I have recently learned a whole lot about CAT5 cables, ethernet and wi-fi since I've started working for a new company.  The reason the title says "be careful" is because you could fry your equipment if you inject it with to much power when it actually requires a lower amount of power There are different kinds of POE and this post will explain the differences between the passive PoE (Power Over Ethernet), the 802.3at IEEE standard and the 802.3af standard. Some background info The picture on the left is an extract from +IEEE 's website and it shows some of the other 802 standards ..read more

Some children playing in the house comes across an old typewriter and asks their dad to show them how it works.  The dad takes a sheet of paper and feeds it into the typewriter, sits down and starts typing. The kids are amazed! "Where do you plug it in, dad?" Dad smiles: "No, you don't plug it in." Their jaws drop with surprise: "Then where are the batteries!?" "It does not use any" the dad replies. "Oh, WOW Dad!  Then why hasn't anybody thought of this before!?" Now, there are still some of us who would remember learning to type on a typewriter.  The typewriter was a mechani ..read more

Some Linux background Although the latest versions of +Linux and +Ubuntu and others have GUIs (graphical user interfaces) where you can point and click with the mouse to navigate around the system and applications, the original UNIX system was run from CLI (command line interface). Why use the CLI? The advantage a CLI have over an GUI is that it is faster and more powerful, but the downside is that you have to know the commands and how to use them.  Some people may still remember using DOS and may be familiar with typing commands to operate your system, but these days most people operate ..read more

What is UBUNTU ... other than the Nguni term, roughly translated to English into "human kindness"? UBUNTU is the name given to the Linux based operating system and it is currently funded by +Mark Shuttleworth and +Canonical .  According to a 2012 online survey UBUNTU is the most popular Linux distribution on desktop and laptop PC's, but is also popular on servers and for cloud computing. What is Linux? Linux is an OPEN SOURCE operating  system.  Linux has been adopted for (ported to) more hardware platforms thank any other operating system and is typically used on big i ..read more

This is an amazing piece of work! The T8 from RobugTix ( +Robugtix  ) weighs 1.00kg and is about the size of an A4 sheet of paper.  Just watch the video and see how smooth its movements are.  And one of the amazing things about it, is that it is 3D printed!   It uses a total of 25 servo motors!  and it is powered by the BigFoottm Inverse Kinematics Engine. This Bigfoot Inverse Kinematic Engine is a black-box which does all the necessary calculations involved with the movement multi-legged robots like the T8.  It only needs to be given a command to move ..read more

This YouTube video was originally shared by MikeRobotScience which is +Michael Ettershank 's YouTube channel.  Michael's organisation (previously featured on +High-Tech SA - RobotScience) trains young South Africans about robotics and the RobotScience website has hours of instructional videos. Thank you for vising THE STEM BLOG SA Click on Subscribe, share (button below the post) or simply look me up on any of these networks:   Follow @weideJUR ..read more

The following AFRON (African Robotics Network) Challenge has come to my attention and I would like to share it with you: The Ultra Affordable Educational Robot Project 2013 Design Challenge: Robot Enhancements, Software, and Teaching Plans Sponsored by: The African Robotics Network (AFRON) and IEEE Robotics and Automation Society GoalThis project aims to collaboratively create an Ultra-Affordable Robot (an order of magnitude less expensive than existing products) to inspire young people around the world. In the 2013 Design Challeng ..read more

Holiday training program During the school break between the 2nd and 3rd terms there will be a training program taking place at UNISA aimed at +FIRST Lego League South Africa 's upcoming season launch at the end of August.  The dates/times for this program are 1 - 4 July, 09:00 - 15:00. The focus will be on: Robot building Robot programming and challenge solving  Participants of this program will be taking part in various fun activities and there are prizes to be won.                     ..read more

This post serves as an update to Robotics in South  Africa, and it is being written because the old post is becoming a bit tedious to read because of all the inserted updates I have added. So here follows a few of the organisations that I have found in South Africa who are actively involved with robotics training, robotics competitions, research and support.  Click on the pictures of each organisation to go to their respective websites. Robotics Association of South Africa Founded by +Andre Hoffmann and +Mike Barker and its objective is to "galvanises and coordinates the effor ..read more

This post forms part of my Line Following Robot project and will serve as my research for how to accurately control the speed and direction of the line follower. What is an h-bridge? This circuit is called an h-bridge because of it's construction - notice the capital H formed by the diode connections in the center of the diagram below (Thank you to Circuits Today for the diagram).  As you can see the elements used to drive the motor are two NPN and two PNP transistors, four diodes and four 1K ohm resistors.  To read more about the specifics of this circuit and its workings, click on ..read more