Monthly Archives: April 2019

Introduction to the SNAP protocol

IntroductionS.N.A.P. is a protocol for communication between several connected hosts. It provides:· addressing· flags· ack/nak request· error detection (different error detection methods available)It can be run over different media, including RS485. It is optimized for a small footprint (limited computing, memory resources), but scaleable depending upon your needs.Basically, if you want to connect several compute [...]

By | April 23rd, 2019|Development|Kommentare deaktiviert für Introduction to the SNAP protocol

Elektronik-Gehäuse & Platinenabmessungen Standards

Abmessungen Raspberry PiEin Raspberry Pi 3B+ hat, als Vergleich, die Abmessungen: 85 mm x 56 mm für die Basisplatine. (USB & LAN, sowie andere Stecker ragen teilweise über die Platine hinaus). Hutschiene / DIN-SchieneHutschiene: TS35, U-förmiges Profil. Standarisierte Befestigungsschiene für Gehäuse, Racks, Schaltschränke, u.s.w. Sie wird vielfach in der Industrie eingesetzt. Einer der ersten Einsatzzwecke [...]

By | April 20th, 2019|Raspberry Pi Blog|Kommentare deaktiviert für Elektronik-Gehäuse & Platinenabmessungen Standards

Packaging Python projects for Debian / Raspbian with dh-virtualenv

This article aims to explain some things to developers which don’t use Python a lot, and might struggle with some of the concepts otherwise.I highly recommend the lecture of the following article as an introduction to the concepts discussed here: is an official repository of software for the Python programming language. It includes libraries we [...]

By | April 19th, 2019|Development, Raspberry Pi Embedded Development|Kommentare deaktiviert für Packaging Python projects for Debian / Raspbian with dh-virtualenv

mongo_orm custom name for collection

mongo_orm will automatically determine the name for your collection by using the Module and Class name, and appending an “s”.In cases where you want to name your collection, you can simply do this:class PapiTest < Mongo::ORM::Document     collection_name "Buster"     field test : String end get "/" do     pt =     pt.test = "I want your sex"     [...]

By | April 17th, 2019|Crystal Language|Kommentare deaktiviert für mongo_orm custom name for collection

Avahi how to assign several .local names to same IP

In some situations you would like to access the same computer / IP using different .local names.This is possible using the Avahi daemon. The following is written for Ubuntu 18.04 Bionic Beaver.Install Avahiapt install avahi-daemon avahi-utilsAvahi automatically adds your computer’s hostname to the .local Domain. For instance, my computer is called morpheus. Therefore it will [...]

By | April 10th, 2019|Tips & tricks|Kommentare deaktiviert für Avahi how to assign several .local names to same IP

Creating a Raspbian repository

If you want to host your own Raspbian repository, this article is for you.A Raspbian repository consists of a special directory structure on a webserver. The files, including the packages, are all static – therefore this repository could also simply be hosted on an Amazon S3 instance, for example.The sources.list entry in Raspbian/etc/apt/sources.listdeb stretch [...]

By | April 3rd, 2019|Raspberry Pi Blog, Tips & tricks|Kommentare deaktiviert für Creating a Raspbian repository