Today’s Saturday Morning Breakfast Cereal:
I liked the joke and am familiar enough with the math of working in unusual bases that I felt a need to implement a quick version of this in Python. Code follows.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 #!/usr/bin/env python def fourier(x, b): """Attempts to find a fourier version of x, working down from base b.
I was studying in Japan last semester (which explains somewhat why I haven’t posted anything interesting here in a while). That’s a whole different set of things to blog about, which I’ll get to at some point with any luck (maybe I’ll just force myself to write one post per day for a bit, even though these things tend to take at least a few hours to write..).
Background At any rate, back in Houghton I live with a few roommates in an apartment served by Charter internet service (which I believe is currently DOCSIS2). The performance tends to be quite good (it seems that the numbers that they quote for service speeds are guaranteed minimums, unlike most other ISPs), but I like to have complete control over my firewall and routing.
I updated the site’s SSL certificate to no longer be self-signed. This means that if you use the site over HTTPS, you won’t need to manually accept the certificate, since it is now signed by StartSSL. If you’re interested in doing similar, Ars Technica have a decent walk through the process (though they target nginx for configuration, which may not be useful to those running other web servers).
Rationale I was reading up on web frameworks available when programming in Haskell earlier today, and I liked the use of domain-specific languages (DSLs) within frameworks such as the routing syntax in Yesod. Compared to how routes are specified in Django (as a similar example that I’m already familiar with), the DSL is both easier to read (because it doesn’t need to be valid code in the hosting language) and faster (since it ends up getting compiled into the application as properly executable code).
A pattern I find myself using rather often in Python projects is to have a small module (usually called config) that encapsulates an INI-style configuration file.
I got a.. “fun” e-mail from mediafire a few weeks ago, saying that one of my files had been suspended due to suspected copyright infringement.
fb-hitler? Oh, that’s some Free Software I wrote. I disputed the claim, simply stating that fb-hitler.tar.bz2 is a piece of software that I created (and thus own the copyright to). As of tonight, I’ve heard nothing back about it, and the file is still inaccessible. Here’s the link to it, for future reference:
http://www.mediafire.com/?mhnmnjztyn3 (.tar.bz2, 477 KB)
And here’s the complete message I got. Notice it somehow got pulled in by somebody looking to get links to Dragonball Z downloads removed, and that the link to fb-hitler itself isn’t even in the (absurdly long) list of URLs given.
I caught on to a promotion from AVNet last week, in which one may get a free MAX5214 eval board (available through August 31), so hopped on it because really, why wouldn’t I turn down free hardware? I promptly forgot about it until today, when a box arrived from AVNet.
What’s on the board The board features four Maxim ICs:
MAX8510- small low-power LDO. Not terribly interesting. MAXQ622- 16-bit microcontroller with USB. I didn’t even know Maxim make microcontrollers! MAX5214- 14-bit SPI DAC. The most interesting part. MAX6133- precision 3V LDO (provides supply for the DAC) Board schematic Board, front side Board, back side The MAXQ622 micro (U2) is connected to a USB mini-B port for data, and USB also supplies power for the 5V rail.
Somebody had asked me about the schematics for my divergence meter project. All the design files are in the mercurial repository on Bitbucket, but here’s a high-resolution capture of the schematic for those unable or unwilling to use Eagle to view the schematic: dm-rev1.1.png. Be advised that this version of the schematic does not reflect the current design, as I have not updated it with a FET driver per my last post on this project.
On the actual project front, I haven’t been able to test the FET driver bodge yet. Maybe next weekend..
I got some time to work on the divergence meter project more, now that the new board revision is in. I assembled the boost converter portion of the circuit and plugged in a signal generator to see what sort of performance I can get out of it. The bad news: I was rather dumb in choosing a FET, so the one I have is fast, but can’t be driven fully on with my 3.3V MSP430. Good news is that with 5V PWM input to the FET, I was able to handily get 190V on the Nixie supply rail.
Looking at possible FET replacements, I discovered that my choice of part, the IRFD220, appears to be the only MOSFET that Mouser sell that’s available in a 4-pin DIP package.
I recently purchased a new laptop computer (a Lenovo Thinkpad T520), and wanted to configure it to dual-boot between Windows and Linux. Since this machine is to be used “on the go”, I also wanted to have full encryption of any operating systems on the device. My choices of tools for this are Truecrypt on the Windows side, and dm_crypt with LUKS on Linux. Mainly due to rather troublesome design on the Windows side of this setup, it was not as easy as I might have hoped. I did eventually get it working, however.
Admonishment Truecrypt was https://www.grc.com/misc/truecrypt/truecrypt.htm in 2014, but still works okay.
I recently pulled a few SDR (133 MHz) SO-DIMMs out of an old computer. They sat on my desk for a few days until I came up with a silly idea for something to do with them: rewrite the SPD information to make them only semi-functional- with incorrect timing information, the memory might work intermittently or not at all.
Background My sacrificial SO-DIMM Most reasonably modern memory modules have a small amount of onboard persistent memory to allow the host (eg your PC) to automatically configure it. This information is the Serial Presence Detect, or SPD, and it includes information on the type of memory, the timings it requires for correct operation, and some information about the manufacturer.