom_data[1] && eeprom_data[2] == eeprom_data[3]) {
sound_level_threshold = eeprom_data[0];
sound_level_duration = eeprom_data[2];
return true;
} else {
return false;
}
} else {
sound_level_threshold = SOUND_LEVEL_THRESHOLD;
sound_level_duration = SOND_LEVEL_DURATION;
return false;
}
}
/** save sound level threshold and duration settings into flash
* @return if succeeded
*/
static bool sound_level_save(void)
{
const uint8_t eeprom_data[4] = {
sound_level_threshold,
sound_level_threshold ^ 0xff,
sound_level_duration,
sound_level_duration ^ 0xff,
};
const int32_t rc = flash_internal_eeprom_write(eeprom_data, sizeof(eeprom_data));
if (rc < 0) {
printf("error saving sound level data: %d\n", rc);
}
return rc == sizeof(eeprom_data);
}
/** set sound level threshold
* @param[in] argument sound level threshold
*/
static void command_sound_level_threshold(void* argument)
{
if (argument) { // tachometer value has been provided
const uint32_t value = *(uint32_t*)argument; // get target sound level threshold value
sound_level_threshold = value;
if (!sound_level_save()) {
puts("could not save sound level threshold\n");
}
}
printf("sound level threshold set to %u dBa\n", sound_level_threshold);
}
/** set sound level duration
* @param[in] argument sound level duration
*/
static void command_sound_level_duration(void* argument)
{
if (argument) { // tachometer value has been provided
const uint32_t value = *(uint32_t*)argument; // get target sound level duration value
sound_level_duration = value;
if (!sound_level_save()) {
puts("could not save sound level duration\n");
}
}
printf("sound level duration set to %u s\n", sound_level_duration);
}
/** show/hide received sound level
* @param[in] argument not used
*/
static void command_show(void* argument)
{
(void)argument; // we won't use the argument
sound_level_show = !sound_level_show; // toggle setting
puts(sound_level_show ? "show" : "hide");
puts(" received sound level\n");
}
/** 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,
},
#if RTC_DATE_TIME
{
.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,
},
#endif
{
.shortcut = 'r',
.name = "reset",
.command_description = "reset board",
.argument = MENU_ARGUMENT_NONE,
.argument_description = NULL,
.command_handler = &command_reset,
},
{
.shortcut = 'b',
.name = "bootloader",
.command_description = "reboot into DFU bootloader",
.argument = MENU_ARGUMENT_NONE,
.argument_description = NULL,
.command_handler = &command_bootloader,
},
{
.shortcut = 't',
.name = "threshold",
.command_description = "get/set sound level threshold (in dBa)",
.argument = MENU_ARGUMENT_UNSIGNED,
.argument_description = "[value]",
.command_handler = &command_sound_level_threshold,
},
{
.shortcut = 'd',
.name = "duration",
.command_description = "get/set sound level duration (in seconds)",
.argument = MENU_ARGUMENT_UNSIGNED,
.argument_description = "[value]",
.command_handler = &command_sound_level_duration,
},
{
.shortcut = 's',
.name = "show",
.command_description = "show/hide received sound level",
.argument = MENU_ARGUMENT_NONE,
.argument_description = NULL,
.command_handler = &command_show,
},
};
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
}
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
// get device identifier (DEV_ID)
// 0x412: low-density, 16-32 kB flash
// 0x410: medium-density, 64-128 kB flash
// 0x414: high-density, 256-512 kB flash
// 0x430: XL-density, 768-1024 kB flash
// 0x418: connectivity
printf("device family: ");
switch (DBGMCU_IDCODE & DBGMCU_IDCODE_DEV_ID_MASK) {
case 0: // this is a known issue document in STM32F10xxC/D/E Errata sheet, without workaround
printf("unreadable\n");
break;
case 0x412:
printf("low-density\n");
break;
case 0x410:
printf("medium-density\n");
break;
case 0x414:
printf("high-density\n");
break;
case 0x430:
printf("XL-density\n");
break;
case 0x418:
printf("connectivity\n");
break;
default:
printf("unknown\n");
break;
}
// show flash size
printf("flash size: ");
if (0xffff == DESIG_FLASH_SIZE) {
printf("unknown (probably a defective micro-controller\n");
} else {
printf("%u KB\n", DESIG_FLASH_SIZE);
}
// display device identity
printf("device id: %08x%08x%08x\n", DESIG_UNIQUE_ID0, DESIG_UNIQUE_ID1, DESIG_UNIQUE_ID2);
}
static void command_uptime(void* argument)
{
(void)argument; // we won't use the argument
uint32_t uptime = (rtc_get_counter_val() - time_start) / RTC_TICKS_SECOND; // 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);
}
#if RTC_DATE_TIME
static void command_datetime(void* argument)
{
char* datetime = (char*)argument; // argument is optional date time
if (NULL == argument) { // no date and time provided, just show the current day and time
time_t time_rtc = rtc_get_counter_val() / RTC_TICKS_SECOND; // get time from internal RTC
struct tm* time_tm = localtime(&time_rtc); // convert time
printf("date: %d-%02d-%02d %02d:%02d:%02d\n", 1900 + time_tm->tm_year, time_tm->tm_mon, time_tm->tm_mday, time_tm->tm_hour, time_tm->tm_min, time_tm->tm_sec);
} else { // date and time provided, set it
const char* malformed = "date and time malformed, expecting YYYY-MM-DD HH:MM:SS\n";
struct tm time_tm; // to store the parsed date time
if (strlen(datetime) != (4 + 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] && isdigit((int8_t)datetime[11]) && isdigit((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]))) { // verify format (good enough to not fail parsing)
printf(malformed);
return;
}
time_tm.tm_year = strtol(&datetime[0], NULL, 10) - 1900; // parse year
time_tm.tm_mon = strtol(&datetime[5], NULL, 10); // parse month
time_tm.tm_mday = strtol(&datetime[8], NULL, 10); // parse day
time_tm.tm_hour = strtol(&datetime[11], NULL, 10); // parse hour
time_tm.tm_min = strtol(&datetime[14], NULL, 10); // parse minutes
time_tm.tm_sec = strtol(&datetime[17], NULL, 10); // parse seconds
time_t time_rtc = mktime(&time_tm); // get back seconds
time_start = time_rtc * RTC_TICKS_SECOND + (rtc_get_counter_val() - time_start); // update uptime with current date
rtc_set_counter_val(time_rtc * RTC_TICKS_SECOND); // save date/time to internal RTC
printf("date and time saved: %d-%02d-%02d %02d:%02d:%02d\n", 1900 + time_tm.tm_year, time_tm.tm_mon, time_tm.tm_mday, time_tm.tm_hour, time_tm.tm_min, time_tm.tm_sec);
}
}
#endif
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
}
static void command_bootloader(void* argument)
{
(void)argument; // we won't use the argument
// set DFU magic to specific RAM location
__dfu_magic[0] = 'D';
__dfu_magic[1] = 'F';
__dfu_magic[2] = 'U';
__dfu_magic[3] = '!';
scb_reset_system(); // reset system (core and peripherals)
while (true); // wait for the reset to happen
}
/** 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");
}
}
/** parse and display sound level value
* @param[io] str line with dBA measurement
* @return parsed measurement (0 if failed)
* @warning modifies str
*/
static uint8_t parse_measurement(char* str)
{
if (strlen(str) < 5) { // minimum size for a valid message
return 0;
}
const char* delimiter = " "; // words are separated by spaces
const char* value_s = strtok(str, delimiter); // get measurement value
if (!value_s) {
return 0;
}
const char* unit = strtok(NULL, delimiter); // get measurement unit
if (!unit) {
return 0;
}
if (strncmp("dBa", unit, 3)) { // the measurement unit is the right one
return 0;
}
const double value_f = atof(value_s); // get measurement value
if (isnan(value_f) || value_f < 0.1) {
return 0;
}
const uint8_t value_i = round(value_f); // get rounded measurement value
return value_i;
}
/** program entry point
* this is the firmware function started by the micro-controller
*/
void main(void);
void main(void)
{
rcc_clock_setup_in_hse_8mhz_out_72mhz(); // use 8 MHz high speed external clock to generate 72 MHz internal clock
#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
#if !defined(STLINKV2)
uart_setup(); // setup USART (for printing)
#endif
usb_cdcacm_setup(); // setup USB CDC ACM (for printing)
puts("\nwelcome to the CuVoodoo sound lever enforcer\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 wachtdog 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 internal RTC: ");
#if defined(BLUE_PILL) || defined(STLINKV2) || defined(BLASTER) // for boards without a Low Speed External oscillator
// note: the blue pill LSE oscillator is affected when toggling the onboard LED, thus prefer the HSE
rtc_auto_awake(RCC_HSE, 8000000 / 128 / RTC_TICKS_SECOND - 1); // use High Speed External oscillator (8 MHz / 128) as RTC clock (VBAT can't be used to keep the RTC running)
#else // for boards with an precise Low Speed External oscillator
rtc_auto_awake(RCC_LSE, 32768 / RTC_TICKS_SECOND - 1); // ensure internal RTC is on, uses the 32.678 kHz LSE, and the prescale is set to our tick speed, else update backup registers accordingly (power off the micro-controller for the change to take effect)
#endif
rtc_interrupt_enable(RTC_SEC); // enable RTC interrupt on "seconds"
nvic_enable_irq(NVIC_RTC_IRQ); // allow the RTC to interrupt
time_start = rtc_get_counter_val(); // get start time from internal RTC
puts("OK\n");
puts("setup relay: ");
gpio_set(GPIO_PORT(RELAY_PIN), GPIO_PIN(RELAY_PIN)); // idle not activated
gpio_set_mode(GPIO_PORT(RELAY_PIN), GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_OPENDRAIN, GPIO_PIN(RELAY_PIN)); // set pin as output (sink to enable)
puts("OK\n");
puts("setup 7-segment display: ");
led_tm1637_setup();
led_tm1637_brightness(LED_TM1637_14DIV16); // set maximum brightness
led_tm1637_time(88, 88); // show test pattern
led_tm1637_on();
puts("OK\n");
puts("setup SPP receiver: ");
spp_rx_setup();
puts("OK\n");
puts("read sound level settings: ");
flash_internal_eeprom_setup(1); // dedicate one page to store the settings
if (sound_level_load()) {
puts("set");
} else {
puts("default");
}
puts(" values\n");
command_sound_level_threshold(NULL); // show value
command_sound_level_duration(NULL); // show value
// show sound level
iwdg_reset(); // kick the dog
led_tm1637_number(sound_level_threshold, false); // display threshold
sleep_ms(1000); // wait some time for the user to read
iwdg_reset(); // kick the dog
led_tm1637_text(" dBa"); // display unit
sleep_ms(1000); // wait some time for the user to read
iwdg_reset(); // kick the dog
led_tm1637_number(sound_level_duration, false); // display duration
sleep_ms(1000); // wait some time for the user to read
iwdg_reset(); // kick the dog
led_tm1637_text(" sec"); // display unit
sleep_ms(1000); // wait some time for the user to read
iwdg_reset(); // kick the dog
led_tm1637_brightness(LED_TM1637_1DIV16); // set minimum brightness
led_tm1637_number(0, false); // show measurement
// 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
uint32_t sound_level_valid = 0; // last time a valid value has been received
uint32_t sound_level_under = rtc_get_counter_val(); // last time the threshold has been exceeded
bool sound_level_invalid = false; // no value has been received for some time
bool sound_level_exceeded = false; // the level has exceeded the threshold longer than the duration
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(); // show activity
char c = user_input_get(); // store receive character
terminal_send(c); // send received character to terminal
}
if (rtc_internal_tick_flag) { // the internal RTC ticked
rtc_internal_tick_flag = false; // reset flag
action = true; // action has been performed
if (0 == (rtc_get_counter_val() % RTC_TICKS_SECOND)) { // one second has passed
//led_toggle(); // heartbeat
if (sound_level_exceeded) {
led_tm1637_brightness(LED_TM1637_14DIV16); // set maximum brightness
if ((rtc_get_counter_val() / RTC_TICKS_SECOND) % 2) {
led_tm1637_text("too ");
} else {
led_tm1637_text("loud");
}
} else if (!sound_level_invalid && (((rtc_get_counter_val() - sound_level_valid) / RTC_TICKS_SECOND) >= 3)) { // no value received
sound_level_invalid = true; // remember the value is invalid
led_tm1637_number(0, false); // display empty number
led_tm1637_brightness(LED_TM1637_1DIV16); // set minimum brightness
} else if (!sound_level_exceeded && sound_level_valid > sound_level_under && (((rtc_get_counter_val() - sound_level_under) / RTC_TICKS_SECOND) >= sound_level_duration)) { // sound level exceeded for too long
sound_level_exceeded = true; // remember the value exceeded
led_on(); // light up reset switch
gpio_clear(GPIO_PORT(RELAY_PIN), GPIO_PIN(RELAY_PIN)); // enable relay
}
}
}
if (spp_rx_input_available) {
action = true; // action has been performed
//led_toggle(); // show activity
const char c = spp_rx_input_get(); // get the received data (also clears the flag)
if (!sound_level_exceeded) {
if (spp_input_i < LENGTH(spp_input_buffer) - 1) { // only store when there is enough space
spp_input_buffer[spp_input_i++] = c; // store received data
spp_input_buffer[spp_input_i] = '\0'; // end string
}
if ('\n' == c) { // end of line received
const uint8_t sound_level = parse_measurement(spp_input_buffer); // parse and display the received measurement
spp_input_i = 0; // reset buffer for next line
if (sound_level) {
sound_level_valid = rtc_get_counter_val(); // remember we got a valid value
if (sound_level_show) {
printf("%u dBa\n", sound_level);
}
led_tm1637_number(sound_level, false); // display number
if (sound_level_invalid) {
sound_level_invalid = false; // remember we got a value
sound_level_under = sound_level_valid; // remember the value is under the threshold
}
if (sound_level < sound_level_threshold) {
led_tm1637_brightness(LED_TM1637_1DIV16); // set minimum brightness
sound_level_under = sound_level_valid; // remember the value is under the threshold
} else {
led_tm1637_brightness(LED_TM1637_14DIV16); // set maximum brightness
}
}
} // end of line received
} // !sound_level_exceeded
} // spp_rx_input_available
if (action) { // go to sleep if nothing had to be done, else recheck for activity
action = false;
} else {
__WFI(); // go to sleep
}
} // main loop
}
/** @brief interrupt service routine called when tick passed on RTC */
void rtc_isr(void)
{
rtc_clear_flag(RTC_SEC); // clear flag
rtc_internal_tick_flag = true; // notify to show new time
}