The easy electronic paper comes for your Feather card, with this card that is designed to facilitate the addition of a three-color eInk screen. Chances are you've seen one of these new e-readers like the Kindle or the Nook. They have huge "static" electronic paper screens, which means that the image remains on the screen even when the power is completely turned off. The image is also highly contrasted and very readable in daylight. It really looks like printed paper!

We've loved these screens for a long time, and they're about the size of a Feather, so wouldn't a custom electronic paper FeatherWing make a lot of sense? This Wing is tested to work with all our Feathers, from the ESP8266 to the M0. It has an integrated buffer memory that allows it to work with chips as small as the'32u4 and'328. It uses many pins: the 3 SPI pins, and up to 4 control pins to manage the SD card and SRAM.

The FeatherWing has a 2.13" tricolor display (red, black and white). It has 212x104 pixels of black and red ink and a whitish background. Using our CircuitPython or Arduino libraries, you can create a frame buffer with the pixels you want to activate and then write it on the screen. Most simple cards leave it at that. But if you do the calculation, 212 x 104 pixels x 2 colors = 5.5 KB. This does not go into the memory of many microcontrollers. Damn it, even if you have 32KB of RAM, why waste 6KB?

We did you a favor and threw a little SRAM chip at your back. This chip shares the SPI port used by the eInk display, so you only need an additional pin. And, no more frame-buffering! You can use the SRAM to configure what you want to display, then mix the SRAM data with eInk when you are ready. The library we wrote does all the work for you, you can simply interface it with it as if it were an Adafruit_GFX compatible screen.

We even threw it on a MicroSD socket so you can store images, text files, anything you want to display. Comes assembled and tested with female connectors to which you can connect your Feather, no soldering required!

Technical details

Product dimensions: 61.3 mm x 40.4 mm x 40.4 mm x 6.7 mm / 2.4 in x 1.6 in x 0.3 in
Product weight : 14.2g / 0.5oz

Documentation

Librairie Adafruit_EPD