Lisp-Powered Laptop with a Battery Life Measured in Years

Re:Lisp-Powered Laptop with a Battery Life Measured in Years by kragen on Friday March 10, 2023 @04:43PM (#35101523)

Agreed. Also, my figures for eink power consumption are very uncertain; possibly you were able to take measurements or get good datasheets, but I couldn't.

A thing I didn't mention is that there are actually eink applications that have lower update rates than this. Store price tags, for example.

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Re:Lisp-Powered Laptop with a Battery Life Measured in Years by dragontamer on Friday March 10, 2023 @06:53PM (#35103056)

I decided to try my math again and document it more carefully.

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https://www.pervasivedisplays.com/wp-content/uploads/2021/12...

Pervasive Displays has an oscilloscope measurement of 3.75mA on their 5.9-second updates for their 1.54" eink screen. (Page 14). That's 22.125 mCoulombs of electrons.

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https://media.digikey.com/pdf/Data%20Sheets/Sharp%20PDFs/LS0...

Sharp 1.2" memory-LCD (a bit smaller) has 12uW to 50uW on static images. Assuming 3.3V, that's 15uA worst case (0.015mA).

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22.125 mCoulombs / 0.015mA == 1475 seconds per update break-even point, or ~24 minutes.

So yet another number, but yeah, memory-LCD is just really good. Remember that the 1.2" screen from Sharp is a bit smaller though, so its not a perfect apples-to-apples comparison.

Either way, its a much longer period between updates than I was expecting.

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Re:Lisp-Powered Laptop with a Battery Life Measured in Years by kragen on Friday March 10, 2023 @07:13PM (#35103282)

thank you very much! this is great!

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Re:Lisp-Powered Laptop with a Battery Life Measured in Years by Firmwarrior on Monday March 13, 2023 @12:15AM (#35130981)

Yeah man, thanks for this clarification, looks like I've been spending too much time tinkering with apps and I've gotten completely out of touch, haha

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