wvengen

OpenLabeler is a pretty nice image annotation package, but I had issues getting it to run. Plus I'd rather use the system-supplied Java environment, instead of a bundled one, and install it for a user (not in the system).

This happens on a Debian or Ubuntu system (with apt and deb tools available).

1. Download deb package of latest release.
2. Extract its contents: dpkg-deb -x ~/.local/openlabeler openlabeler-1.2.0.deb
3. Make sure you have OpenJDK 11 installed plus apt install libopenjdk-11-jre libopenjfx-java
4. Cleanup directory structure: cd ~/.local/openlabeler && mv opt/OpenLabeler/* . && rmdir opt/OpenLabeler opt

wvengen

• https://www.w3.org/2001/sw/sweo/public/UseCases/FAO/
• presentation on event in 2010
• Yummly food processor
• FOODpedia, linked data for food products
• Semantic web and GS1 (presentation)
• Example of how to use a semantic web of food
• OpenFoodFacts food product ontology notes, you can download a full products RDF dump
• Linked open data for halal food products - nice usage example

wvengen

#!/bin/sh
#
# Generates PDF from Publitas images (online folder service)
# Stores generated PDF and JSON (which may contains links).
#
# Requirements:
# - wget        https://www.gnu.org/software/wget/
# - jq          https://stedolan.github.io/jq/
# - imagemagick https://www.imagemagick.org/
#

wvengen

#!/usr/bin/env ruby
#
# Example of parsing a remote XML stream.
#
# Fetches data from an HTTP endpoint, and processes it bit by bit, without
# loading the whole file into memory.
#
# This example shows recent articles from the W3C blog feed.
#
require 'nokogiri'

wvengen

Freedrum on Linux

The recently released Freedrum has no official Linux support. But, fortunately, it uses standard Bluetooth LE MIDI. It doesn't seem to work out of the box, yet (on Ubuntu 17.04, most probably Ubuntu 18.04 will support it directly).

Bluez 5.46

One really needs bluez 5.46 or higher. On Ubuntu, these are packaged in artful proposed (amd64). Unfortunately, MIDI support is not enabled in this build (Ubuntu bug #1713017).

So you'll need to download the sources, install dependencies plus libasound2-dev, build and install resulting debs. You may need to add --enable-midi to debian/rules. Like this:

wvengen

#!/bin/sh
#
# Update freevpn.se pptp configuration
#
# Since the password changes now and then, it's useful to update it automatically.
# Make sure you've installed lynx. Tested on Debian.
#

URL=https://www.freevpn.se/accounts/
PEERNAME=freevpn.se

wvengen

#!/usr/bin/env python
#
# Export network-manager WiFi connection details to a wpa-supplicant
# file. This can be saved to an Android device, so you have all your
# laptop's WiFi connections on your phone right away (root required).
#
#    python gen_wpa_sup.py >foo
#    adb push foo /sdcard/foo
#    adb shell
#    su -c 'cat /sdcard/foo >>/data/misc/wifi/wpa_supplicant.conf'

wvengen

redux-api provides an easy and flexible way to interface with REST APIs in Redux (e.g. when building a React app). It works pretty well when there you know beforehand what API calls you're going to make, and define them in its configuration object.

But when you want to make multiple calls to the same endpoint, and don't know beforehand how many, you're a bit out of luck. In my case, I had a product listing where each product had a category and a score. In a summary overview, I wanted to show a histogram of the scores for each category. That means: first a request to the categories endpoint, and then for each of the categories, a request to the histogram endpoint.

This is an example of how to do that.

wvengen

The Raspberry Pi doesn't really have a proper audio interface. What options are available to give it one? This is a list o I2S-based Raspberry-Pi-compatible add-on boards (HATs) that also provide amplification, so you can directly connect at least two speakers.

• IQaudioIO's Pi-DigiAMP+
• Allo's Piano 2.1 HiFi DAC + Volt AMP
• LOCO DAC AMP
• Collybia's Mamboberry HiFi DAC + external amplifier
• HiFiBerry AMP+

wvengen

Basic redux-api sample

redux-api makes it easy to access REST APIs from a React+Redux app. This is a very basic example app showing its usage.

See it in action