Prefer EXT_PWR_DETECT pin over chargingVolt to detect power unplugged (#9511)

src/Power.cpp

@@ -459,6 +459,8 @@ class AnalogBatteryLevel : public HasBatteryLevel
         }
         // if it's not HIGH - check the battery
 #endif
+        // If we have an EXT_PWR_DETECT pin and it indicates no external power, believe it.
+        return false;
 
 // technically speaking this should work for all(?) NRF52 boards
 // but needs testing across multiple devices. NRF52 USB would not even work if

src/main.cpp

@@ -7,7 +7,6 @@
 #include "NodeDB.h"
 #include "PowerFSM.h"
 #include "PowerMon.h"
-#include "RadioLibInterface.h"
 #include "ReliableRouter.h"
 #include "airtime.h"
 #include "buzz.h"
@@ -194,8 +193,6 @@ bool kb_found = false;
 // global bool to record that on-screen keyboard (OSK) is present
 bool osk_found = false;
 
-unsigned long last_listen = 0;
-
 // The I2C address of the RTC Module (if found)
 ScanI2C::DeviceAddress rtc_found = ScanI2C::ADDRESS_NONE;
 // The I2C address of the Accelerometer (if found)
@@ -1169,12 +1166,6 @@ void loop()
 #endif
     power->powerCommandsCheck();
 
-    if (RadioLibInterface::instance != nullptr && !Throttle::isWithinTimespanMs(last_listen, 1000 * 60) &&
-        !(RadioLibInterface::instance->isSending() || RadioLibInterface::instance->isActivelyReceiving())) {
-        RadioLibInterface::instance->startReceive();
-        LOG_DEBUG("attempting AGC reset");
-    }
-
 #ifdef DEBUG_STACK
     static uint32_t lastPrint = 0;
     if (!Throttle::isWithinTimespanMs(lastPrint, 10 * 1000L)) {

src/main.h

@@ -33,7 +33,6 @@ extern ScanI2C::DeviceAddress cardkb_found;
 extern uint8_t kb_model;
 extern bool kb_found;
 extern bool osk_found;
-extern unsigned long last_listen;
 extern ScanI2C::DeviceAddress rtc_found;
 extern ScanI2C::DeviceAddress accelerometer_found;
 extern ScanI2C::FoundDevice rgb_found;

src/mesh/RadioLibInterface.cpp

@@ -514,8 +514,6 @@ void RadioLibInterface::handleReceiveInterrupt()
 
 void RadioLibInterface::startReceive()
 {
-    // Note the updated timestamp, to avoid unneeded AGC resets
-    last_listen = millis();
     isReceiving = true;
     powerMon->setState(meshtastic_PowerMon_State_Lora_RXOn);
 }