June 16, 2015

Yesteryear
One year ago today: June 16, 2014, Paul’s Case.
Five years ago today: June 16, 2010, boring guitar players.
Six years ago today: June 16, 2009, tow a trailer, you say?

MORNING
           Pat-B was right, I finally learned to play a lead break on the bass. I’ve faked it before, but this one (Travis Tritt’s “Here’s A Quarter”) stuck in my brain so long I finally and deliberately mapped it out on the bass. I’ve played lead on the bass before as fills and novelty riffs, but this time I set out to play the lead. So, he (Pat-B) was eventually right, it finally came to that. And I like it.

           This dowel gets top billing today because Home Depot is no longer always the cheapest place in town to buy building materials. Seriously, have you see the prices of their hardware lately? Most screws and bolts cost ten cents apiece, and it is common for a single project around here to require them by the hundreds. This half-inch dowel costs $1.49 at a specialty craft store. The same product at Home Depot is $1.79. Home Depot prices, for what I buy, have doubled in the past twelve months. Now back to music.
           Before anyone expects me to play the Blues, let me point out a few differences on the bass. First, bending strings is far more difficult and many times cannot be bent in the same direction as lead strings. Guitar patterns don’t work because there is no “offset” on the B string, but there are bass patterns that can fake these passages—but you have to memorize the fretboard. You can’t just anchor on one string and pattern from there like a guitarist.
           Bass soloing is further confined to a smaller area of the fretboard and double stops are pretty much limited to three options. Since I’ve always played thirds a lot, I’ve got a slight advantage there. How does it sound? Well, it sound good enough that I’m wondering if I might be on to something here. This is not Pastorius whacked-out frazzle-bass passages. It is more like Chet Atkins on the bass. All the regular bass notes are still there or faked so there is no loss of continuity.
           This fits well with my philosophy of guitar playing. You can play anything you want—as long as you don’t leave out anything that affects the rhythm parts you are supposed to be playing. All of which kept me busy right up till now, and I need a coffee.

NOON

           “Never listen to anybody telling you how honest they are.” –Texas wisdom

           I could not help noticing the parallels of my aircraft model to the development life cycle of military gear. When I get to the phases of testing and brainstorming, I find myself having the same overhead and other costs that make the news on Pentagon cost overruns. Understandably there could be all kinds of factors I’m not considering. Like my background in military history, or even my in-house accounting system. But at every turn of the practical parts, I’m continually catching myself reacting like the military-industrial complex. Neat.

           Here, for instance is the latest variation of the stick plane. The last modification of moving the full size hobby servo motors into the “bomb bay” can be seen just behind the power plug I’m reaching for. The engines are staggered, this visible one facing port and the other, which cannot be seen here, is facing starboard. What’s happening is they are being slated for replacement.
           Ah, just like the real deal. In this instance, they are too large, heavy, and powerful. If you look closely, above the aircraft landing wheel, sitting on the wing root, is a micro-servo. It is a better match in power and scale. That is, it is roughly the same size to scale as a power plant would be in a similar type of real aircraft.
           This also means another long session at the drawing board. My system of using strings run along the fuselage to operate the ailerons does not work so well in real life. That would work better if I had designed those first, but remember, this airframe model was slapped together on the spur of the moment to examine something utterly different. Strings also require screw eyes, which have also gone up 15 times in price. The tiny ones now coast 13 cents apiece.
           Good for you if you noticed the placement of the mini-breadboard on top of the cockpit. That is not the “brains” of the device. It is nothing but the distribution panel. All systems are electronic, so I decided a breadboard, which has a “chip canyon” down the center, was a logical construction for linking the signal busses with the actuators (hardware). All powered parts are electrical, so this panel is exposed and would never be placed in such a vulnerable position in the finished product.

NIGHT
           I was up until 1:46AM to reach the conclusion that I was wrong. I designed the control column badly because my solution was not intuitive. While anyone with aptitude could be trained to fly, it makes sense to keep it easy. This required nearly three hours in Panera next to some noisy Russian chess players who plainly considered (by the dozen) that their game was superior to whatever it was I was up to. And they let me know it every few minutes.
           What I learned was that the “knuckles” of the flight column should equal the same construction of the control column. Ergonomics? It’s that, or there is a disjoint between the pilot and the flight path. The steering column must have a totally different feel than an adaptation of an automobile-style two-dimensional “steering wheel”. You can’t just tweak a basic flat design. So, I learned two things for certain:

                      A) The pilot will relinquish control to his non-dominant hand.
                      B) At this point, you are on your own. Put on the old thinking cap.

           As a reward to those who read this long, I’ll provide the short account of why some of the digital pins on the Arduino are marked PWM (pulse width modulation) and some are not. Don’t bother with the book, you’ll just get a long-winded description of how it works and you only want to know why. First thing to understand is that the signal to the pin is serial. Second thing is that any pin can be sent this serial signal, hence, all pins can perform as a PWM as long as the signal is present.

           Like all computer chips, the Arduino can only do one thing at a time. Normally, the output signal is dependent on some kind of sensor reading. So imagine you used a non-PWM pin to set your motor spinning, but when your computer code goes to take the next sensor reading. Hey! The motor stops. There’s your answer, think it through. The pins marked PWM are latching pins. Once you set them active, they keep on active until they receive some reason to do otherwise.
           Shown here is the PWN designation on the Uno model. The tilde indicates a latching pin. They are 3, 5, 6, 9, 10, and 11. Note that by convention, the pin most often used is pin 9. I have no idea how this came to be. These appointed pins, once activated, stay activated.
           This is sometimes called HPWM for “hardware pulse code modulation”. The serial signal is controlled by one of the built-in timers rather than commands from the Arduino code. While it is mentioned in most Arduino manuals, it is not spelled out like I just did. For that matter, it is often worded so confusingly that it is nearly impossible to figure out what they are talking about. And with electronics, we’ve all seen that before.
           You are certainly welcome.

ADDENDUM
           Japanese commercial.
           (This is why I don't watch TV.)
           No exit
           (This guy again?)
           The Physics Girl
           (Am I the only one who notices she never allows any pictures of her full figure?
           Er, my only interest is because I, too, am a physicist.)


Last Laugh

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