aod: lower lcd voltage

Author: mark9064

src/drivers/St7789.cpp

@@ -28,6 +28,7 @@ void St7789::Init() {
   NormalModeOn();
   SetVdv();
   PowerControl();
+  GateControl();
   DisplayOn();
 }
 
@@ -190,6 +191,12 @@ void St7789::PowerControl() {
   WriteData(0xb3);
 }
 
+void St7789::GateControl() {
+  WriteCommand(static_cast<uint8_t>(Commands::GateControl));
+  // Lowest possible VGL/VGH
+  WriteData(0x00);
+}
+
 void St7789::SetAddrWindow(uint16_t x0, uint16_t y0, uint16_t x1, uint16_t y1) {
   WriteCommand(static_cast<uint8_t>(Commands::ColumnAddressSet));
   uint8_t colArgs[] = {

src/drivers/St7789.h

@@ -55,6 +55,7 @@ namespace Pinetime {
       void DisplayOn();
       void DisplayOff();
       void PowerControl();
+      void GateControl();
 
       void SetAddrWindow(uint16_t x0, uint16_t y0, uint16_t x1, uint16_t y1);
       void SetVdv();
@@ -84,6 +85,7 @@ namespace Pinetime {
         Command2Enable = 0xdf,
         PowerControl1 = 0xd0,
         PowerControl2 = 0xe8,
+        GateControl = 0xb7,
       };
       void WriteData(uint8_t data);
       void WriteData(const uint8_t* data, size_t size);