Gemüsekuchen

Dieser Kuchen ist nicht zum Sattwerden gedacht, sondern zum Genuss bei Kaffee und Kuchen. Nur dass der Kuchen eben zur Abwechslung mal nicht süß und mit Obst ist, sondern eher deftig und mit Gemüse.

Cellphone Headset on PC or Mini Mixer

I own a Sennheiser HD429s mobile phone headset and a Behringer XENYX302USB mini mixer. I wanted to connect the headset to the PC via the mixer.

The headset has a 3.5mm TRRS plug where the tip, ring, ring, and sleeve are left headphone, right headphone, ground, and microphone, respectively.

The mixer is unlike almost any other mixer in that it has two 3.5mm TRS jacks for headphone out and microphone in just like a PC soundcard has. The headphone out tip, ring, and sleeve are left headphone, right headphone, and ground, respectively. The microphone TRS connector tip, ring and sleeve are microphone signal input, microphone bias voltage output, and ground, respectively.

The schematic for a headset adapter connecting the headset’s TRRS plug to the two PC TRS jacks looks as follows:

schematic of headset adapter

Melting Ice

Melting Ice

Melting piece of ice showing its non-homogenous structure.

Recipe for Vegetable Salad

The goal is to create a salad from raw vegetables which you can eat with a table spoon. Use this recipe forthe basic idea and adapt to your own preferences.

YUP LED With Send-echo-request

This is a sequel to the previous post on LED Configuration With OpenWRT, especially the part with the YUP LED (yield uplink please, i.e. “someone else is using the internet”).

To recap that previous post, I triggered one of the LEDs on my WRAP as a YUP LED with ICMP echo reply packets, which results in blinking patterns which let me read which other hosts are switched on. The ICMP echo replies arrive as replies to the packets sent by a bunch of ping processes.

Now I have written a new program send-echo-request to make the blinking pattern timing more precise and above all to avoid the race conditions caused by the two ping processes running in parallel.

Every 0.5s, send-echo-request sends an ICMP echo request to the two hosts which interest me, and the iptables rules then triggers the LED with a very short 0.1s flash for a reply from one host, and a much longer 0.4s one from the other host.

As the hosts on my local LAN reply within much less than 0.01s, the echo replies arrive practically in the same 0.5s pulse send-echo-request sends the echo requests in.

Colors

Colors

Starting AICCU on OpenWRT

OpenWRT have apparently removed the /etc/init.d/aiccu start script in order not to violate the SixXS terms of service regarding repeated and unattended tunnel setup.

However, I want to have the router try one tunnel setup after I have manually switched it on.

Now, in order to have aiccu successfully set up a tunnel, we will have to ensure a set of conditions is met when we run `aiccu start´.

  • IPv4 connectivity to tic.sixxs.net
  • IPv4 connectivity to my POP
  • local system time must be accurate

LED Configuration With OpenWRT

I still had an unused obsolete PCEngines WRAP.1C board lying around. I had never tried OpenWRT on x86 (back in the early to mid 2000s, my WRAP ran LEAF Bering uClibc).

So I set up a SixXS IPv6 tunnel endpoint on the WRAP, and while reading the OpenWRT documentation, I stumbled over the mentioning of LEDs. Turns out that OpenWRT can trigger some boards’ LEDs on a number of events - which let me configure two special purpose LEDs instead of the two unused-by-default in the WRAP’s array of 3 GPIO LEDs.