E-Ink low power daylight display

[bokakob]

REF: Waveshare 1280x825 9.7" display
https://www.dx.com/p/waveshare1200x825-9-7inch-e-ink-display-hat-for-raspberry-pi-it8951-controller-usb-spi-i80-i2c-interface-no-pi-2001597?tc=USD&ta=US&gclid=Cj0KCQiA14TjBRD_ARIsAOC mO9aJZG0vl_ZIeY5LtJxQ6lZ0EJXmJk_gqSNIznDW4eqszFin_ q4lXCAaAg3hEALw_wcB#.XGJL5BhOlky

I wonder if someone with more Raspberry Pi 3 B+ experience would comment. Based on specs it would be ideal OpenCPN display for bright sunlight for a small sailboat. At night a few LED's would give enough light to read the display.
Can someone please help? I can put things together, but I need some help and guidance.
Thanks.

[egilk]

Originally Posted by bokakob

I wonder if someone with more Raspberry Pi 3 B+ experience would comment. Based on specs it would be ideal OpenCPN display for bright sunlight for a small sailboat. At night a few LED's would give enough light to read the display.
Can someone please help? I can put things together, but I need some help and guidance.

In terms of power consumption for a full daylight display, E-ink is a really brilliant idea, as has been proven for e-books. I have some experience with E-ink, but not with OpenCPN. I believe there are some probable caveats:
* The display is black and white, with a few greys. Charts are typically meant to be presented in colour, so this makes the presentation problematic. Red and green would both appear as greys, for instance. For a vector based map I guess one could make special purpose legends optimized for B/W that would help a bit, but it is still a major issue.
* E-ink displays can typically only be fully rewritten. Depending on the technology, the entire screen will be erased every time there is a change in the display. During cruising, this will occur rather often.
* The refresh time is stated as less than 1 seconds, which I believe is actually quite slow, and would be very annoying. Some sort of limiter in the software probably needs to be added to ensure the display does not refresh continuously, rendering it unusable.

* Due to the slow dynamics, a touch interface would probably not work well. So it would have to be navigation by keypad only.


The display uses between 0.3 and 0.6 W. A Raspberry might use around 2.5W. I am working on a super-efficient LCD solution that uses 3W or less in sunlight, less when in the shadow. There is also an instant on/off for the display backlight, so you can easily turn it off if you are not using it. This solution might bring the average power consumption down to figures not too far away from an E-ink display.