From a3e2611466f1ab0825bf38f135c36c5cfb29f5c4 Mon Sep 17 00:00:00 2001 From: Mitja Felicijan Date: Thu, 1 Jul 2021 22:22:56 +0200 Subject: Added new post - world clock --- posts/2021-06-26-simple-world-clock.md | 89 ++++++++++++++++++++++++++++++++++ 1 file changed, 89 insertions(+) create mode 100644 posts/2021-06-26-simple-world-clock.md (limited to 'posts/2021-06-26-simple-world-clock.md') diff --git a/posts/2021-06-26-simple-world-clock.md b/posts/2021-06-26-simple-world-clock.md new file mode 100644 index 0000000..29c199a --- /dev/null +++ b/posts/2021-06-26-simple-world-clock.md @@ -0,0 +1,89 @@ +--- +Title: Simple world clock with eInk display and Raspberry Pi Zero +Description: Simple world clockwith eInk display and Raspberry Pi Zero +Slug: simple-world-clock-with-eiink-display-and-raspberry-pi-zero +Listing: true +Created: 2021-06-26 +Tags: [] +--- + +Our team is spread across the world, from the USA all the way to Australia, so having some sort of world clock makes sense. + +Currently, I am using an extension for Gnome called [Timezone extension](https://extensions.gnome.org/extension/2657/timezones-extension/), and it serves the purpose quite well. + +But I also have a bunch of electronics that I bought through the time, and I am not using any of them, and it's time to stop hording this stuff and use it in a project. + +A while ago I bought a small eInk display [Inky pHAT](https://shop.pimoroni.com/products/inky-phat?variant=12549254217811) and I have a bunch of [Raspberry Pi's Zero](https://www.raspberrypi.org/products/raspberry-pi-zero/) lying around that I really need to use. + +![Inky pHAT, Raspberry Pi Zero](/assets/world-clock/hardware.jpg) + +Since the Inky [Inky pHAT](https://shop.pimoroni.com/products/inky-phat?variant=12549254217811) is essentially a HAT, it can easily be added on top of the [Raspberry Pi Zero](https://www.raspberrypi.org/products/raspberry-pi-zero/). + +First, I installed the necessary software on Raspberry Pi with `pip3 install inky`. + +And then I created a file `clock.py` in home directory `/home/pi`. + +```python +#!/usr/bin/env python +# -*- coding: utf-8 -*- + +import sys +import os +from inky.auto import auto +from PIL import Image, ImageFont, ImageDraw +from font_fredoka_one import FredokaOne + +clocks = [ + 'America/New_York', + 'Europe/Ljubljana', + 'Australia/Brisbane', +] + +board = auto() +board.set_border(board.WHITE) +board.rotation = 90 + +img = Image.new('P', (board.WIDTH, board.HEIGHT)) +draw = ImageDraw.Draw(img) + +big_font = ImageFont.truetype(FredokaOne, 18) +small_font = ImageFont.truetype(FredokaOne, 13) + +x = board.WIDTH / 3 +y = board.HEIGHT / 3 + +idx = 1 +for clock in clocks: + ctime = os.popen('TZ="{}" date +"%a,%H:%M"'.format(clock)) + ctime = ctime.read().strip().split(',') + city = clock.split('/')[1].replace('_', ' ') + + draw.text((15, (idx*y)-y+10), city, fill=board.BLACK, font=small_font) + draw.text((110, (idx*y)-y+7), str(ctime[0]), fill=board.BLACK, font=big_font) + draw.text((155, (idx*y)-y+7), str(ctime[1]), fill=board.BLACK, font=big_font) + + idx += 1 + +board.set_image(img) +board.show() +``` + +And because eInk displays are rather slow to refresh and the clock requires refreshing only once a minute, this can be done through cronjob. + +Before we add this job to cron we need to make `clock.py` executable with `chmod +x clock.py`. + +Then we add a cronjob with `crontab -e`. + +``` +* * * * * /home/pi/clock.py +``` + +So, we end up with a result like this. + +![World Clock](/assets/world-clock/world-clock.jpg) + +And for the enclosure that can be 3D printed, but I haven't yet something like this can be used. + + + +You can download my [STL file for the enclosure here](/assets/world-clock/enclosure.stl), but make sure that dimensions make sense and also opening for USB port should be added or just use a drill and some hot glue to make it stick in the enclosure. -- cgit v1.2.3