Nixie Tube Thermometer
Successfully designed the PCB on Kicad! After a while it becomes quite easy to use! I ordered three samples from Oshpark and I hope I receive it soon. The most difficult part was modifying the footprint for the nixie tube (I'm using the IN-14s) to add four SMD pads to solder on a WS2812B LED to add a different color based on temperature! I added the ability to connect either a DHT22 sensor (both temperature and humidity) or a DS18B20 sensor. The reason for this is that the latter came with a long cable that I would be able to place in a different location as the main electronics. The other sensor will be used to measure the temperature of my dormitory.
The current list of things to do is write the program to control the nixie tubes, LEDs and temperature sensor.
This project will be a nixie tube based thermometer. At the present moment I have a basic schematic of the electronics; but I still have to make into a PCB that I then order. Then I have to write the script to control the tubes. I plan on using a multiplexer to control the 5 needed tubes with 3 GPIO pins from a Raspberry Pi.
Anyway, It's a work in progress.... Hope I can finish it during the summer, I get busy.
EEG Amplifier and Digitizer
I designed and build an EEG amplifier with the aim of being able to record myself during my sleep and be able to identify the different stages of sleep, in particular slow wave sleep (SWS), because it was associated with memory consolidation. To digitize it I wrote a C++ program that interfaces with the MCP3002 ADC and runs on the raspberry pi. I was able to collect at a sampling frequency of over 1kHz. Sadly, I ended up getting busy with the lab and didn't continue with the real-time analysis where I would detect fast spindle activity as it's happening in order to intervene with it. The paper that got me into neuroscience was published in April of 2013 and it used closed loop auditory stimulation to potentiate the length of these spindle events and improve memory consolidation as tested by a word recall test. Then by June of the same year I was working at Timothy Murphy's lab. Hope one day I can finish the real time analysis and play around with it.
3D Printed Telescope
I extracted the focusing lens of an old overhead projector that I found in the recycling room of my dormitory. I kept it on my shelf for a few months before I realized I could build a telescope with it.
Using the Autodesk I designed a housing for the lens that consisted of three parts. A dew/light shield at the tip of the lens, then a lens holder that clips the lens in between the lens holder and the dew shield. Finally a piece that attaches to the lens holder and is able to attach to a 1.25" eyepiece holder. I purchased the 1.25" on eBay since it was only 12$ and I found designing a rack and pin focusing mechanism slightly difficult with PLA plastic.
The lens has a focal length of 330mm! Sadly, it does suffer from a bit of chromatic aberration but it works very well!
I feel my website should be the first to be posted.
I wrote this website pretty much from scratch. I only used the Django web framework to develop the back-end and the front-end is written with a couple html templates and some simple css. I utilize SQLite for data storage. What I store are the entries to each of the pages. For example I have a projects table, a blogs table and publications table. Doing it in this way is extremely convenient, because it makes everything is easy to edit. I simply add a new entry in the admin page and it automatically updates on the website's front-end. The website took around a month to develop, since I had to learn some more of the inner workings of django and figure out a nice simple layout.
I'm really happy with the result.