Month: May 2021

Joseph Johann von Littrow

Jovan Stosic May 23, 2021

Joseph Johann von Littrow (13 March 1781, Horšovský Týn (German: Bischofteinitz) – 30 November 1840, Vienna) was an Austrian astronomer. In 1837, he was ennobled with the title Joseph Johann Edler von Littrow. He was the father of Karl Ludwig Edler von Littrow and the mentor of the mathematician Nikolai Brashman. His work took him to Russia for a time, which is where his son who succeeded him was born.

He became director of the Vienna Observatory in 1819. He served in this position until his death in 1840. He created the only conformal retroazimuthal map projection, which is known as the Littrow projection. Littrow authored the widely read Wunder des Himmels (“Miracles of the Sky”), which was reprinted eight times by 1897.

Von Littrow is often associated with a proposal to dig a large circular canal in the Sahara desert and fill it with burning kerosene, thus communicating the fact of human intelligence to aliens who may be observing earth. However, Von Littrow’s connection with this scheme may be apocryphal.

The crater Littrow on the Moon is named in his honor.

He is the great-great-great-grandfather of Roman Catholic Cardinal Christoph Schönborn.

https://en.wikipedia.org/wiki/Joseph_Johann_von_Littrow

Joseph Johann von Littrow was last modified: May 23rd, 2021 by Jovan Stosic

Home Assistant Reverse Proxy with Apache

Jovan Stosic May 23, 2021

<VirtualHost *:443>

ServerName home.example.org

ProxyPreserveHost On

ProxyRequests off

ProxyPass /api/websocket ws://localhost:8123/api/websocket

ProxyPassReverse /api/websocket ws://localhost:8123/api/websocket

ProxyPass / http://localhost:8123/

ProxyPassReverse / http://localhost:8123/

RewriteEngine on

RewriteCond %{HTTP:Upgrade} =websocket [NC]

RewriteRule /(.*) ws://localhost:8123/$1 [P,L]

RewriteCond %{HTTP:Upgrade} !=websocket [NC] RewriteRule /(.*) http://localhost:8123/$1 [P,L]

</VirtualHost>

Source: Reverse Proxy with Apache – Community Guides – Home Assistant Community

Home Assistant Reverse Proxy with Apache was last modified: May 23rd, 2021 by Jovan Stosic

MQTT Testing – Home Assistant

Jovan Stosic May 15, 2021

The mosquitto broker package ships commandline tools (often as *-clients package) to send and receive MQTT messages. As an alternative have a look at hbmqtt_pub and hbmqtt_sub which are provided by HBMQTT. For sending test messages to a broker running on localhost check the example below:

mosquitto_pub -h 127.0.0.1 -t home-assistant/switch/1/on -m "Switch is ON"
Bash

Another way to send MQTT messages manually is to use the “MQTT” Integration in the frontend. Choose the “Configuration” tab, click “Integrations” and click the “Configure” option under the “MQTT” integration. Enter something similar to the example below into the “topic” field under “Publish a packet*.

home-assistant/switch/1/power
Bash

and in the Payload field

ON
Bash

In the “Listen to a topic” field, type # to see everything, or “home-assistant/switch/#” to just follow the published topic. Press “Start Listening” and then press “Publish”. The result should appear similar to the text below

Message 23 received on home-assistant/switch/1/power/stat/POWER at 12:16 PM:
ON
QoS: 0 - Retain: false
Message 22 received on home-assistant/switch/1/power/stat/RESULT at 12:16 PM:
{
    "POWER": "ON"
}
QoS: 0 - Retain: false
Bash

For reading all messages sent on the topic home-assistant to a broker running on localhost:

mosquitto_sub -h 127.0.0.1 -v -t "home-assistant/#"
Bash

Source: MQTT Testing – Home Assistant

MQTT Testing – Home Assistant was last modified: May 15th, 2021 by Jovan Stosic

GitHub – zachowj/hass-node-red: Companion Component for node-red-contrib-home-assistant-websocket to help integrate Node-RED with Home Assistant Core

Jovan Stosic May 15, 2021

Installation

This integration is available in HACS (Home Assistant Community Store)

  1. Using the tool of choice open the directory (folder) for your HA configuration (where you find configuration.yaml).
  2. If you do not have a custom_components directory (folder) there, you need to create it.
  3. In the custom_components directory (folder) create a new folder called nodered.
  4. Download all the files from the custom_components/nodered/ directory (folder) in this repository.
  5. Place the files you downloaded in the new directory (folder) you created.
  6. Restart Home Assistant
  7. Refresh your browser window (bug in HA where it doesn’t update the integration list after a reboot)
  8. In the HA UI go to “Configuration” -> “Integrations” click “+” and search for “Node-RED Companion”

Using your HA configuration directory (folder) as a starting point you should now also have this:

custom_components/nodered/translations/en.json
custom_components/nodered/__init__.py
custom_components/nodered/binary_sensor.py
custom_components/nodered/config_flow.py
custom_components/nodered/const.py
custom_components/nodered/discovery.py
custom_components/nodered/manifest.json
custom_components/nodered/sensor.py
custom_components/nodered/services.yaml
custom_components/nodered/switch.py
custom_components/nodered/websocket.py

Source: GitHub – zachowj/hass-node-red: Companion Component for node-red-contrib-home-assistant-websocket to help integrate Node-RED with Home Assistant Core

GitHub – zachowj/hass-node-red: Companion Component for node-red-contrib-home-assistant-websocket to help integrate Node-RED with Home Assistant Core was last modified: May 15th, 2021 by Jovan Stosic

Thomas J. Kelly (aerospace engineer)

Jovan Stosic May 13, 2021

Thomas Joseph Kelly (June 14, 1929 – March 23, 2002) was an American aerospace engineer. Kelly primarily worked on the Apollo Lunar Module, which earned him the name of “Father of the Lunar Module” from NASA.

Kelly led the team at Grumman that designed and built the Lunar Module (LM2 shown)

Kelly graduated from Cornell University in 1951, where he was a member of the Quill and Daggersociety. Afterwards, Kelly obtained his MS degree from Columbia University and Ph.D. from the Polytechnic Institute of Brooklyn.

Kelly was the project engineer, engineering manager and deputy program manager for Grumman Aircraft‘s Apollo Lunar Module (1962–1970). His 2001 book Moon Lander: How We Developed the Apollo Lunar Module documents the process of designing, building and flying the Lunar Module.

Tom Kelly and Owen Maynard(center) in the Spacecraft Analysis Room (SPAN) during the flight of Apollo 11

Kelly was portrayed by Matt Craven in the 1998 miniseries From the Earth to the Moon.

https://en.wikipedia.org/wiki/Thomas_J._Kelly_(aerospace_engineer)

Thomas J. Kelly (aerospace engineer) was last modified: May 13th, 2021 by Jovan Stosic

WireGuard

Jovan Stosic May 10, 2021

WireGuard is a communication protocol and free and open-source software that implements encrypted virtual private networks (VPNs), and was designed with the goals of ease of use, high speed performance, and low attack surface. It aims for better performance and more power-saving than the IPsec and OpenVPN tunneling protocols. The WireGuard protocol passes traffic over UDP.

In March 2020, the Linux version of the software reached a stable production release and was incorporated into the Linux 5.6 kernel, and backported to earlier Linux kernels in some Linux distributions. The Linux kernel components are licensed under the GNU General Public License(GPL) version 2; other implementations are under GPLv2 or other free/open-source licenses.

https://en.wikipedia.org/wiki/WireGuard

WireGuard was last modified: May 10th, 2021 by Jovan Stosic

#include – Arduino Reference

Jovan Stosic May 8, 2021

#include is used to include outside libraries in your sketch. This gives the programmer access to a large group of standard C libraries (groups of pre-made functions), and also libraries written especially for Arduino.

The main reference page for AVR C libraries (AVR is a reference to the Atmel chips on which the Arduino is based) is here.

Note that #include, similar to #define, has no semicolon terminator, and the compiler will yield cryptic error messages if you add one.

Syntax

#include <LibraryFile.h>
#include "LocalFile.h"

https://www.arduino.cc/reference/en/language/structure/further-syntax/include/

#include – Arduino Reference was last modified: May 8th, 2021 by Jovan Stosic