2 files changed, 40 insertions, 10 deletions

diff --git a/src/components/battery/BatteryController.cpp b/src/components/battery/BatteryController.cpp
index beca95c4..4a7a2345 100644
--- a/src/components/battery/BatteryController.cpp
+++ b/src/components/battery/BatteryController.cpp
@@ -66,6 +66,8 @@ void Battery::SaadcEventHandler(nrfx_saadc_evt_t const * p_event) {
       percentRemaining = std::max(percentRemaining, 0);
       percentRemaining = std::min(percentRemaining, 100);
 
+      percentRemainingBuffer.insert(percentRemaining);
+
       nrfx_saadc_uninit();
     }
   }
@@ -73,11 +75,3 @@ void Battery::SaadcEventHandler(nrfx_saadc_evt_t const * p_event) {
 void Battery::adcCallbackStatic(nrfx_saadc_evt_t const *event) {
     instance->SaadcEventHandler(event);
 }
-
-int Battery::PercentRemaining() {
-  return percentRemaining;
-}
-
-float Battery::Voltage() {
-  return voltage;
-}
\ No newline at end of file
diff --git a/src/components/battery/BatteryController.h b/src/components/battery/BatteryController.h
index 6a0c7dff..2776687b 100644
--- a/src/components/battery/BatteryController.h
+++ b/src/components/battery/BatteryController.h
@@ -7,6 +7,38 @@
 namespace Pinetime {
   namespace Controllers {
 
+    /** A simple circular buffer that can be used to average 
+     out the sensor values. The total capacity of the CircBuffer  
+    is given as the template parameter N.
+    */ 
+    template <int N> 
+    class CircBuffer {
+    public:
+      CircBuffer() : arr{}, sz{}, cap{N}, head{} {}
+      /**
+     insert member function overwrites the next data to the current 
+    HEAD and moves the HEAD to the newly inserted value.
+    */ 
+      void insert(const int num) {
+        head %= cap;
+        arr[head++] = num;
+        if (sz != cap) {
+          sz++;
+        }
+      }
+
+      int GetAverage() const {
+        int sum = std::accumulate(arr.begin(), arr.end(), 0);
+        return (sum / sz);
+      }
+
+    private:
+      std::array<int, N> arr; /**< internal array used to store the values*/
+      uint8_t sz; /**< The current size of the array.*/
+      uint8_t cap; /**< Total capacity of the CircBuffer.*/
+      uint8_t head; /**< The current head of the CircBuffer*/
+    };
+
     class Battery {
       public:
 
@@ -15,8 +47,9 @@ namespace Pinetime {
         void Init();
         void Update();
         
-        int PercentRemaining();
-        float Voltage();
+        int PercentRemaining() const { return percentRemainingBuffer.GetAverage(); }
+
+        float Voltage() const { return voltage; }
 
         bool IsCharging() const { return isCharging; }
         bool IsPowerPresent() const { return isPowerPresent; }
@@ -24,6 +57,9 @@ namespace Pinetime {
       private:
         static Battery *instance;
         nrf_saadc_value_t  saadc_value;
+        
+        static constexpr uint8_t percentRemainingSamples = 10;
+        CircBuffer<percentRemainingSamples> percentRemainingBuffer {};
 
         static constexpr uint32_t chargingPin = 12;
         static constexpr uint32_t powerPresentPin = 19;