Bogdan's Ramblings

I built a tool called Fono. It’s a voice front-end for your computer that can run entirely on your own machine. No cloud, no account, no audio leaving the laptop. It has three jobs, on two hotkeys:

If you’re a little bit like me, some subjects could seem too complicated. Other times you’d find it very hard to get started with something and keep procrastinating it. Or you might find yourself very tired to learn something new. And frankly, if we overcome all these we might find it was all in vain and we forgot most of it. Let’s fix this!

While searching for a hobby for my wife I got interested in photography. It seems that I am especially drawn towards low light photography which I understand is what “normal” photographers don’t usually do. I played a little with my phone in low light situations and even though it’s amazing where things are in 2019, it’s still not good enough for what I am looking for.

I am a DevOps consultant so I have access to a bunch of AWS accounts, in addition to my own. If I was to use individual credentials for each account, it would be very inconvenient especially since I have to switch between accounts multiple times a day. For a while now, AWS has a nice feature which allows me to access multiple accounts from my own AWS account. This feature is called Roles.

The Internet was made for Latin script, more specifically a-z, 0-9 and a hyphen. Of course, I’m talking about Internet addresses, which is exactly how you reach content online. The problem is that around 2 billion people actually use Chinese, Arabic, Devanagari, Cyrillic and other writing systems. Even the French, Germans and Romanians have non-latin characters so let’s see how those are handled online.

I did an impulse buy and got a Baghera Legend Red for my son and I decided to convert it from clean and boring pedal power to dirty and fun electric power. In this first part, I will do calculations and planning so I don’t order too many useless parts.

Whether you use a Mac or PC with Windows or Linux, your Intel computer runs some other operating systems in the background without bothering you with this piece of information. These OSs run all the time, have amazing capabilities and are impossible to remove.

If you have electronics as a hobby it’s unlikely you are going to get away without using a function generator. Its role is to make electrical waveforms over a range of frequencies while allowing to control the amplitude of the waveform. Some basic use cases include testing speakers or amplifiers, calculating inductance for coils or experimenting with resonant circuits such as for wireless energy transfer, induction heating or tesla coils. In some cases, I got away without spending a cent but at some point I got a 10$ kit and a while later I spent 50$ for a finished product. A “normal” generator starts from 300$ so what exactly is inside the 50$ one?

So, you know when you are tired or bored and you go to strange places online? I somehow found this flashlight online and from the picture, you can see many high power LEDs + many high power batteries + adequate cooling => awesome light output. The price at that time was ~50$ so I ordered because it seemed I get a lot for my money.

In the weekend I wanted to do something fun for improving the visibility of energy consumption. I ended up with a nice LED display that shows usage in realtime and some cool charts on my phone.

I got the perfect washing machine in my early 20s when I was single. It has some predefined programs, no display or any other complicated features. I was using mostly “power + quick wash”. Now, in my early 30s, my wife uses programs that take hours and staring them after work means the cycle would be done after midnight. So, let’s make that hunk of metal controllable from the Internet.

I wanted to give Selenium a try for a while and I just found the perfect pretext: earn enough votes in a SurveyMonkey poll to win a bottle of cognac.

Once in a while I compare the performance vs cost benefits of cloud vendors. In this case I just need to compare virtual machines, which is by far the most used service out there, so I guess sharing these results should be useful to many people.

Sometimes we need a negative voltage rail. There are several ways to obtain that but most likely the easiest is to use a charge-pump IC with only two capacitors. Because the datasheet doesn’t always paint a clear picture I decided to order a few and do my own testing for the things I care about (current, ripple, switching frequency).

Let’s see how to make a very precise clock that will be read with a large margin of error. It should be easy for the technically inclined and it can also be fun.