DFRobot e-ink display for Raspberry Pi

E-ink (or e-paper) displays have gained popularity as e-book readers have become widespread. They have found applications due to several of their features, which include: readability, energy efficiency and low profile. These advantages make “electronic paper” technology ideal for many amateur and hobby projects. Above all, projects powered by lithium-ion cells and other batteries. Below, we present a DFRobot display intended precisely for such applications

The monochromatic image on e-paper displays is created by manipulating (using electromagnetic signals) microscopic globules of colored substances. This means that the use does not see graphics thanks to optoelectronic light-emitting components (as in the case of LCD or OLED technology). The panel creates a physical image, similar to the one that is made on ordinary paper soaked with ink. In consequence: the human eye is not fatigued, and letters and shapes are perfectly visible even in full sunlight. Moreover: after disconnecting the power supply, the “pixels” remain in the same position as they were, so the image will be visible even if the display is switched off. In fact: power supply is only required for refreshing the screen. Of course, this minimizes the energy required to operate the display. This is why e-book readers can work for entire weeks without the need to charge batteries.

The DF-DFR0591 display is offered by DFRobot, which specializes in manufacturing modules for amateur, hobby applications, low-volume production and prototype construction. An e-ink panel with a 2.13” diagonal, buttons and all indispensable components were placed on a 66.5x31mm board. As one can notice, the size of the PCB nearly perfectly overlaps with that of a single-board Raspberry Pi Zero. Similarly with the signal link, which was made in a pin format, with a system of leads compatible with the GPIO port of many RPi models. The modules work with these computers in versions 2B+, Zero W, 3B+, 3B and 4.

Operating the display using Raspberry Pi computers is done using an SPI serial bus. After connecting the button leads situated next to the panel, they are shorted with pins GPIO29 (40) and GPIO28 (38). Next, it is enough to install free libraries made available by DFRobot. This makes it possible to control the display from the Python language level. The supplier has provided software with a series of practical functions for displaying text, drawing lines and shapes as well as bitmaps, and even for hardware support of the panel (e.g. image refreshing, clearing buffer). Thanks to these capabilities, the DF-DFR0591 module is ideal for facilitating the construction of individual projects and prototypes.

DFR0591 e-ink display