Add BatteryMonitor class to support battery monitoring

components/Monitoring/Monitoring/BatteryMonitor.cpp

@@ -0,0 +1,44 @@
+#include "BatteryMonitor.hpp"
+
+#include <esp_log.h>
+
+static const char *TAG_BAT = "[BatteryMonitor]";
+
+bool BatteryMonitor::setup()
+{
+#if defined(CONFIG_IDF_TARGET_ESP32S3)
+    if (CONFIG_MONITORING_BATTERY_DIVIDER_R_TOP_OHM <= 0)
+    {
+        ESP_LOGE(TAG_BAT, "Invalid divider bottom resistor: %d", CONFIG_MONITORING_BATTERY_DIVIDER_R_TOP_OHM);
+        return false;
+    }
+    scale_ = 1.0f + static_cast<float>(CONFIG_MONITORING_BATTERY_DIVIDER_R_TOP_OHM) / static_cast<float>(CONFIG_MONITORING_BATTERY_DIVIDER_R_BOTTOM_OHM);
+    if (!adc_.init(CONFIG_MONITORING_BATTERY_ADC_GPIO, ADC_ATTEN_DB_12, ADC_BITWIDTH_DEFAULT, CONFIG_MONITORING_BATTERY_SAMPLES))
+    {
+        ESP_LOGE(TAG_BAT, "Battery ADC init failed");
+        return false;
+    }
+    ESP_LOGI(TAG_BAT, "Battery monitor enabled (GPIO=%d, scale=%.3f)", CONFIG_MONITORING_BATTERY_ADC_GPIO, scale_);
+    return true;
+#else
+    ESP_LOGI(TAG_BAT, "Battery monitoring not supported on this target");
+    return false;
+#endif
+}
+
+int BatteryMonitor::getBatteryMilliVolts() const
+{
+#if defined(CONFIG_IDF_TARGET_ESP32S3)
+    if (!adc_.sampleOnce())
+        return 0;
+
+    const int mv_at_adc = adc_.getFilteredMilliVolts();
+    if (mv_at_adc <= 0)
+        return 0;
+
+    const float battery_mv = mv_at_adc * scale_;
+    return static_cast<int>(std::lround(battery_mv));
+#else
+    return 0;
+#endif
+}

components/Monitoring/Monitoring/BatteryMonitor.hpp

@@ -0,0 +1,29 @@
+#pragma once
+#include "AdcSampler.hpp"
+#include <cmath>
+
+class BatteryMonitor
+{
+public:
+    BatteryMonitor() = default;
+    ~BatteryMonitor() = default;
+
+    bool setup();
+
+    // Read once, update filter, and return battery voltage in mV (after divider compensation).
+    int getBatteryMilliVolts() const;
+
+    // Whether monitoring is enabled by Kconfig
+    static constexpr bool isEnabled()
+    {
+#ifdef CONFIG_MONITORING_BATTERY_ENABLE
+        return true;
+#else
+        return false;
+#endif
+    }
+
+private:
+    float scale_{1.0f};
+    mutable AdcSampler adc_;
+};