Auto Clear Display

[Paul@Port]

It is normally great that the display holds its image when no power (it greatly reduces power consuption), 
but...
I have an application where it seems best for the display to indicate when power is lost, possible by erasing or filling with a pattern.

Is there any way to set the driver IC to erase the display or otherwise indicate loss of power?
Even just erasing or changing a portion of the display (i.e. where normally an OK or connected icon would be displayed).

(We are looking at how to change the user interface to take advantage of the display remaining after power loss, possibly our MCU can display a reason for power loss just as it is loosing power - all TBD).

Paul

[Charming]

Dear Paul,

We have such solution to give the EPD has the last gasp from the stored energy in super-capacitor to update the screen to a black (or defined pattern in code) image while power is lost. The circuit can be found below.
   

1. We used TI LaunchPad with our EPD extension board to connect with an EPD.
   
2. Press onboard Reset button to initial the code and run a normal update to show the first image.
   
3. Remove the battery suddenly. The ADC pin will recognize the BT1 is lost.
   
4. The remaining energy stored in the super capacitor will supply the MCU to update a preset black image. We used ultra low power mode of the MCU where the speed was 1MHz only to ensure a completed update and save power.
   
5. We chose a 30mF super capacitor. It proves that the circuit is workable. The video can be found on
   
   .
   

I hope this solution has answered your question.

Charming Su - FAE@PDi

[Paul@Port]

Quote: 

That looks like it will work to give us both choices (erase or final message)
Excellent
Thank you
Paul