Author Archives: o-brane

Wolfram Language Introduction Certificate

I’ve been working to improve my Wolfram Language skills by taking the Wolfram U study group on the introduction to the Wolfram Language that is integral to Mathematica. The Study group ran four days a week in April 2020 and required passing four quizzes. Thanks to Wolfram for running the program.

Wolfram Certificate of Program Completion
Wolfram Certificate of Program Completion for the Daily Study Group on The Wolfram Language Introduction.

Introduction to Mathematica® for Physicists

Springer has made Introduction to Mathematica® for Physicists available for free on its website. The book uses Mathematica 9 to describe physics topics that include:

  • Trigonometric functions
  • Quantum Oscillators
  • Spherical Harmonics
  • Adding Angular Momenta in Quantum Mechanics
  • Quantum Nonlinear Oscillators
  • Riemann Curvature Tensors
  • Multi-ζ Functions
  • Geometric Optics
  • Cyclohexane configurations

Scratch e-book

The MagPi magazine has posted the e-book Learn to Code with Scratch . The e-book describes how to make simple games and applications on the Raspberry Pi. Scratch is a visual programming language developed at MIT to teach kids how to code. There is a web version of Scratch on the website too.

MagPi Learn to Code with Scratch e-book cover photo

Maker Fair 2015

I had a lot of fun at Maker Faire 2015 in Queens, NY  this year. There were more large corporate sponsors this year. Intel, Google, and Microsoft all had their own large tents setup. Google showed some boards used to develop Android Wear software. Intel showed Edison development boards that were compatible with Arduino and Seeed sensor kits. Microsoft demonstrated Windows 10 Internet of Things running on a Raspberry Pi 2. Arduino showed some new single board computers. Seeed had numerous interesting electronics kits for the BreagleBone Green, and showed Open Source phone hardware. The Google Aria project might take notice of this hardware. It’s minimal but easy to hack. There were a lot of 3D printers and drones at the Faire too. Check out my slide show for some photos of some of these items and more.

There were a lot of talks on the center stage and I was only able to see two of them. I hope that Maker Faire will stream them soon.

Adafruit 2.8in PiTFT Display Sketup 8 Model

A reader request a copy of my Adafruit 2.8 in Sketch Up 8 Model so I’m posting it here. It’s a very basic model with just essential components models as block in key locations. I needed to interpret dimension on the board layout and the datasheet for the display panel to make this module. The model turned out to approximate the actual PiTFT fairly well for my application so please check that it fits in all the right places for your application. Also, if you make it better, please post the updates.

Raspberry Pi Sketchup 3D models

I’m trying to make a case for my Raspberry Pi (RPi) with an Adafruit PiTFT 2.8 inch display and was modeling it in Sketchup 8.  I made a simple model of the PiTFT display and then started looking for some 3D Sketchup8 models of the RPi Model B with 512MB of memory from the Sketchup 3D Warehouse to save some time. Connectors between the RPi and the PiTFT display did not fit quite right. A few measurements showed that some of the parts and boards were the wrong size.  My list of models investigated so far is shown below.

  • Raspberry Pi – Model B Rev2 by Gandy file Raspberry-Pi—Model-B-Rev.skp: The GPIO pins are spaced incorrectly at 2.4 mm and should be spaced at 2.54 mm. The board length is 86 mm and should be 85 mm.

  • Raspberry Pi Rev 1 by Billmar file RaspberryPi_FN120401823.skp: The board size and GPIO pin spacing seems to be good. For the few things I measured, this is the most accurate model so far. As this is model is for Rev 1 of the board, it does not have the mounting holes I’m looking for.

  • raspberry pi 3d model B 512 by Clavis file RaspberryPi.skp: The board size measures 81.9 mm but should be 85 mm. The GPIO pin spacing is 2.4 mm and should be 2.54 mm.



Graphene FET Toy Physics Model

This graphene FET toy physics model is primarily based on the graphene physics described in the paper Electronic transport in two dimensional graphene by S. D. Sarma et. al. and from materials properties data found in a number of sources (see the Description tab for the details). I’d appreciate any comments on errors, problems, inaccuracies, or how to make this model better.

The IV Model tab allows you to selected the gate dielectric, dielectric thickness, mobility, gate voltage, phonon energy of the dielectric, drain-source voltage, drain-source length and width, and the resulting IV curve is plotted for these parameters.

The Performance Table tab shows a summary of the graphene FET performance based on the selected values on the IV Model tab.

The Materials Properties Tab shows the dielectric constant, breakdown voltage, and optical phonon energy for each gate dielectric that can be selected in the IV Model tab.