Updated the Reset_Reason code

examples/Peripherals/Registers/Reset_reason/Reset_reason.ino

@@ -1,7 +1,10 @@
+#include <STM32LowPower.h>
+#include <low_power.h>
+
 /* Last Reset Reason Sketch
 * This sketch will determine what caused the last reset on the STM32 MCU. Most microcontrollers
 * have a register dedicated to storing the last reason of the chip, weather being from a 
-* low power condition, software caused brown-out. Test it by resetting the MCU via the USER button
+* low power condition, software caused or brown-out. Test it by resetting the MCU via holding the USER button,
 * which triggers the Reset_my_MCU() function or unplug the USB cable and repluggit back. Adjust your 
 * UART, USER Button pin and registers accordingly. Use the MCU's datasheet and/or stm32yyyxxx.h for reference.
 * The code is provided "as is" with no liability.
@@ -22,15 +25,17 @@ enum reset_reason {
   WINDOW_WDG = 1 << 4,
   LOW_POWER = 1 << 5,
   OPTION_BYTE_LOADER = 1 << 6,
-  POWER_ON_DOWN = 1 << 7
+  POWER_ON_DOWN = 1 << 7,
+  STANDBY = 1 << 8,
+  WAKEUP = 1 << 9
 };
 
-reset_reason last_reset_reason = UNKNOWN_RESET;
+reset_reason last_reset_reason = UNKNOWN_RESET;  //is initially 0 or unknown
 static int default_button_state = LOW;
 
 void Reset_My_MCU() {
-  // There are a few reset conditions.
-  // Keep the one you wish to use and comment out the others.
+  // There are a few reset conditions. Keep the one you wish to use and comment out the others.
+
   // Below is the Software reset condition
   // NVIC_SystemReset();
 
@@ -69,9 +74,26 @@ void setup() {
 #ifdef RCC_CSR_PORRSTF
   if (LL_RCC_IsActiveFlag_PORRST()) last_reset_reason = (reset_reason)(last_reset_reason | POWER_ON_DOWN);
 #endif
+#if defined(PWR_CSR_SBF) || defined(PWR_SR_SBF) || defined(PWR_SR1_SBF) || defined(PWR_CSR1_SBF) || defined(PWR_PMSR_SBF)
+  if (LL_PWR_IsActiveFlag_SB()) last_reset_reason = (reset_reason)(last_reset_reason | STANDBY);
+#endif
+#if defined(PWR_CSR_WUF)
+  if (LL_PWR_IsActiveFlag_WU()) last_reset_reason = (reset_reason)(last_reset_reason | WAKEUP);
+#endif
+
 
   // Clear reset flags
   LL_RCC_ClearResetFlags();
+#if defined(PWR_SCR_CSBF) || defined(PWR_CR1_CSBF) || defined(PWR_PMCR_CSSF) || defined(PWR_SR_CSSF)
+#if defined(STM32U0xx)
+  LL_PWR_ClearFlag_CSB();
+#else
+  LL_PWR_ClearFlag_SB();
+#endif
+#endif
+#if defined(PWR_CSR_WUF)
+  LL_PWR_ClearFlag_WU();
+#endif
 }
 
 void loop() {
@@ -83,10 +105,11 @@ void loop() {
   if (last_reset_reason & WINDOW_WDG) Serial.println(" - Window Watchdog reset");
   if (last_reset_reason & LOW_POWER) Serial.println(" - Low-power reset");
   if (last_reset_reason & OPTION_BYTE_LOADER) Serial.println(" - Option byte loader reset");
-  if (last_reset_reason & NRST_PIN) Serial.println(" - Pin reset (NRST or software)");  //last case so the rest take precedence before issuing NRST
+  if (last_reset_reason & STANDBY) Serial.println(" - Standby mode reset");
+  if (last_reset_reason & WAKEUP) Serial.println(" - WakeUp flag reset (Pin or RTC)");
   if (last_reset_reason & POWER_ON_DOWN) Serial.println(" - Power on or power down reset");
+  if (last_reset_reason & NRST_PIN) Serial.println(" - Pin reset (NRST or software)");  //last case so the rest take precedence before issuing NRST
   if (last_reset_reason == UNKNOWN_RESET) Serial.println(" - Unknown or no flags set");
-  last_reset_reason = UNKNOWN_RESET;
 
   // Trigger software reset on button press
   if (digitalRead(USER_BTN_PIN) != default_button_state) {