Tag Archives: papirus

Name Badge with the Raspberry Pi

For people who interact a lot with others, it helps to build relationships if there is a small gizmo available as a handout. Apart from being a conversation starter, this could also be an advertiser for that upcoming project or story. Most people relish being handed a freebie, and a programmable one-off gadget is one of the best.

These were the exact thoughts running through Rob Reilly’s mind when he got a tiny color LCD for Christmas. He conceived the idea of a programmable name badge, as that would certainly grab eyeballs. Being configurable, the message could change to a logo, or graphics as necessary, maybe even through sensor inputs. When you have an idea to sell, having a self-made project considerably adds to your credibility. What Rob Reilly did with an Arduino Pro Mini, Josh King has accomplished with a Raspberry Pi (RBPi) Zero. He calls it the PiE-Ink Name Badge.

For the necessary parts of the name badge project Josh starts with the RBPi Zero, the PaPiRus 2-inch e-ink HAT, an Arduino Powerboost 1000c, and a Li-Po battery. He puts the parts together using some magnets and adhesive putty.

After soldering the header pins to the RBPi Zero, Josh attached the Powerboost, which is a useful power supply. It has a built-in load-sharing battery charger that allows the project to run even when the batteries are charging. Any 3.7 V Li-Po battery can power this DC-DC converter board, which transforms the battery output to 5.2 VDC for powering the RBPi.

At this point, Josh attaches the PaPiRus HAT to the RBPi Zero, securing all the boards with putty, ensuring a snug fit. A mini slide switch in series with the power supply wires completes the assembly and allows on-off functionality.

Josh has Raspbian already pre-installed on the SD card, so he follows it up with the setup for the PaPiRus. He needs to download all the libraries in place for the RBPi Zero to recognize the 2-inch screen. To fit into the e-ink screen, Josh had to scale all images down to 200×96 pixels.

The PaPiRus is an RBPi HAT compliant design with an interchangeable screen size—you can use a 1.44”, a 2.0”, or a 2.7” e-ink display. It has 32 Mb Flash memory with a battery backed RTC, and the onboard EEPROM allows it to be plug and play with the RBPi. To facilitate projects, there is an onboard thermal watchdog, a temperature sensor, and a GPIO breakout connector with solder pads. There are four optional slim line switches on the top, and an optional reset pin header to allow the HAT wake on alarm from the RTC. PaPiRus is suitable for powering from 3.3 or 5 V power supplies, and compatible with RBPi, Arduino, Beaglebones, and many more boards that are similar.

PaPiRus uses the ePaper technology, mimicking the appearance of ink on paper. This technology is different from LCDs, as it reflects light just as ordinary paper does. Moreover, similar to ordinary paper, the ePaper display can hold text and images indefinitely, even without battery power being present.

As the display does not require any power to retain the image, the entire electronics could go to sleep for days together before the image starts to fade slowly.

Papirus E-HAT Supports Multiple Display Sizes on Raspberry Pi

You can transform regular paper into almost anything – write on it, make origami or even change it into paper-mache. Similarly, e-paper is also proving to be a platform for realizing incredible and versatile projects. E-paper has amazing properties such as excellent visibility, paper like readability and very low energy consumption. That makes e-paper a perfect platform for making phones, accessories and digital signs.

Pi Supply is now offering Papirus, a display HAT supporting e-paper displays up to 2.7-inches on the Raspberry Pi or RBPi Single Board Computer. Although another e-paper HAT is also available from Percheron Electronics, Papirus is priced lower than the Percheron e-paper HAT.

According to Pi Supply, Papirus is optimized for the RBPi Models A+, B+ and the RBPi 2 Model B. However, Papirus works well with any SBC running on 3.3 or 5V logic and power, provided the SBC includes I2C and SPI interfaces. Therefore, apart from the RBPi, you can use Papirus with Arduino, BeagleBone and possibly, the RBPi-Zero.

Similar to the Percheron e-paper HAT, Papirus also offers the three options of Pervasive Display. These options include displays of 1.44-in. 128×96 pixels, 2-in. 200X96 pixels and 2.7-in. 264X176 pixels. Papirus has optional slim-line switches.

The display on Papirus is supported by on-board 32Mbit flash memory. As the display is in the form of Hardware on Top or HAT, it has the necessary EEPROM to make it plug and play with the RBPi. A battery-backed RTC allows keeping real time. The on-board digital temperature sensor and thermal watchdog provide a safeguard against unnatural temperature excursions.

Papirus interfaces with the RBPi through its GPIO connector. Pi Supply offers users an optional GPIO breakout board and an optional reset pin header for a wake on alarm with RTC. Other optional offers are a pogo pin and four slim-line switches, which the user can solder on top of the board.

Currently, one can use Papirus with rePaper, the free software offering from Pervasive. Pi Supply is planning to add enhancements above the free offering. According to Pi Supply, this could be in the form of an Easy Installer and include example scripts, which will help to push the Raspbian desktop to the e-paper screen. Another possibility is the addition of a web application for remote screen management.

Functionally, E-paper is similar to ordinary paper. When jotting down something on ordinary paper, your pen leaves well-defined lines or text. Electronic paper displays give the same crispness and high-readability of their contents. However, the method of displaying contents on an e-paper display is different from that used by Liquid Crystal Displays.

E-paper uses e-ink technology for displaying its contents. Electronic paper display is actually made up of millions of capsules within a thin film. Each capsule contains a clear fluid in which there are several tiny particles of black and white colors and with different electric charges. On each capsule are two transparent electrodes on its top and bottom sides. Applying a positive or a negative electric field to an individual electrode makes particles with the corresponding charge move to either the top or the bottom of the capsule. The surface of the e-paper display on the capsule now appears to be either black or white.