Float voltage to int (#444)

* Change voltage float to millivolt integer
* Explain the ADC to milliVolts conversion

3 files changed, 5 insertions, 26 deletions

diff --git a/src/displayapp/screens/BatteryInfo.cpp b/src/displayapp/screens/BatteryInfo.cpp
index 1ab8b0a..87c8b4b 100644
--- a/src/displayapp/screens/BatteryInfo.cpp
+++ b/src/displayapp/screens/BatteryInfo.cpp
@@ -46,16 +46,9 @@ BatteryInfo::BatteryInfo(Pinetime::Applications::DisplayApp* app, Pinetime::Cont
   lv_label_set_align(percent, LV_LABEL_ALIGN_LEFT);
   lv_obj_align(percent, nullptr, LV_ALIGN_CENTER, 0, -60);
 
-  // hack to not use the flot functions from printf
-  uint8_t batteryVoltageBytes[2];
-  batteryVoltageBytes[1] = static_cast<uint8_t>(batteryVoltage); // truncate whole numbers
-  batteryVoltageBytes[0] =
-    static_cast<uint8_t>((batteryVoltage - batteryVoltageBytes[1]) * 100); // remove whole part of flt and shift 2 places over
-  //
-
   voltage = lv_label_create(lv_scr_act(), nullptr);
   lv_obj_set_style_local_text_color(voltage, LV_LABEL_PART_MAIN, LV_STATE_DEFAULT, lv_color_hex(0xC6A600));
-  lv_label_set_text_fmt(voltage, "%1i.%02i volts", batteryVoltageBytes[1], batteryVoltageBytes[0]);
+  lv_label_set_text_fmt(voltage, "%1i.%02i volts", batteryVoltage / 1000, batteryVoltage % 1000 / 10);
   lv_label_set_align(voltage, LV_LABEL_ALIGN_CENTER);
   lv_obj_align(voltage, nullptr, LV_ALIGN_CENTER, 0, 95);
 
@@ -129,13 +122,7 @@ void BatteryInfo::UpdateScreen() {
   }
 
   lv_obj_align(status, charging_bar, LV_ALIGN_OUT_BOTTOM_MID, 0, 20);
-  // hack to not use the flot functions from printf
-  uint8_t batteryVoltageBytes[2];
-  batteryVoltageBytes[1] = static_cast<uint8_t>(batteryVoltage); // truncate whole numbers
-  batteryVoltageBytes[0] =
-    static_cast<uint8_t>((batteryVoltage - batteryVoltageBytes[1]) * 100); // remove whole part of flt and shift 2 places over
-  //
-  lv_label_set_text_fmt(voltage, "%1i.%02i volts", batteryVoltageBytes[1], batteryVoltageBytes[0]);
+  lv_label_set_text_fmt(voltage, "%1i.%02i volts", batteryVoltage / 1000, batteryVoltage % 1000 / 10);
 }
 
 bool BatteryInfo::Refresh() {
diff --git a/src/displayapp/screens/BatteryInfo.h b/src/displayapp/screens/BatteryInfo.h
index 8805db5..346dc57 100644
--- a/src/displayapp/screens/BatteryInfo.h
+++ b/src/displayapp/screens/BatteryInfo.h
@@ -37,7 +37,7 @@ namespace Pinetime {
 
         int8_t animation = 0;
         int8_t batteryPercent = -1;
-        float batteryVoltage = 0.0f;
+        uint16_t batteryVoltage = 0;
       };
     }
   }
diff --git a/src/displayapp/screens/SystemInfo.cpp b/src/displayapp/screens/SystemInfo.cpp
index 1e90bf4..5ae3a59 100644
--- a/src/displayapp/screens/SystemInfo.cpp
+++ b/src/displayapp/screens/SystemInfo.cpp
@@ -104,8 +104,6 @@ std::unique_ptr<Screen> SystemInfo::CreateScreen1() {
 
 std::unique_ptr<Screen> SystemInfo::CreateScreen2() {
   auto batteryPercent = static_cast<uint8_t>(batteryController.PercentRemaining());
-  float batteryVoltage = batteryController.Voltage();
-
   auto resetReason = [this]() {
     switch (watchdog.ResetReason()) {
       case Drivers::Watchdog::ResetReasons::Watchdog:
@@ -144,18 +142,13 @@ std::unique_ptr<Screen> SystemInfo::CreateScreen2() {
   uptimeSeconds = uptimeSeconds % secondsInAMinute;
   // TODO handle more than 100 days of uptime
 
-  // hack to not use the flot functions from printf
-  uint8_t batteryVoltageBytes[2];
-  batteryVoltageBytes[1] = static_cast<uint8_t>(batteryVoltage); // truncate whole numbers
-  batteryVoltageBytes[0] = static_cast<uint8_t>((batteryVoltage - batteryVoltageBytes[1]) * 100); // remove whole part of flt and shift 2 places over
-
   lv_obj_t* label = lv_label_create(lv_scr_act(), nullptr);
   lv_label_set_recolor(label, true);
   lv_label_set_text_fmt(label,
                         "#444444 Date# %02d/%02d/%04d\n"
                         "#444444 Time# %02d:%02d:%02d\n"
                         "#444444 Uptime#\n %02lud %02lu:%02lu:%02lu\n"
-                        "#444444 Battery# %d%%/%1i.%02iv\n"
+                        "#444444 Battery# %d%%/%03imV\n"
                         "#444444 Backlight# %s\n"
                         "#444444 Last reset# %s\n"
                         "#444444 Accel.# %s\n",
@@ -170,8 +163,7 @@ std::unique_ptr<Screen> SystemInfo::CreateScreen2() {
                         uptimeMinutes,
                         uptimeSeconds,
                         batteryPercent,
-                        batteryVoltageBytes[1],
-                        batteryVoltageBytes[0],
+                        batteryController.Voltage(),
                         brightnessController.ToString(),
                         resetReason,
                         ToString(motionController.DeviceType()));