Customer:
How many times can partials be displayed before doing a normal screen update? I understand that doing it too many times may have an impact on the screen image quality.
It could then be a good idea to add some control in the EInk driver to limit the number of partials transmitted to the display.
Originally submitted via email support on 27 October 2020. Migrated to the forum for community visibility.
Soldered Support:
For the Inkplate 6, you shouldn’t do more than 20 partial refreshes before doing a full refresh. The recommended value is 6.
Future Inkplate will come with newer generations of e-paper displays which will allow much more partial refreshes without the full refresh (up to 1000).
Customer:
During my tests of the ported drivers to ESP-IDF, I encountered an issue that required me a better understanding of the MCP chip. At the beginning of the Inkplate.begin() method, the WAKEUP_SET is launched without having the WAKEUP IO pin directed to be OUTPUT on the MCP. I suspect that the code is working fine on the Arduino because the time required to bootstrap is short enough that the MCP doesn’t complete its internal reset sequence completely. On the ESP-IDF, the bootstrap maybe a bit longer. The normal MCP state after reset is to have all his IO pins defined as INPUTs. Because of that, the Power controller wasn’t starting properly. I moved the mcpBegin() and the pinModeMCP(WAKEUP, OUTPUT); call before the WAKEUP_SET to get it working.
Soldered Support:
We tested the new screen with 300 partial refreshes and found no damages to the screen and little or none ghosting. Thanks for reporting on this code bit as well - makes sense. I have forwarded this to my guys and they will check it out.