Detect charging status by measuring current flow with configured INA219 battery sensor

src/Power.cpp

@@ -413,7 +413,20 @@ class AnalogBatteryLevel : public HasBatteryLevel
 #ifdef EXT_CHRG_DETECT
         return digitalRead(EXT_CHRG_DETECT) == ext_chrg_detect_value;
 #else
+#if HAS_TELEMETRY && !MESHTASTIC_EXCLUDE_ENVIRONMENTAL_SENSOR && !defined(ARCH_PORTDUINO) && !defined(ARCH_STM32WL) &&           \
+    !defined(DISABLE_INA_CHARGING_DETECTION)
+        if (hasINA()) {
+            // get current flow from INA sensor - negative value means power flowing into the battery
+            // default assuming  BATTERY+  <--> INA_VIN+ <--> SHUNT RESISTOR <--> INA_VIN- <--> LOAD
+            LOG_DEBUG("Using INA on I2C addr 0x%x for charging detection", config.power.device_battery_ina_address);
+#if defined(INA_CHARGING_DETECTION_INVERT)
+            return getINACurrent() > 0;
+#else
+            return getINACurrent() < 0;
+#endif
+        }
         return isBatteryConnect() && isVbusIn();
+#endif
 #endif
     }
 
@@ -460,6 +473,17 @@ class AnalogBatteryLevel : public HasBatteryLevel
         return 0;
     }
 
+    int16_t getINACurrent()
+    {
+        if (nodeTelemetrySensorsMap[meshtastic_TelemetrySensorType_INA219].first == config.power.device_battery_ina_address) {
+            return ina219Sensor.getCurrentMa();
+        } else if (nodeTelemetrySensorsMap[meshtastic_TelemetrySensorType_INA3221].first ==
+                   config.power.device_battery_ina_address) {
+            return ina3221Sensor.getCurrentMa();
+        }
+        return 0;
+    }
+
     bool hasINA()
     {
         if (!config.power.device_battery_ina_address) {

src/modules/Telemetry/Sensor/CurrentSensor.h

@@ -0,0 +1,13 @@
+#include "configuration.h"
+
+#if !MESHTASTIC_EXCLUDE_ENVIRONMENTAL_SENSOR
+
+#pragma once
+
+class CurrentSensor
+{
+  public:
+    virtual int16_t getCurrentMa() = 0;
+};
+
+#endif

src/modules/Telemetry/Sensor/INA219Sensor.cpp

@@ -45,4 +45,9 @@ uint16_t INA219Sensor::getBusVoltageMv()
     return lround(ina219.getBusVoltage_V() * 1000);
 }
 
+int16_t INA219Sensor::getCurrentMa()
+{
+    return lround(ina219.getCurrent_mA());
+}
+
 #endif

src/modules/Telemetry/Sensor/INA219Sensor.h

@@ -3,11 +3,12 @@
 #if HAS_TELEMETRY && !MESHTASTIC_EXCLUDE_ENVIRONMENTAL_SENSOR
 
 #include "../mesh/generated/meshtastic/telemetry.pb.h"
+#include "CurrentSensor.h"
 #include "TelemetrySensor.h"
 #include "VoltageSensor.h"
 #include <Adafruit_INA219.h>
 
-class INA219Sensor : public TelemetrySensor, VoltageSensor
+class INA219Sensor : public TelemetrySensor, VoltageSensor, CurrentSensor
 {
   private:
     Adafruit_INA219 ina219;
@@ -20,6 +21,7 @@ class INA219Sensor : public TelemetrySensor, VoltageSensor
     virtual int32_t runOnce() override;
     virtual bool getMetrics(meshtastic_Telemetry *measurement) override;
     virtual uint16_t getBusVoltageMv() override;
+    virtual int16_t getCurrentMa() override;
 };
 
 #endif

src/modules/Telemetry/Sensor/INA3221Sensor.cpp

@@ -102,4 +102,9 @@ uint16_t INA3221Sensor::getBusVoltageMv()
     return lround(ina3221.getVoltage(BAT_CH) * 1000);
 }
 
+int16_t INA3221Sensor::getCurrentMa()
+{
+    return lround(ina3221.getCurrent(BAT_CH));
+}
+
 #endif

src/modules/Telemetry/Sensor/INA3221Sensor.h

@@ -3,11 +3,12 @@
 #if HAS_TELEMETRY && !MESHTASTIC_EXCLUDE_ENVIRONMENTAL_SENSOR
 
 #include "../mesh/generated/meshtastic/telemetry.pb.h"
+#include "CurrentSensor.h"
 #include "TelemetrySensor.h"
 #include "VoltageSensor.h"
 #include <INA3221.h>
 
-class INA3221Sensor : public TelemetrySensor, VoltageSensor
+class INA3221Sensor : public TelemetrySensor, VoltageSensor, CurrentSensor
 {
   private:
     INA3221 ina3221 = INA3221(INA3221_ADDR42_SDA);
@@ -35,6 +36,7 @@ class INA3221Sensor : public TelemetrySensor, VoltageSensor
     int32_t runOnce() override;
     bool getMetrics(meshtastic_Telemetry *measurement) override;
     virtual uint16_t getBusVoltageMv() override;
+    virtual int16_t getCurrentMa() override;
 };
 
 struct _INA3221Measurement {