Søren Bøgeskov Nørgaard

Resistor Combination Calculator


I have created a tool for calculating combinations of two E12 resistors to obtain a desired value. This is useful when only E12 values are available. It can be found here.

Inline Assembly Functions in C for PIC18F Microcontrollers


I have been playing around with Assembly programming for Microchip PIC18F microcontrollers. I have figured out how to easily make inline functions in Assembly with the XC8 compiler. The results are shown here.

From Jemdoc to Jemdoc+MathJax


I changed my website from being generated by Jemdoc to being generated by Jemdox+MathJax. This means that I do not need LaTeX on my PC to generate formulas for the website. Simultaneously, Jemdoc+MathJax is compatible with Python 3 which is what I always use anyway, so now I only need one Python version on my PC.

I added the ability to center images with the img_center block. My version can be found on Github.

Changing the Clock Speed of the Lattice iCEblink40-HX1K


I have today fixed the jittering clock, I discovered on the Lattice FPGA board yesterday. I simply lowered the maximum clock speed to 25MHz by changing the set resistor on the board. See the results here.

Lattice iCEblink40-HX1K Clock Inaccuracy


I noticed that the clock frequency of the Lattice FPGA board changed when I did my designs. See why here.

Programming the Lattice iCEblink40-HX1K from Linux


Yesterday, I got the whole toolchain for a Lattice FPGA board working except for the actual programming of the part. Today, I found the tool icedude, which makes it possible to flash the board from Linux! This means that the board is now fully functional in Linux! Check out the guide here.

Lattice ICE40 FPGA on Linux


I just bought a Lattice FPGA evaluation board. I spent my weekend trying to get it working with Linux. I got far enough that a hex file was generated for the board based on my VHDL code but apparently, the programming functionality is only present in the Windows version. Bummer. In case I find a solution, I will update the web site. See the project here.

Moving Away From Github Pages


As I have gotten a dedicated server, I am moving away from Github Pages, where my web site was hosted before. This gives me more freedom to have dynamic content on the website.

Comparison of MP3-files at Different Bitrates


To decide on what format to keep my digital music in, I have added a visual, spectrogram comparison of some different bitrates. Check it out here.

Updated Power Supply on the RIAA


I added a voltage regulator the RIAA project because 100 Hz noise was introduced by the bad power brick I was using to supply it. New pictures and measurements were added to accommodate the update.

BJT RIAA Project added


I just designed a RIAA amplifier using a couple of transistors per channel. See the project here!

dsPIC33 Project: ADC to DAC loopback


I added a project where audio is looped from ADC input to DAC output on a dsPIC33. This can be the basis of small audio DSP projects, hopefully. Check it out!

Update of aauskema2text


I updated this script for the 9th semester at AAU/Wireless Communication Systems.

Note on Expectation and Standard Deviation of PSDs


I have added a note+script about determining expectation and standard deviation of an arbitrary power spectral density (PSD) or probability density function (PDF). This is done in the context of determining delay spread in wireless propagation.

Update of Math Notes


I found some un-clear things in some of the math notes. I have updated them now.

Kalman Filter Note


I added a note on implementing a Kalman filter. I have also included an example, implemented in python.

Update of aauskema2text


Updated aauskema2text to my fit 8th semester courses.

Upated Various Notes


Just updated some minor mistakes in some of the notes.

Updated aauskema2text


I just updated the script to fit the courses of Wireless Communication Systems masters, first semester.

Small Change to aauskema2text


There was a problem with detecting the Communication course so I made a small fix to the script.

Script aauskema2text Supports iCal Format


The perl script for downloading and displaying AAU's calendar in text format has been rewritten to support the new non-sict Moodle. The new script is on the scripts page.

HP50g Sequence Calculation Program


I just wrote a program for calculating sequences on a HP50g. Apparently, a program like this already exists on the HP (doh) but it may serve as an example of how to do a for loop on a HP50g. See here.

LTSpice to CSV


Have you ever been annoyed by the export format from LTSpice? It contains a lot of weird characters and is not easily parsed. I just added a script to convert it into a more normal CSV format. The script can be found in the scripts section.

Scripts Page


I just added some scripts that might be of use by AAU students.

  • One for plotting data from the frequency analyzer in the LAB.

  • One for parsing the Moodle course calender to a text table for the current week (for use with conky, for example).

Merry Christmas!

Notes -> papers


Today I have changed the title of the notes page to “Papers”. Hope this doesn't cause any problems :-).

Convolution on HP50g and HP49g


I just found a program online to calculate discrete convolution, like in my last note, on a HP50g calculator. I have shared it on my HP page.

Note on Discrete Time Convolution


One thing i've found to be very touch in mathematics is convolution and I never really got a grasp of it. Now I finally think I have it (at least the discrete time version) so now there is a note available here on the subject. Søren.

English Coding Standard for C


I just translated the C conding standard on the papers page to English, so that more people may be able to use it. I hope somebody can :)

Notes on Modeling and Control


I have made a new topic on the papers page called modeling and control. First note is about translational and rotational mechanical system (mass spring damper systems). Enjoy!

Various Notes and HP Calculator Programs


Today, I have added some notes as well as some HP calculator programs, that some might find interresting. I have also revisited the “About” seciton, so you can know a bit about me.

Also, I have chosen a bit larger font, to make it look like I have more content.

Some New Content


I have added a section in the menu containing some small programs etc. for the HP50g calculator i use. It will perhaps not be very well documented, but short things that may be able to help someone.

If something is unclear, or you have suggestions, please contact me :)