For the annual i&i-conference, I try to find a ’new’ gadget for speakers and board members. Last year we bought Inky Phats with a Raspberry Pi Zero W. To be used as interactive name badges. A great success! In this article, I’ll share 5 tips on using the display, and I’ll be discussing a few problems. Inky pHat is an e-paper display with a dedicated controller in the PCB. Plug and play! And big thanks for the excellent documentation @Pimoroni!
Inky pHat by Pimoroni is easy to use ‘phat’ A HAT is an extension for the Raspberry Pi platform. Hardware attached on top or HAT. With the sturdy HAT construction, there a three benefits;
- No soldering; plug it onto the Raspberry Pi.
- Robust mechanical design, it can handle a school environment.
- ‘Autoconfiguration,’ all the software is provided. Just attached and install. ‘Plug and play/pray.’
I am thrilled with the HAT-system. It just works, no tinkering and no failure with a faulty connection. The design can handle some rough handling (always be careful when handling hardware!), and with the software backend from the manufacture, it’s just a few commands in the CLI, and it works. Most of the times ;-)
Tip 1 how to update Raspberry Pi⌗
It’s always good to work with an updated Raspberry Pi. Sudo apt-get update, sudo apt-get upgrade. It will take some time when this is the first time you are using their commands. Keep in mind; these commands are going to be typed into the terminal or SSH. To keep things organized, I always end the update sessions with sudo apt-get autoclean. This removes all the no longer used files after an update.
Tip 2 Please use a stable power supply⌗
It sounds like a normal thing to do, right… but I found out the hard way that this needs some TCL. The Raspberry Pi was giving strange errors, rebooted, and shutdown for no apparent reason. The installation on the sd-card went corrupt, and I couldn’t find the problem. I swapped the card, reinstalled the OS on the card, and even swapped Raspberry Pis. And with some deduction, Sherlock would be proud; I discovered a faulty power supply to be the problem. Double-check the quality of the Micro USB cable! And be careful when installing the Inky pHat. The pins of the Raspberry Pi and Inky pHat need to be aligned. DO-NOT-FORCE.
Tip 3 How to install software with CLI⌗
The documentation by Pimoroni is excellent. Getting Started With Inky pHat is a great start. It helps with the correct commands for the CLI. Again, this display is a command-line interface only. It’s a quick installation with a few commandos. I’ve summarized the commands under this text block. The dollar ($) sign is a new line on the CLI. Keep in mind; this is a United Kindom based company. And over there, color is spelled with ‘ou.’ ;-).
$ curl https://get.pimoroni.com/inky | bash $ cd /home/pi/Pimoroni/inky/examples $ python name-badge.py --type "auto" --colour "red" --name "Ramon"
Tip 4 Automate the sh*t with CRON⌗
CRON is the automation tool in Linux. It’s ’easy’ to use. I had a few challenges when I wanted to automate the update of the display. CRON was for me. I never used it. This resource helped me a lot! I started with calling the python script directly from CRON. After a few failures, I found that CRON does understand .sh scripts. This is my .sh script. I called it phat.sh. Open a new file with nano phat.sh. Be in the root of your folders; cd is the command to return to the root. Exit nano with ctrl+x and save (!) the file. After saving, make the file executable. Type in the same folder as the phat.sh : chmod +x phat.sh
#!/bin/bash cd /home/pi/Pimoroni/inky/examples/phat/ python weather-phat.py --colour red
In the CRON tab, I added the following. The /10 executes the script every 10 minutes (starting at .0 every hour)—only between 8 and 22 hrs. The bash is used to run the script. Pay attention to the absolute path with a / at the beginning.
*/10 8-22 * * * * bash /home/pi/phat.sh
Tip 5 This works, what’s next?⌗
And how what? You have a mobile weather station. It runs from a power bank or even a dedicated battery. I’m going to install it on the fridge with a micro USB cable to provide power. With the 10-minute update cycle, the screen isn’t heavily used and will work for quite some time. Inky Phat is a fun display. The use cases are immense, and I am slowly figuring out what else I can build with it.