0x79 - a blog

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Category: Linux

Building dexed for Linux with Docker

Dexed is a FM Synth Plugin (https://github.com/asb2m10/dexed) offering a standalone version you can download from their git releases. Executing their pre-compiled binary on my Linux machine I got the following error:

~/Downloads/dexed-0.9.4.lnx % ./Dexed
[1]    29833 illegal hardware instruction (core dumped)  ./Dexed

Building Dexed from source solved the problem :)

This is a quick guide how to build it your self using docker.

Dockerfile

FROM debian:latest

RUN apt-get update
RUN apt-get install -y git freeglut3-dev g++ libasound2-dev libcurl4-openssl-dev build-essential\
                     libfreetype6-dev libjack-jackd2-dev libx11-dev libxcomposite-dev \
                     libxcursor-dev libxinerama-dev libxrandr-dev mesa-common-dev && apt-get clean

RUN git clone https …
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Raspberry Pi: Use volume keys on keyboard with triggerhappy

To use the volume keys on your keyboard on linux or with a raspberry pi in particular, you can use the triggerhappy package, which comes pre-installed with raspbian.

The trigger happy config has to be saved at `/etc/triggerhappy/triggers.d/*.conf. We first specify the key, followed by the corresponding action to take.

KEY_VOLUMEUP    1      /usr/bin/amixer -M set PCM 5%+
KEY_VOLUMEUP    2      /usr/bin/amixer -M set PCM 5%+
KEY_VOLUMEDOWN  1      /usr/bin/amixer -M set PCM 5%-
KEY_VOLUMEDOWN  2      /usr/bin/amixer -M set PCM 5%-
KEY_MIN_INTERESTING  1 /usr/bin/amixer set PCM 1+ toggle

Some …

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Raspberry Pi: No HDMI Signal after boot

If you are having trouble getting a signal on your monitor/TV from a Raspberry Pi no matter the settings in boot/config.txt it might be because of the experimental GL driver.

No matter the settings in /boot/config.txt i always got to a signal during boot, but "no signal" when the desktop was supposed to show up, or the monitor detected the wrong resolution (1080p@30Hz).

# uncomment to force a specific HDMI mode (this will force VGA)
hdmi_group=1
hdmi_mode=4

# uncomment to force a HDMI mode rather than DVI. This can make audio work in
# DMT …
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Routing all traffic through VPN: iptables

There are a couple of good tutorials on how to set up your own OpenVPN server (e.g. here, here, or here). To route all traffic through VPN, you need to set up some iptables on the server, which is also well documented. This post is about a problem i encountered that was not described anywhere: on every reboot of your machine the iptables are reset.

To solve this, you want to save your iptables to a file and load them on the startup of the network interfaces.

  1. Setup iptables as usual:

    iptables -t nat -A POSTROUTING -s 10.8 …
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Media Keys for Spotify Client on Ferora

Users of the lpf-spotify-client on fedora do not automatically have the media keys bound to the client. You can do that by sending dbus commands to the spotify process (dbus is already installed as a dependency of systemd)

Just bind the following commands to your media keys in system settings.

Play/Pause:

dbus-send --print-reply --dest=org.mpris.MediaPlayer2.spotify /org/mpris/MediaPlayer2 org.mpris.MediaPlayer2.Player.PlayPause

Stop:

dbus-send --print-reply --dest=org.mpris.MediaPlayer2.spotify /org/mpris/MediaPlayer2 org.mpris.MediaPlayer2.Player.Stop

Next:

dbus-send --print-reply --dest=org.mpris.MediaPlayer2.spotify /org/mpris/MediaPlayer2 org.mpris.MediaPlayer2.Player.Next

Previous …

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