Backup and restore vertical scroll offset when goind to sleep/wakeup to avoid scrambled display on wake-up.

2 files changed, 3 insertions, 0 deletions

diff --git a/src/drivers/St7789.cpp b/src/drivers/St7789.cpp
index 1f6e6d3..db7c27e 100644
--- a/src/drivers/St7789.cpp
+++ b/src/drivers/St7789.cpp
@@ -131,6 +131,7 @@ void St7789::VerticalScrollDefinition(uint16_t topFixedLines, uint16_t scrollLin
 }
 
 void St7789::VerticalScrollStartAddress(uint16_t line) {
+  verticalScrollingStartAddress = line;
   WriteCommand(static_cast<uint8_t>(Commands::VerticalScrollStartAddress));
   WriteData(line >> 8u);
   WriteData(line & 0x00ffu);
@@ -189,5 +190,6 @@ void St7789::Wakeup() {
   RowAddressSet();
   DisplayInversionOn();
   NormalModeOn();
+  VerticalScrollStartAddress(verticalScrollingStartAddress);
   DisplayOn();
 }
diff --git a/src/drivers/St7789.h b/src/drivers/St7789.h
index fb57f28..3721b18 100644
--- a/src/drivers/St7789.h
+++ b/src/drivers/St7789.h
@@ -31,6 +31,7 @@ namespace Pinetime {
       private:
         SpiMaster& spi;
         uint8_t pinDataCommand;
+        uint8_t verticalScrollingStartAddress = 0;
 
         void HardwareReset();
         void SoftwareReset();