Hacking Weighing Scale to Upload Weight to Plotly using Raspberry Pi

I have been interested in monitoring and keep track of my weight. In the past, I have used phone apps for this purpose, works OK but I was thinking of reading weight information using some microcontroller from my weighing scale and upload the data to an online database. That means that microcontroller should connect to Read More …

Controlling Newport 1918 Power Meter with Python

Optical power meters in-conjunction with a detector are used to measure power from a laser source or monochromatic output. At work, we use Newport 1918 power meter. This power meter comes with its own software. However, I was interested in controlling this instrument with python. I made a class for this instrument . If you are Read More …

Controlling SP2150i monochromator with Python/PyVisa

Monochromator is used in optics research where a narrow bandwidth of light is required to be illuminated on a sample. I work with Princeton Instruments Acton SP2150i and needed a python program to control it. I found the manual here and on page 9-10, I saw the serial commands for various functions (such as changing filters, moving Read More …

Installing Meep 1.2 on ubuntu

Pre-compiled Meep binaries for meep1.1 exist for Ubuntu distribution. This makes it very easy to install meep on ubuntu using “apt-get install” command or from the ubuntu software center. However recently, Meep developers have release meep1.2 which has more functions compared to meep1.1. I have recently installed meep1.2 from source on ubuntu 12.04 using the Read More …

Electric field at localized plasmon resonance using MEEP

This article is about simulating localized plasmon resonances in metal nanospheres using MEEP package. Generally, I am interested in solving three problems in LSPR systems: Calculate the extinction, scattering, absorption spectra of metal nanoparticle The procedure for doing this is very similar to the method I mentioned here. Calculating the electric field enhancement spatially as Read More …

Parallelization in Octave using parcellfun/pararrayfun

My computer has many processors and I would like to run some octave scripts so that all the processors are being used. One can use octave function called “pararrayfun” for this purpose. This function is part of “general” package on octave-forge. On my ubuntu 11.10, I used “sudo apt-get install octave-general” to install this package Read More …

van der Pauw correction factor

The van der Pauw Method is a technique commonly used to measure the Resistivity and the Hall Coefficient of a sample. A correction factor goes into calculating the resistivity as described in van der Pauw paper. A iterative method is generally used to calculate the correction factor and this correction factor is plotted in Figure Read More …