MobileRead Forums - View Single Post - The Open Book Project - Open source 4.2" e-ink e-book reader

binaryhermit · 01-26-2020, 05:55 AM

By my math, the screen is about 3.36 inches x 2.52 inches for a ppi of about 119 PPI?
That's... not great.
But it's powered by a freaking Arduino, so I suspect that may be more of a limitation of having very little CPU grunt and RAM
EDIT: As far as I can tell it uses an Adafruit Feather M4 Express which has a 120 MHz Cortex M4, 192 KB of RAM, and 512 KB flash

01-26-2020, 05:55 AM	#10
binaryhermit Grand Sorcerer Posts: 5,732 Karma: 20469902 Join Date: Oct 2014 Location: Lockport, IL Device: Kindle PW4, Kindle Paperwhite Signature Edition	By my math, the screen is about 3.36 inches x 2.52 inches for a ppi of about 119 PPI? That's... not great. But it's powered by a freaking Arduino, so I suspect that may be more of a limitation of having very little CPU grunt and RAM EDIT: As far as I can tell it uses an Adafruit Feather M4 Express which has a 120 MHz Cortex M4, 192 KB of RAM, and 512 KB flash Last edited by binaryhermit; 01-26-2020 at 06:04 AM.