Sunday, February 5, 2017

Some electronics fun...

Some electronics fun...  The photo at right (taken with my iPhone peering through a 2x magnifier) shows the current state of one of my projects (I have lots of projects!).  This is the beginning of a touch-activated switch that will go onto the new cabinetry being built for our new mud room.  The cabinetry will hide a three-way light switch for the mud room lights.  This project will let one of the cabinet's knobs take the place of that switch, by toggling the state of a relay each time the knob is briefly touched while the cabinet door is closed.

The stuff you see there is the regulated 5V power supply for the electronics, plus the touch sensor.  The little wire visible coming out from under the top of the vector board will connect to the knob.  The blue 20-turn potentiometer adjusts the sensitivity of the circuit.  The funny thing with a white cap below the potentiometer is a switch, for resetting the touch sensor chip if it gets stuck.  The chip is the tiny little black rectangle with six leads just above that blue potentiometer.  It's the smallest component of all – smaller than the quarter-watt resistors and absolutely dwarfed by the 0.47 microfarad capacitor (the green monster on the right side).

It's kind of mind-boggling for this old fart just how small this stuff has gotten.  I can still remember (not very fondly, actually) when I did all my electronic construction using lug strips and point-to-point wiring, most resistors I used were huge 5 or 10 watt things, and the active components were vacuum tubes with sockets an inch or more in diameter.  Things sure have gotten much smaller!

Much to my amazement, when I finished wiring all this stuff and fired it up, (a) there was no smoke in the air, and (b) it worked on the first try!

Model X update...

Model X update...  I just finished installing a software update.  This one promises to enable some more auto-driving functionality.  Though I read the release notes, it's still not entirely clear to me exactly what was just enabled.  Many of the release notes covered things that were released in the previous release, talking about them as though they were new.  Also, the same language is in there about “calibration” requiring potentially several days of driving before the features are actually enabled.  So ... all I really know is that I just installed an update.  I have no idea what it's going to do, or when. :)

Super bowl?

Super bowl?  Two readers emailed to ask why I haven't been commenting on the super bowl (or, as I like to call it, the “stupor bowl”) game that's happening today.  Obviously these two readers don't know me well.  For their benefit (as well as for my other readers who may not understand about me and sports):

I don't know anything about sports – I cannot even reliably identify which sport is being played in any particular game.  I don't know how the games are played, or what the rules are.  I don't watch or follow any sports.  I don't know the names of any sportsmen (or women).  I don't care about sports.  I don't have any favorite teams.  I don't “root” for any teams.  I don't even know the names of any teams.  I care about sports less than I care about the abundance of fleas in Irkutsk, less than Debbie cares about stray inductance in 5% carbon film resistors, but slightly more than I care about Hillary's career opportunities.

Just to be clear for the more obtuse: I will not be watching the super bowl game today.

Actually, the only reason I even knew it was today is because it showed up in the news that I read.