Using finger service the wrong way

Tue, 31 May 2016 00:00:00 +0000

# Overview

If you’re doing this, you’re doing it wrong…:

2016-05-31 10:19:45.493314 Client 92.x.x.192 hamburg, germany/hamburg/hamburg
2016-05-31 10:19:48.443380 Client 74.x.x.189 greensboro, united_states/north_carolina/greensboro
2016-05-31 10:19:56.733260 Client 50.x.x.50 beaverton, united_states/oregon/beaverton
2016-05-31 10:19:56.745653 Client 50.x.x.50 beaverton, united_states/oregon/beaverton
2016-05-31 10:19:56.759656 Client 50.x.x.50 beaverton, united_states/oregon/beaverton
2016-05-31 10:19:56.819283 Client 50.x.x.50 beaverton, united_states/oregon/beaverton
2016-05-31 10:20:16.287744 Client 5.x.x.13 kaiserslautern, germany/rhineland-palatinate/kaiserslautern
2016-05-31 10:20:35.182942 Client 85.x.x.140 katowice, poland/silesia/katowice
2016-05-31 10:20:47.029550 Client 193.x.x.226 oslo, norway/oslo/oslo/oslo

Lots of people use the finger service @graph.no in an automated way. That’s quite alright, it’s what it’s there for. As an example:

But if you’re asking for the same data five times a second (until you get blocked by my firewall for a minute), you have to check your code. The data is at best changing every ~30 minutes.

A likely scenario is putting it in screen/tmux status line. If you do that, you need to change how often your terminal multiplexer is updating the status line. A better way is to have a cron script fetching the data, and storing it in i.e. /tmp/weather every 30-60 minutes, and then have your status line read from that.

Another scenario could be people running it in watch, which by default updates every two seconds. Also wrong. Please use -n 600 more.

If you fetch the data, and grep out what you need, then fetch the data once, and grep all you like. Don’t fetch for each grep. An example of this can be seen in the client graph.sh, which fetches the data, sed a lot and present it using unicode weather symbols and colors.

Feel free to contact me if you need scripts/examples or have questions.

Also, don’t feel ashamed, beaverton, you’re not alone in hammering me. I just don’t have any way to contact users. I still love you all. =)

photOS 2.0 - a better photo frame

Mon, 17 Feb 2014 00:00:00 +0000

# Overview

This is about improving photOS, mentioned in http://0p.no/2014/02/14/photos1.html.

When building this, price wasn’t a factor. If you want something cheap, you can still use this software with an old laptop or other recycled hardware.

The display from Chalkboard Electronics is beautiful. Good resolution (not extreme resolution, though), good contrast, nice colors. And it supplies power for the RPi. Unfortunately it’s hard to attach stuff to it. There are nothing but smooth surfaces.

All taped up to hide backlight. What you see is a rpi, a 4-port usb hub, a thumb drive (for keeping photos on) and the power board for the display.

Using some cardboard to keep everything together. Also makes for a decent foot.

Done and placed on the table. The photo doesn’t do the screen justice.

# Hardware

Raspberry Pi
10" Touch screen
Cover made of cardboard and tape.

# Software

photOS

# Features

Sync files from ownCloud, a free, selfhosted alternative to Dropbox.
Display local images in a slideshow.
Display images from web. I.e. webcams, weather reports, RSS feeds.
Display images from reddit, i.e. lates from r/newsporn, r/wallpapers, etc.
Stream video, i.e. from baby monitor, live webcams.
Display websites, i.e. news.
Display recent images (from ownCloud), by looking at date in Exif.
Turn off LCD at night.

Here is my current crontab, to show how I’m using it:

MAILTO=****
# m h  dom mon dow   command

PHOTOS=/home/pi/photOS

#Sync owncloud
#27 7-18 * * *  ${PHOTOS}/helpers/sync-owncloud.sh

#Morning
0 6 * * *       ${PHOTOS}/helpers/powersave.sh 1; ${PHOTOS}/web/weather.sh
0 7    * * *    ${PHOTOS}/web/website.sh "http://nrk.no/tekst-tv/100/"

#Normal photo display
0  9-16 * * *   ${PHOTOS}/helpers/kill.sh; ${PHOTOS}/photos/slideshow.sh

#Display weird images from the net
0 17 * * *      ${PHOTOS}/helpers/kill.sh; ${PHOTOS}/photos/slideshow.sh $( ${PHOTOS}/web/rss-images.sh 50 )

#Baby monitor streaming
0 19,21 * * *   ${PHOTOS}/helpers/kill.sh; $PHOTOS/streams/cvlc.sh http://192.168.1.84:8081

#Night
0 1 * * *       ${PHOTOS}/helpers/powersave.sh 0; ${PHOTOS}/helpers/kill.sh;

# Challenges

The screen has no attachments. I’ve currently just taped the RPi to the back, which works but isn’t very beautiful and will break down. See “Plans”.
LXDE, the default window manager on Raspbian, has no multitouch support. The image viewer, feh, has no gesture support. I’ve looked at a few ways to use touch, but hasn’t decided on anything yet. See this Reddit post.
Feh is somewhat lacking in rotating photos correctly.

# Plans

Use touch capabilities.
3d printed or CNCed enclosure.
Display photos related to this date. I.e. if christmas, display photos from past christmases.
Look for better image viewer.

Bash on falkp.no/blog

Using finger service the wrong way

# Overview

photOS 2.0 - a better photo frame

# Overview

# Hardware

# Software

# Features

# Challenges

# Plans