Detect full charge and improve watchface display

src/components/battery/BatteryController.cpp

@@ -19,6 +19,12 @@ void Battery::Update() {
   isCharging = !nrf_gpio_pin_read(chargingPin);
   isPowerPresent = !nrf_gpio_pin_read(powerPresentPin);
 
+  if (isPowerPresent && !isCharging) {
+    isFull = true;
+  } else if (!isPowerPresent) {
+    isFull = false;
+  }
+
   if (isReading) {
     return;
   }
@@ -65,12 +71,12 @@ void Battery::SaadcEventHandler(nrfx_saadc_evt_t const* p_event) {
     // p_event->data.done.p_buffer[0] = (adc_voltage / reference_voltage) * 1024
     voltage = p_event->data.done.p_buffer[0] * (8 * 600) / 1024;
 
-    if (voltage > battery_max) {
+    if (isFull) {
       percentRemaining = 100;
     } else if (voltage < battery_min) {
       percentRemaining = 0;
     } else {
-      percentRemaining = (voltage - battery_min) * 100 / (battery_max - battery_min);
+      percentRemaining = std::min((voltage - battery_min) * 100 / (battery_max - battery_min), 99);
     }
 
     nrfx_saadc_uninit();

src/components/battery/BatteryController.h

@@ -23,13 +23,19 @@ namespace Pinetime {
       }
 
       bool IsCharging() const {
-        return isCharging;
+        // isCharging will go up and down when fully charged
+        // isFull makes sure this returns false while fully charged.
+        return isCharging && !isFull;
       }
 
       bool IsPowerPresent() const {
         return isPowerPresent;
       }
 
+      bool IsFull() const {
+        return isFull;
+      }
+
     private:
       static Battery* instance;
       nrf_saadc_value_t saadc_value;
@@ -40,6 +46,7 @@ namespace Pinetime {
       uint16_t voltage = 0;
       uint8_t percentRemaining = 0;
 
+      bool isFull = false;
       bool isCharging = false;
       bool isPowerPresent = false;