Adafruit eInk Breakout Friend with 32KB

SRAM PRODUCT ID: 4224

Add some bi-stability to your life with an Adafruit EInk Breakout Friend - your

fun pal who's happy to lend a hand when you want to work with EInk/E-Paper

displays. Luckily for us, just about every small-medium size EInk display made

these days has a standard 24-pin connection. This breakout will add all the

power supply support circuitry and level shifting so you can attach your favorite

display (up to tri-color 4.2") and wire it up to your favorite development board.

Using our CircuitPython or Arduino libraries, you can create a 'frame buffer' with

what pixels you want to have activated and then write that out to the display.

Most simple breakouts leave it at that. But...just about all EInk displays are

write-only and many only let you update the full display (not partial update).

That means you have to buffer the full image you want to display, taking up

precious RAM.

The Eink Friend is much friendlier - it comes with 256 Kilobit (32 Kilobyte)

SRAM chip. That means you can control up to a 4.2" 300x400 tri-color display

(300*400 * 2 colors / 8 bits-per-byte = 30KB). This chip shares the SPI port the

eInk display uses, so you only need one extra pin. And, no more frame-

buffering! You can use the SRAM to set up whatever you want to display, then

shuffle data from SRAM to eInk when you're ready. The library we wrote does all