feat(Power): support EXT_PWR_DETECT_MODE & EXT_PWR_DETECT_VALUE, simplify EXT_PWR_DETECT (#10140)

Assisted-by: Claude Sonnet 4.6 <noreply@anthropic.com>

Signed-off-by: Andrew Yong <me@ndoo.sg>

src/Power.cpp

@@ -94,6 +94,20 @@ static const adc_atten_t atten = ADC_ATTENUATION;
 #endif
 #endif // BATTERY_PIN && ARCH_ESP32
 
+#ifdef EXT_PWR_DETECT
+#ifndef EXT_PWR_DETECT_MODE
+#define EXT_PWR_DETECT_MODE INPUT
+// If using internal pull resistors, we can infer EXT_PWR_DETECT_VALUE
+#elif EXT_PWR_DETECT_MODE == INPUT_PULLUP
+#define EXT_PWR_DETECT_VALUE LOW
+#elif EXT_PWR_DETECT_MODE == INPUT_PULLDOWN
+#define EXT_PWR_DETECT_VALUE HIGH
+#endif
+#ifndef EXT_PWR_DETECT_VALUE
+#define EXT_PWR_DETECT_VALUE HIGH
+#endif
+#endif
+
 #ifdef EXT_CHRG_DETECT
 #ifndef EXT_CHRG_DETECT_MODE
 #define EXT_CHRG_DETECT_MODE INPUT
@@ -470,28 +484,14 @@ class AnalogBatteryLevel : public HasBatteryLevel
     virtual bool isBatteryConnect() override { return getBatteryPercent() != -1; }
 #endif
 
-    /// If we see a battery voltage higher than physics allows - assume charger is
-    /// pumping in power On some boards we don't have the power management chip
-    /// (like AXPxxxx) so we use EXT_PWR_DETECT GPIO pin to detect external power
-    /// source
+    // Detect if an external power source is connected if we don’t have a PMIC;
+    // Firstly prefer EXT_PWR_DETECT GPIO if available,
+    // secondly try an nRF52-specific routine on some variants,
+    // lastly provide a fallback to indicate external power when fully charged.
     virtual bool isVbusIn() override
     {
 #ifdef EXT_PWR_DETECT
-#if defined(HELTEC_CAPSULE_SENSOR_V3) || defined(HELTEC_SENSOR_HUB)
-        // if external powered that pin will be pulled down
-        if (digitalRead(EXT_PWR_DETECT) == LOW) {
-            return true;
-        }
-        // if it's not LOW - check the battery
-#else
-        // if external powered that pin will be pulled up
-        if (digitalRead(EXT_PWR_DETECT) == HIGH) {
-            return true;
-        }
-        // 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;
+        return digitalRead(EXT_PWR_DETECT) == EXT_PWR_DETECT_VALUE;
 
 // technically speaking this should work for all(?) NRF52 boards
 // but needs testing across multiple devices. NRF52 USB would not even work if
@@ -647,11 +647,7 @@ Power::Power() : OSThread("Power")
 bool Power::analogInit()
 {
 #ifdef EXT_PWR_DETECT
-#if defined(HELTEC_CAPSULE_SENSOR_V3) || defined(HELTEC_SENSOR_HUB)
-    pinMode(EXT_PWR_DETECT, INPUT_PULLUP);
-#else
-    pinMode(EXT_PWR_DETECT, INPUT);
-#endif
+    pinMode(EXT_PWR_DETECT, EXT_PWR_DETECT_MODE);
 #endif
 #ifdef EXT_CHRG_DETECT
     pinMode(EXT_CHRG_DETECT, EXT_CHRG_DETECT_MODE);
@@ -1907,7 +1903,7 @@ SerialBatteryLevel serialBatteryLevel;
 bool Power::serialBatteryInit()
 {
 #ifdef EXT_PWR_DETECT
-    pinMode(EXT_PWR_DETECT, INPUT);
+    pinMode(EXT_PWR_DETECT, EXT_PWR_DETECT_MODE);
 #endif
 #ifdef EXT_CHRG_DETECT
     pinMode(EXT_CHRG_DETECT, EXT_CHRG_DETECT_MODE);

variants/esp32s3/heltec_capsule_sensor_v3/variant.h

@@ -1,6 +1,7 @@
 #define LED_POWER 33
 #define LED_POWER2 34
 #define EXT_PWR_DETECT 35
+#define EXT_PWR_DETECT_MODE INPUT_PULLUP
 
 #define BUTTON_PIN 18
 #define BUTTON_ACTIVE_LOW false

variants/esp32s3/heltec_sensor_hub/variant.h

@@ -1,4 +1,5 @@
 #define EXT_PWR_DETECT 20
+#define EXT_PWR_DETECT_MODE INPUT_PULLUP
 
 #define BUTTON_PIN 17
 #define BUTTON_ACTIVE_LOW false