Fix #133 - force deep sleep if battery reaches 10%

src/PowerFSM.cpp

@@ -153,6 +153,13 @@ void PowerFSM_setup()
     powerFSM.add_transition(&stateDARK, &stateON, EVENT_PRESS, NULL, "Press");
     powerFSM.add_transition(&stateON, &stateON, EVENT_PRESS, screenPress, "Press"); // reenter On to restart our timers
 
+    // 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(&stateDARK, &stateON, EVENT_BLUETOOTH_PAIR, NULL, "Bluetooth pairing");
     powerFSM.add_transition(&stateON, &stateON, EVENT_BLUETOOTH_PAIR, NULL, "Bluetooth pairing");
 

src/PowerFSM.h

@@ -13,6 +13,7 @@
 #define EVENT_BLUETOOTH_PAIR 7
 #define EVENT_NODEDB_UPDATED 8     // NodeDB has a big enough change that we think you should turn on the screen
 #define EVENT_CONTACT_FROM_PHONE 9 // the phone just talked to us over bluetooth
+#define EVENT_LOW_BATTERY 10 // Battery is critically low, go to sleep
 
 extern Fsm powerFSM;
 

src/esp32/main-esp32.cpp

@@ -183,7 +183,7 @@ uint32_t axpDebugRead()
 Periodic axpDebugOutput(axpDebugRead);
 #endif
 
-#define MIN_BAT_MILLIVOLTS 3690 // millivolts. 10% per https://blog.ampow.com/lipo-voltage-chart/
+#define MIN_BAT_MILLIVOLTS 5000 // 3690 // millivolts. 10% per https://blog.ampow.com/lipo-voltage-chart/
 
 /// loop code specific to ESP32 targets
 void esp32Loop()
@@ -226,10 +226,9 @@ void esp32Loop()
         axp.clearIRQ();
     }
 
-    float v = axp.getBattVoltage();
-    DEBUG_MSG("Bat volt %f\n", v);
-    //if(v >= MIN_BAT_MILLIVOLTS / 2 && v < MIN_BAT_MILLIVOLTS) // If we have a battery at all and it is less than 10% full, force deep sleep
-    //    powerFSM.trigger(EVENT_LOW_BATTERY);
+    if (powerStatus.haveBattery && !powerStatus.usb &&
+        axp.getBattVoltage() < MIN_BAT_MILLIVOLTS) // If we have a battery at all and it is less than 10% full, force deep sleep
+        powerFSM.trigger(EVENT_LOW_BATTERY);
 
 #endif // T_BEAM_V10
 }