Don't attempt to save NodeDB on low-batt shutdown to prevent FS corruption

src/Power.cpp

@@ -614,7 +614,7 @@ void Power::shutdown()
 #ifdef PIN_LED3
     ledOff(PIN_LED3);
 #endif
-    doDeepSleep(DELAY_FOREVER, false);
+    doDeepSleep(DELAY_FOREVER, false, false);
 #endif
 }
 

src/PowerFSM.cpp

@@ -55,9 +55,14 @@ static void sdsEnter()
 {
     LOG_DEBUG("State: SDS");
     // FIXME - make sure GPS and LORA radio are off first - because we want close to zero current draw
-    doDeepSleep(Default::getConfiguredOrDefaultMs(config.power.sds_secs), false);
+    doDeepSleep(Default::getConfiguredOrDefaultMs(config.power.sds_secs), false, false);
 }
 
+static void lowBattSDSEnter()
+{
+    LOG_DEBUG("State: Lower batt SDS");
+    doDeepSleep(Default::getConfiguredOrDefaultMs(config.power.sds_secs), false, true);
+}
 extern Power *power;
 
 static void shutdownEnter()
@@ -247,6 +252,7 @@ static void bootEnter()
 
 State stateSHUTDOWN(shutdownEnter, NULL, NULL, "SHUTDOWN");
 State stateSDS(sdsEnter, NULL, NULL, "SDS");
+State stateLowBattSDS(lowBattSDSEnter, NULL, NULL, "SDS");
 State stateLS(lsEnter, lsIdle, lsExit, "LS");
 State stateNB(nbEnter, NULL, NULL, "NB");
 State stateDARK(darkEnter, NULL, NULL, "DARK");
@@ -291,12 +297,12 @@ void PowerFSM_setup()
                             "Press"); // Allow button to work while in serial API
 
     // Handle critically low power battery by forcing deep sleep
-    powerFSM.add_transition(&stateBOOT, &stateSDS, EVENT_LOW_BATTERY, NULL, "LowBat");
-    powerFSM.add_transition(&stateLS, &stateSDS, EVENT_LOW_BATTERY, NULL, "LowBat");
-    powerFSM.add_transition(&stateNB, &stateSDS, EVENT_LOW_BATTERY, NULL, "LowBat");
-    powerFSM.add_transition(&stateDARK, &stateSDS, EVENT_LOW_BATTERY, NULL, "LowBat");
-    powerFSM.add_transition(&stateON, &stateSDS, EVENT_LOW_BATTERY, NULL, "LowBat");
-    powerFSM.add_transition(&stateSERIAL, &stateSDS, EVENT_LOW_BATTERY, NULL, "LowBat");
+    powerFSM.add_transition(&stateBOOT, &stateLowBattSDS, EVENT_LOW_BATTERY, NULL, "LowBat");
+    powerFSM.add_transition(&stateLS, &stateLowBattSDS, EVENT_LOW_BATTERY, NULL, "LowBat");
+    powerFSM.add_transition(&stateNB, &stateLowBattSDS, EVENT_LOW_BATTERY, NULL, "LowBat");
+    powerFSM.add_transition(&stateDARK, &stateLowBattSDS, EVENT_LOW_BATTERY, NULL, "LowBat");
+    powerFSM.add_transition(&stateON, &stateLowBattSDS, EVENT_LOW_BATTERY, NULL, "LowBat");
+    powerFSM.add_transition(&stateSERIAL, &stateLowBattSDS, EVENT_LOW_BATTERY, NULL, "LowBat");
 
     // Handle being told to power off
     powerFSM.add_transition(&stateBOOT, &stateSHUTDOWN, EVENT_SHUTDOWN, NULL, "Shutdown");

src/modules/PositionModule.cpp

@@ -364,7 +364,7 @@ int32_t PositionModule::runOnce()
         sleepOnNextExecution = false;
         uint32_t nightyNightMs = Default::getConfiguredOrDefaultMs(config.position.position_broadcast_secs);
         LOG_DEBUG("Sleep for %ims, then awaking to send position again", nightyNightMs);
-        doDeepSleep(nightyNightMs, false);
+        doDeepSleep(nightyNightMs, false, false);
     }
 
     meshtastic_NodeInfoLite *node = nodeDB->getMeshNode(nodeDB->getNodeNum());

src/modules/PowerStressModule.cpp

@@ -111,7 +111,7 @@ int32_t PowerStressModule::runOnce()
                 setBluetoothEnable(true);
                 break;
             case meshtastic_PowerStressMessage_Opcode_CPU_DEEPSLEEP:
-                doDeepSleep(sleep_msec, true);
+                doDeepSleep(sleep_msec, true, true);
                 break;
             case meshtastic_PowerStressMessage_Opcode_CPU_FULLON: {
                 uint32_t start_msec = millis();

src/modules/Telemetry/EnvironmentTelemetry.cpp

@@ -74,7 +74,7 @@ int32_t EnvironmentTelemetryModule::runOnce()
         uint32_t nightyNightMs = Default::getConfiguredOrDefaultMs(moduleConfig.telemetry.environment_update_interval,
                                                                    default_telemetry_broadcast_interval_secs);
         LOG_DEBUG("Sleep for %ims, then awake to send metrics again", nightyNightMs);
-        doDeepSleep(nightyNightMs, true);
+        doDeepSleep(nightyNightMs, true, false);
     }
 
     uint32_t result = UINT32_MAX;

src/modules/Telemetry/HealthTelemetry.cpp

@@ -40,7 +40,7 @@ int32_t HealthTelemetryModule::runOnce()
         uint32_t nightyNightMs = Default::getConfiguredOrDefaultMs(moduleConfig.telemetry.health_update_interval,
                                                                    default_telemetry_broadcast_interval_secs);
         LOG_DEBUG("Sleep for %ims, then awake to send metrics again", nightyNightMs);
-        doDeepSleep(nightyNightMs, true);
+        doDeepSleep(nightyNightMs, true, false);
     }
 
     uint32_t result = UINT32_MAX;

src/modules/Telemetry/PowerTelemetry.cpp

@@ -28,7 +28,7 @@ int32_t PowerTelemetryModule::runOnce()
         uint32_t nightyNightMs = Default::getConfiguredOrDefaultMs(moduleConfig.telemetry.power_update_interval,
                                                                    default_telemetry_broadcast_interval_secs);
         LOG_DEBUG("Sleep for %ims, then awake to send metrics again", nightyNightMs);
-        doDeepSleep(nightyNightMs, true);
+        doDeepSleep(nightyNightMs, true, false);
     }
 
     uint32_t result = UINT32_MAX;

src/sleep.cpp

@@ -187,7 +187,7 @@ static void waitEnterSleep(bool skipPreflight = false)
     notifySleep.notifyObservers(NULL);
 }
 
-void doDeepSleep(uint32_t msecToWake, bool skipPreflight = false)
+void doDeepSleep(uint32_t msecToWake, bool skipPreflight = false, bool skipSaveNodeDb = false)
 {
     if (INCLUDE_vTaskSuspend && (msecToWake == portMAX_DELAY)) {
         LOG_INFO("Enter deep sleep forever");
@@ -219,7 +219,9 @@ void doDeepSleep(uint32_t msecToWake, bool skipPreflight = false)
 
     screen->doDeepSleep(); // datasheet says this will draw only 10ua
 
-    nodeDB->saveToDisk();
+    if (!skipSaveNodeDb) {
+        nodeDB->saveToDisk();
+    }
 
 #ifdef PIN_POWER_EN
     pinMode(PIN_POWER_EN, INPUT); // power off peripherals

src/sleep.h

@@ -4,7 +4,7 @@
 #include "Observer.h"
 #include "configuration.h"
 
-void doDeepSleep(uint32_t msecToWake, bool skipPreflight), cpuDeepSleep(uint32_t msecToWake);
+void doDeepSleep(uint32_t msecToWake, bool skipPreflight, bool skipSaveNodeDb), cpuDeepSleep(uint32_t msecToWake);
 
 #ifdef ARCH_ESP32
 #include "esp_sleep.h"