Last month, Jack and I went to a convention called “The Next HOPE,” where HOPE stands for Hackers On Planet Earth. I had a blast. In my day, hackers were just people who messed around with computers, but now the term has expanded to anyone who examines stuff, takes it apart to see what makes it tick, and creates Frankenstuff. I’ve always taken broken items apart; sometimes I fix them, sometimes I leave a mess of parts, but I always learn something. Imagine three thousand people who like to take stuff apart, taking over part of a large hotel for a weekend in New York City! That’s what HOPE was.
Actually, this HOPE wasn’t supposed to happen, as the Hotel Fithadelphia (not original to me, but I liked it as it perfectly described the Hotel Pennsylvania) was supposed to be torn down two years ago, after “The Last HOPE.” The developer is still trying to tear the place down and put up parking and offices, but the dirty old hotel is still running.
If you Google the hotel, you find lots of links to blogs describing in horrific detail the bedbug infestation that has plagued many rooms in recent years. We got lucky and got a room with new carpeting and mattresses - so new that the corners were not tacked down. On arrival, I pulled back the sheets to check the mattresses for bloodstains - a clue to an infestation - if previous guests were bitten, they leave small stains where the bedbugs thrust their piercing and sucking apparatus right through the mattress cover into their flesh - but the mattresses were pristine. From this, I assume the room had been effectively exterminated in the very recent past. I also looked in all of the nooks and crannies for the tiny insects. Finally, I checked myself out the next morning in the bathroom mirror and had no wounds. I think we were lucky.
The main rule at HOPE was, no messing with the hotel - which meant, primarily, no reprogramming the elevators, at least, not by the general membership. no matter how qualified.
The membership badge, hung on a lanyard around everyone's neck, was a circuit board into which you inserted a button battery. Once powered, a little red LED blinked regularly. Everyone quickly figured out that if you touched certain places on the badge in the right order, a white or a blue LED blinked, instead of the red one (these were hackers, after all, so we all immediately starting messing with the badge). The badge was an RFID sending device - there were readers all over the hotel so once you registered your badge, you could go to a big monitor and watch how people moved around the convention space. You could also purchase a small kit and “sniff” the datastream right from your badge in real time, if you had brought your laptop. I didn’t, but most did - and I bought the kit anyway.
To install the kit, you had to be able to solder a flatmount integrated circuit (a “chip”). It wasn’t easy. The chip was smaller than my thumbnail with 28 tiny legs, each leg separated from the next by a hair’s width. The Hackerspace had tables, soldering irons, and people selling various electronic kits. We bought the modification kits and settled into the Hackerspace. I had never soldered flatmount before, but figured it out quickly as I’ve built a LOT of devices (who do you think actually built all of the electronics that John designed for Ace Frehley’s lit guitars?). I taught Jack and Kirsten how to solder bigger components to give them practice before they tackled flatmount; they bought kits for various toys. In addition, there were electronic devices to dismantle and we had a grand old time, taking crap apart and putting stuff together.
Then, strangers started coming up and asking me to help them. I taught soldering for three days in the Hackerspace, whenever I wasn’t watching a panel - which added up to a LOT of hours! I made a lot of new friends. They plied me with beverages, including a vile drink that was popular at HOPE, “Club Mate.” I’m glad I tried it but it tastes like.... yuck. It is carbonated Yerba Mate tea, has a lot of caffeine, and is popular in Germany. As far as I am concerned, it can STAY in Germany!
Someone at HOPE started calling my method the Zen of Soldering. Soldering flatmount is substantially different from soldering larger components.
When you solder, don’t try to overpower your hands. Everyone shakes - you can’t help it as long as your heart is beating, so the soldering iron will also shake. The key is, find that perfect moment of stillness between your heartbeats to apply the iron to the delicate legs of a flatmount.
The steps for flatmount -
The circuit board is electroplated with solder, as are the legs of the chip, so you don’t need to add any more.
You DO need to add flux, which helps the solder flow smoothly. Someone at HOPE had a flux-marker, like a magic marker. It worked well. I think he got it at Radio Shack.
Place the chip onto the pads. Make sure the pin number one markers match. Nudge the chip gently to get it perfectly located, with the tiny legs centered on the pads.
Hold the chip in place with a finger on one hand as you apply the soldering iron to a single corner pin. You can see a metallic flash as the solder melts on the pad. It should take only a second or two (at most) with a hot iron.
Take the iron off without moving the chip. There will be another flash as the bright silver color of the liquid solder suddenly dulls to a solid.
Take your finger off and examine the chip carefully. Are you happy with its location? If not, tip the circuit board sideways and nudge the leg gently with the soldering iron, melting the solder and allowing the chip to fall off. Start over.
If the joint is good but the placement of the rest of the legs isn't perfect, you can nudge the chip with your finger into a better position without the necessity of disturbing the first joint.
Solder the opposite corner and examine again.
If you are happy, solder each remaining pin individually, a second or two per pin.
With a magnifying glass, examine the legs for bridges, which would cause a short-circuit. If you’ve been careful, your flatmount should be properly soldered. If you have a bridge, carefully heat the area and shake the excess solder off, being careful not to shake molten solder someplace worse! I usually smack the edge of the circuit board sharply on a table top to shake off excess solder.
Jack had never seen me in building electronics before. I’d built a radio-controlled model airplane to take photographs of archaeological sites when he was a toddler but I did all of the construction in the archaeology lab while he was in daycare. As far as he was concerned, I might as well have bought it. At HOPE, he was surprised to see me completely absorbed in building - either building my own toys, teaching others to build their own things, or building for them. He commented that he’s never seen me “geeked out” before. Indeed, he sometimes had trouble getting me to leave for meals! I’d forgotten what an integral part of my life electronics used to be. I hadn’t known how much I missed it and was thrilled to spend a weekend with like-minded people. Radio Shack, here I come!
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