Inkyphat HAT.........................
Les Pounder loves a good book and can be found reading on his e-ink enabled e-reader, but now he’s the able to create his own e-ink display!
Eink displays come to a Pi Zero near you, so Les Pounder paints the town black, white and red.
E-ink displays, typically those found inside Kindles, have been with us for over a decade. They offer a low-power method of displaying information, but the trade-off is a slow screen refresh. E-ink displays have been seen on the Raspberry Pi before, from Percheron Electronics and Pi Supply, but they were still only available as a two colour display (black and white.) But we now have a three colour e-ink display from Pimoroni: Inkyphat.
Inkyphat, as its name suggests, has been designed with the smaller Pi Zero HAT form factor in mind. It comes fully assembled, and connects to all 40 pins of the GPIO (general purpose input output). This means that it’ll work with all models of Raspberry Pi from B+ onwards. If you wish to use the board with an older Raspberry Pi then this is possible, because Inkyphat uses the SPI protocol to communicate with the Pi, but a GPIO header extension is required due to the older 26-pin GPIO being close to an AV output that blocks the board from a direct connection.
Inkyphat features a 212x104 pixel e-ink display capable of showing three colours at once (black, white and red) that are written to the screen as three individual refresh passes. Starting with the biggest refresh, black, then white and lastly red, the screen is updated based upon the size of the particles used in the e-ink screen technology.
Screen update times are slow, but this is to be expected for e-ink, where conserving power is more important than fast displays. The main benefit of e-ink displays is that they only consume power when they are being updated, so once it’s been refreshed the image will be there for many days but it should be noted that the red particles may “leak” over time and create a pink hue to the display. This is easily fixed by occasionally refreshing the screen.
Simple installation
To control Inkyphat a Python 2 and 3 library is installed using either a one-line installer (in the Terminal) or via a custom installer application. No matter how it’s installed, Inkyphat comes with many examples that illustrate how to use the library. From simple name badges, to weather stations and calendars, the e-ink display does a good job of displaying the information.
Using the Python library is simple, and a basic “Hello World” project can be created in just eight lines of code. It can also be used with other libraries and standard Python syntax, enabling Inkyphat to be used as an output device for projects such as a Twitter hashtag viewer, or as a newsflash device. Images can also be displayed on the screen, as long as they match the resolution of Inkyphat and have only three colours
As mentioned previously, Inkyphat has been designed with the Pi Zero in mind, and this is where it shines! The infamous conference name badge “Hi my name is…” is reborn as an interactive business card that shows how cutting edge you can be, and all of this is powered by an Inkyphat and a Pi Zero.
Inkyphat is a simple board. It works well as an output device and it’s adaptable enough to be used in many different Pi-powered projects. If you need a lower power display for a project, and you want it pHAT shaped, then this is the board for you. If you’re after a larger display and aren’t bothered about having a three-colour display, then Pi Supply’s Papirus may just meet your needs.
Inkyphat does what you need it to do and the Python library is easy to use. It may be a little more expensive than a typical pHAT board, but e-ink tech is still quite expensive despite being mainstream for the past decade.