User Tools

Site Tools


glossary:glossary_g

Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revisionPrevious revision
Next revision
Previous revision
glossary:glossary_g [2017/02/16 11:01] – [Ground] WortingUKglossary:glossary_g [2022/03/24 20:13] (current) – [GIT repository] Logically separate the tool from repositories chrisridd
Line 3: Line 3:
 [[start|Return to main Glossary index]] [[start|Return to main Glossary index]]
  
-===== GIT repository =====+===== Gerber =====
  
-GIT is one of group of publicly accessible repositories for softwarefirmware, and documentation which implement 'versioning' Versioning keeps track of changes to files and let'one follow those changes, revert to previous versions, and create branches so that varieties of the code can be madeand also merge branches back into the main branch +A Gerber is a 2D binary vector image that describes every single layer of the PCB design. For instance, one Gerber describes the silk screen while the other describes the topcopper layer. 
 + 
 +===== GIT repository =====
  
-Wiki entry: [[https://en.wikipedia.org/wiki/Git_%28software%29]]+Git is a popular version control system primarily used for managing software source code, but is also used for managing firmware, documentation... Versioning keeps track of changes to files and lets one follow those changes, revert to previous versions, create branches so that varieties of the code can be made, and also merge branches together again.
  
-SourceForge is another such web based versioning repository and should be familiar to MERG members as the home of JMRI: [[http://jmri.sourceforge.net]], +Git works using repositories, which can be entirely local on your computer, **or** linked to remote repositories on sites such as [[https://github.com|GitHub]], Gitlab, [[https://sourceforge.net|SourceForge]], and many others. [[https://github.com/MERG-DEV|MERG]] and [[https://github.com/JMRI|JMRI]] both use GitHub. Linking to remote repositories allows changes to be shared.
  
-The most popular web based Git repository is currently GitHub [[https://github.com]]; although there are plenty of other web, intranet and local based Git applications to choose from.+Wiki entry: [[wp>Git|Git Software]]
  
-Comparison between SourceForge vs GitHub: [[http://recomparison.com/comparisons/101554/sourceforge-vs-github/]]+[[http://recomparison.com/comparisons/101554/sourceforge-vs-github/|Comparison between SourceForge and GitHub]]
  
 To help understand how Git may be helpful to MERG here is a beginners article on GitHub: To help understand how Git may be helpful to MERG here is a beginners article on GitHub:
Line 21: Line 23:
 ===== GPIO ===== ===== GPIO =====
  
-General-purpose input/output is a generic pin on an integrated circuit or computer board whose behavior, including whether it is an input or output pin, is controllable by the user at run time+General-purpose input/output is a generic pin on an integrated circuit or computer board whose behavior, including whether it is an input or output pin, is controllable by a program or script being run. 
  
 GPIO pins (generally) have no predefined purpose, and go unused by default. Normally these are Tri-State pins. GPIO pins (generally) have no predefined purpose, and go unused by default. Normally these are Tri-State pins.
Line 40: Line 42:
 In modern 'mains' AC power supplies, the 'Earth' line has a safety purpose and the 'Neutral' line is the 'Live' current return. NB: The Neutral is connected to Earth, somewhere further back in the supply system. In modern 'mains' AC power supplies, the 'Earth' line has a safety purpose and the 'Neutral' line is the 'Live' current return. NB: The Neutral is connected to Earth, somewhere further back in the supply system.
  
-Most modern low voltage and low power electronic circuits are NOT referenced to the Earth, but the name Ground (aka GND) or Earth persists as the reference point, but more correctly its name is '0V'These power supplies are said to be 'floating'. Floating power supply modules can sometimes be identified by the use of a 2 wire connection to the mains.+Most modern low voltage and low power electronic circuits are NOT referenced to the Earth, but that name or Ground (aka GND) persists as the reference point, but more correctly its name is '0V'The power supply modules for these circuits are said to be 'floating'. Floating power supply modules can sometimes be identified by the use of a 2 wire connection to the mains. No harm will happen if the 0V line is connected to Ground.
  
-Above a certain threshold of Voltage or Power (or where a metal case/chassis is used), modern regulations mean that an Earth connection is required and those power supply modules will use a 3 wire connection to the mains. An example of this is the MERG DCC power block. +However, above a certain threshold of Voltage or Power or where a metal case/chassis is used, modern regulations mean that an Earth connection is required and those power supply modules will use a 3 wire connection to the mains. An example of this is the MERG DCC power block. 
  
glossary/glossary_g.1487242881.txt.gz · Last modified: 2017/02/16 11:01 (external edit)

Donate Powered by PHP Valid HTML5 Valid CSS Driven by DokuWiki