Once again, I’ve let my blogging lapse due to the trials and tribulations of a busy life. It has been far too long since my last post. Other than being able to say I’m 1 class closer to getting my master’s degree, not too much is new. …only 7 more courses to go…
If there’s anything I’ve discovered in the last four months, it’s that as a mechanical engineer, I certainly did not get the background necessary during my undergraduate degree to fully understand all of the content involved in signal processing. While the course is meant to be a signal processing course in the context of being for mechanical engineers (AKA “For Dummies”) I found that to really understand the significance and theory behind concepts such as Discrete Fourier Analysis, Fast Fourier Transforms, Short Time Fourier Transforms, or Wavelet Transforms, a background in higher level mathematics, complex algebra and mathematical functions is really helpful.
What I struggled with in the course is the deeper understanding of what’s really happening with some of the concepts. Take for example the concept of convolution. This is the basis behind the short time Fourier Transform, because the mathematical definition of the short time Fourier Transform is understanding that in order to get a closer look at a signal time segment, we “convolute” the window function times the complex exponential with the original signal to get a windowed segment of a signal. This allows us to see the frequency contents of a smaller section and we can see how the signal contents change over time.
Don’t worry if absolutely none of the above made sense (in fact I sure some savvy engineer with a strong signal processing background could call me out on this. Please be kind 🙂 ) All I was trying to get at is while I can talk to it at a basic level, I still really don’t have a good understanding of what “convolution” in a mathematical sense is. There’s many, many resources online which will try to break down in layman’s terms what it is, but right now, while I can implement what I’ve learned into a nice Matlab script that will punch out a beautiful looking spectrogram of the frequency contents of a signal, I still struggle to understand the mathematics behind some of the concepts (I will say Daubechies wavelets made my head explode in this sense). In short, a couple higher level math courses would have been really helpful.
So now that I have a few months with a bit of extra time, what’s the plan?
During the last month, I built myself a nice little subfloor in the garage of the place I’m renting. What I found this last winter is that the absence of having a good place to skateboard was one of the few things that makes me really crabby and disgruntled in general. Since my garage doesn’t have the smoothest surface, I decided to build a little subfloor to skateboard on.
While I had planned on doing a write up on it, it’s actually really quite simple. You take a bunch of 2 x 4s, some OSB sheets, masonite sheets, and a whole crap load of screws, and basically build a frame from the 2x4s. Then you lay the OSB sheets on top, and then masonite on top of that.
I probably didn’t need nearly as much lumber as I used, but it’s nice and sturdy. It’s not perfect, you can tell where the 2 x 4 sections are separated as it creates a bit of a hump in the masonite. That being said, it works pretty well for my purposes.
The nice thing with this setup is now I have no excuse not to do some kind of skateboarding. Even if it’s only a couple of kick flips or 360 flips for 20 minutes at the end of the work day, I have a place to go. I’ve discovered that sometimes at the end of the work day, I either need something else to focus on or just some way to get rid of some of the pent up energy I get from sitting at a desk all day.
As I’ve constantly referred to in the past, I still do have plans to make my homebrew draft system (or “Keezer” as it’s referred to in the homebrew community). What I’m struggling with at the moment is figuring out exactly what I want. While I have a pretty good idea of the quantity of kegs, types of faucets, CO2 tank size, etc… I’m trying to figure out what kind of overall design I want. One style is the “collar” design, which is pretty easy to implement. You remove the freezer lid, take some 2 x 4 or 2 x 8 wood and create a square collar in between the lid and freezer, then drill holes to mount the faucets on the collar. An example is shown below.
The other style is known as a “coffin” keezer. In my opinion, this style looks a lot more refined and more like a bar setup, however it does come with some challenges. One is that you have to take a bunch more steps to ensure you have a low temperature difference between where the taps are and the bottom of the freezer. If you have a higher temperature at the taps than in the freezer, you end up with a lot of foam when you pour your beer. This equates to lost beer (not cool!). This usually means you need to insulate the coffin box really well and you need to wire a fan to move some air through the bottom of the freezer up to the coffin box to keep it cold.
Also, I know if I went this route, I’d want it to look polished and refined, more like a bar setup. This would probably mean more money put into materials to make it nice and a lot more construction work to make it look nice. If I’m going to go to all the trouble to construct a coffin style keezer, I want it to look nice as well.
So while that’s coming up at some point, I want to hash out exactly what I want to do with it before I start putting it together, as I don’t want to be changing my mind after I’ve started down a specific direction.
As per usual, it’s a balance figuring out what to do next as I only have so much money to work with. While I have a pretty good idea of what the keezer is going to cost, I am constantly trying to get over the fact that it costs a decent amount of money and jump in. We’re not talking thousands of dollars, but enough to stop and think. The usual questions of “maybe this money could be better used elsewhere” come up. Maybe I should buy the TV first while it’s on sale at Bestbuy. Maybe I should focus on paying off my truck. Maybe I should get a Tonneau cover for my truck. Maybe I should invest in the stock market.
What I constantly forget is that material possessions are not the basis for happiness. Money, possessions, and wealth do not equal happiness. So while it will cost some money up front for the keezer project, it’s the planning and execution that’s the fun part. Plus I know the end result will grant me many a good pint.
Photography, Electronics, and the rest of my life.
My photography has taken a bit of a back seat in the last couple of months. At some point I hope to get that back up and running as I still want to work on my time lapse rig that I spoke to in previous posts. It’s been quite a while since I’ve done anything with my Beaglebone Black, so if I look into that again, I’ll probably be starting from the beginning while I refresh my memory on how to program it and make it work.
As I go forward, I probably will find that it takes me longer than normal to get my projects up and running. I only have 4 months until classes start up again, so my goal is to make the best use of my time since once school starts, the posts will stop.