I’m in the process of acquiring a telescope that has a motorized mount, and it requires a power supply capable of 12V, 1A. While it can be powered by 8 AA batteries, the actual output voltage of a bunch of batteries is not constant; It varies wildly from fully charged to fully discharged, which means […]
Nearly a decade ago, I wrote a post about building a serial adapter/cable for the FX-880P (and FX-850P) calculator. The design I went for was a bit over-engineered. The circuit was made of two independent parts on the same PCB; one that was a straight connection to the calculator via a 15×2, 1.27mm pitch header, […]
Tape recorders, computers and capture cards all seem to be happy to accept a microphone input for adding audio or voice-overs, but very few have a “line input” to overlay music or any other “strong” signal source instead.
It happens that I quite like scientific calculators, and lately I’ve been adding a few to my collection. Several calculators are CAS (“Computer Algebra System”)-capable, meaning they are powerful enough to do symbolic / algebraic processing, and thus are able to understand and manipulate algebraic expressions containing any mix of unknowns, operators and numbers, and […]
If you are using your Arduino’s PRNG (Pseudo-Random Number Generator) for anything more serious than flashing random lights for your Christmas decorations, there’s a chance you might run into some unexpected issues, as the random() function in Arduino seems to be somewhat broken. Why? Let me explain. Background Most basic random number generators in programming libraries and platforms are based on what is called […]
I have a very simple “audio/video” setup in my room. My main computer display doubles as my “TV” for playing videogames and watching movies. Technically speaking is just a 22″ HDTV with a bunch of input options, which I have connected to all of my devices, mostly through an HDMI hub, so I use the same screen […]