One year ago today: July 20, 2014, home-made relay box.
Five years ago today: July 20, 2010, I want that tree.
Six years ago today: July 20, 2009, faster than a covered wagon.
MORNING
A late meeting of the club found us over at McDonald’s, going over plans to attend a house auction in Ft. Lauderdale, and on investing in air compressor parts. The club has been around so many years that you don’t even try to figure out how topics like this are related to robots. All that’s happened is most of the robot work has become routine and we can get distracted.
Come on now, what is the oldest situation in the human book? When others find out you have a tool, they suddenly require it. The tip-off is that they don’t need it tomorrow afternoon, or next Tuesday, they need right now and they are in their car on the way over. Notice how I mentioned no names, Agt. M?
All I am prepared to say is this pneumatic system, beginner’s level as I have set up here, is a winner. Wait, and you shall (undoubtedly) hear of the consequences of buying a decent air compressor. You may be the only one in your neighborhood who does more that just talk about it. I arbitrarily chose ¼ inch standard, which I think matches light duty spraying and grinding tools. I even spent six bucks on that coiled tubing meant for tools.
Have you seen the gang trying to latch on to any cause that lets them lambast Trump without actually admitting he is right about immigration? What a joke. The trick of stay back until the front-runner speaks a single controversial word, then jump on it. Like that anemic albino bald one, I don’t know names. But he is such a complacent ass, I would not buy him a beer over on Wiley Street. For that matter, anyone who serves in the military (rather than commands the military) makes that person a little too prone (or eager) to follow orders for my liking.
NOON
Of all the towns in Florida, Miami and Ft. Lauderdale share the one most common trait. They are a magnet for goofs and do-nothings. My plan for last afternoon was to find the new location of their foreign cinema and go see “Testament Of Youth”, published 1933. Back when women, as depicted here, wore funny hats and had no, you know, gloves. But the town conspired against me. The total plan was to find the theater an hour in advance, then go have a coffee and work the crossword until start time. Ah, but I had not factored in Ft. Lauderdale.
I drove back one. To hell with that, and I didn’t even tell you about the little things that went wrong. Like the scooter stalling in the heat, the lady who parked so I could not get out of my spot, and the SUVs that took turns tailgating me.
In the end, I wound up going to another McDonald's for that coffee. And once again, I seem to have got there on retard day. There is only one thing I dislike more than dealing with retards, and that is dealing with retards who have an aptitude for getting in the way. Since this was part and parcel of my upbringing, I'll never change. Equal, but separate.
NIGHT
This contraption is my S-wave detector. See addendum, but here is a rare sneak preview. The concept is, and you really have to look closely to see anything, a magnet inside the tube at which I point. That tube will be replaced by a finely wound copper coil. You may be able to make out a sample fishing weight, but it is nearly impossible to see the spring handing from the top mid-point of the isolation cage.
As usual, I will explain something this complicated twice, several hours apart. This, I find, to be a very effective teaching technique. This cluttered picture, which would not normally have made it past censorship, also shows the P-wave model behind and slightly to the right. And in the background, beside the signature lime-green gears, you see a beautiful 5V USB power supply. With a wag needle. When you see that, bet your money there is a robotics buff nearby.
Well, I did not go directly home, I stopped for a quiet beer and the crossword. Then I hear a familiar rasping voice and it is Carlos. Yep, New York Carlos, from the old neighborhood. He’s still a bass player, still looking for a band, and still working construction. And still wondering why I’d rather not live like that just to play in a rock band, that I prefer a smaller country duo that gets gigs.
Not having much to say about New York, I gather he is still driving the same old white van. The one full of spare parts for itself. I also ran into Wilfred, a guitar player who went to recording school. He’s said before he is not fussy about what he plays, as long as he can record it. So I bounced the idea of a country duo and he says he’ll send me a list of older tunes he would like to play.
But this is not the first time a guitar player has told me such tales. And he prefers, as they teach in school, to record each instrument repeatedly, seeking perfection. I prefer to record the whole band at once, on different instrument tracks. So the blending and balance is performed by the musicians, not a studio technician.
ADDENDUM
Before the original (and better) Hacktronics went under, they sent me a current sensor as a bonus. It sat until I decided to use it on my prototype S-wave (seismic) detector. The principle is easy to grasp. Our very first club experiment was to detect a voltage as a magnet passed through a copper coil. Ergo, where there is voltage, there is current. The magnet hangs on a weighted spring while the coil is firmly planted on the ground.
Ho, ho, not so easy. The current sensor is a complicated device. There is far more involved than connecting it to a circuit and reading the amperage. Why would a Millennial engineer design something that easy to use? It involves around five steps of conversion before you get a meaningful number. I suspect the intended purpose of this chip is for solar panel controllers.
It reads bidirectional volts from -30 to +30, therefore, a reading of zero appears as “512”. Only an Arduino coder sees the logic and beauty. I’ll break it down. The analog input pins of the Arduino are ten bit, and two to the tenth power is 1024. So halfway between your lowest and highest reading must be half of that. See the pattern? The largest “negative” voltage would read “0”, the highest “positive” flow reads “1024”, so zero is the half-way point.
But since most robotics works on five volts, your average is 2.5 volts. But digital is zero or five, never half-way. And way you go, trying to get this gizmo to work. This is about the time when you regret not paying attention in algebra class. So in reality, the chip is reading volts, not current. You have to zero it out, find the offset, and then convert that result to amperage according to a chart supplied in the documentation—which is on-line only. There is nothing included with the package. You must have Internet access to use this chip, in other words.
It took me four hours just to get a reading. I may stop at that until it detects something and then listen to the radio for the scale. Now you know why I am building only a detector, not a seismograph. Was there or was there not an earthquake is the best I can do for now. And that would be, to date, the most complicated and original programming I’ve ever done on the Arduino.
Last Laugh
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