Customer:
In Inkplate10_Partial_Update_With_Deep_Sleep.ino, there is a comment next to “partialUpdate(true)” that says “Use this only in this scenario, otherwise YOU CAN DAMAGE YOUR SCREEN”. What is “this scenario” exactly? When is it safe or unsafe to use partialUpdate(true)?
Originally submitted via email support on 6 March 2025. Migrated to the forum for community visibility.
Soldered Support:
Partial update with deep sleep normally would not work because partialUpdate uses what was previously in the frame buffer to only change the required pixels. When the device wakes from deep sleep, the frame buffer is empty.
In the example, there is a function which recreates the previous state of the screen. This allows the first refresh after wake to be a partial update. Using partialUpdate(true) forces this behavior: it works because the frame buffer was recreated and filled up, so partialUpdate can use it to change only the pixels that need to be changed.
Using partialUpdate(true) outside this specific scenario - where the frame buffer has not been properly recreated - can damage your screen because the display controller will attempt a partial update without valid reference data.