About

I'm a software consultant, drawing boxes and arrows and coding anything from Visual Cobol to Node.js.

This is a place for me to document things I learn the hard way and letting Google index it. Hopefully it helps someone else.

I also talk about my codplayer project: building a CD player out of a Raspberry Pi, some Python and a '60s Philips record player.

/Peter Liljenberg


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i3wm with Gnome on Ubuntu 16.04

After upgrading to Ubuntu 16.04 LTS my hybrid i3wm/Gnome session broke. gnome-panel didn’t show, screen saver didn’t work, and other weird things. Here’s how to make it work.

Posted on 05 August 2016.
til i3wm gnome ubuntu 16.04 really, what was wrong with .xinitrc?


Ubuntu release upgrade fails outside Unity

Today I learnt that upgrading from Ubuntu 14.04 LTS to Ubuntu 16.04 LTS doesn’t work outside non-standard desktop sessions (like my i3wm/gnome hybrid). I had to log out, and log back in to a vanilla Unity session to get the upgrade running.

Posted on 03 August 2016.
til ubuntu do-release-upgade disunity


VLAN roulette with dhcpd

Today I learnt that if you run a Linux box as a router with a bunch of VLANs sharing the underlying ethernet interface with untagged traffic, you should only let dhcpd listen to requests on the VLANs. Unless you’re a gambler, and enjoy wagering money on whether your devices on the VLANs will get a useable address or not.

Posted on 17 January 2016.
til dhcpd vlan overly complicated home network


LCD and IR support for codplayer

As soon as I had honed in on Raspberry Pi for the codplayer platform, I planned to add an LCD display and support for a regular IR remote control. In short, make codplayer behave like a CD player. This had to wait until the player itself was complete, and progress was then awfully slow once work started. Now it’s finally deployed in my living room stereo, so let’s have a look at the construction.

Posted on 03 October 2015.
codplayer gpio physical hacking hardware


Firefox's special favicon cache

Today I learned – while building this site, natch – that Firefox have a special cache for favicons, which the normal cache refreshing techniques doesn’t clear.

Posted on 02 October 2015.
til html firefox


Why codplayer?

If, in the year of 2013, you set out to put a lot of time and Python and some hardware into building a CD player rather than a streaming service you have some explaining to do.

Posted on 27 September 2015.
codplayer rationalisations retrofitting


Using i3wm (or any other wm) with Gnome

Today I learnt how to make i3wm, or indeed any other window manager capable of running shell commands, to work nicely with Gnome.

Posted on 03 May 2015.
til i3wm gnome what was wrong with .xinitrc?


Housing codplayer

The loose codplayer components look a bit messy, so I wanted a nice housing for codplayer. A Philips record player from 1966, bought in a thrift store and unlikely to work, seemed like a good donor.

Posted on 28 December 2014.
codplayer physical hacking retrofitting