A
couple of months ago my neighbor Tracy recruited me as a judge for RoboExpo
2013. Tracy is a public school teacher and has been developing the robotics
curriculum for the New York City School system, is a part of the Mokindo Maker
Space, and happens to be my next-door neighbor. The Expo took place at the
United Nations Schools with kids from all over the city. What a blast. Working
with the kids and their robots was amazing.
After
the event I started thinking, and with some spontaneous input from my good friend
Charles, landed on an idea. Parents all over New York City are in a constant
search to find something to do with a gaggle of kids at the next party. I want
to work with them, I may entertain them along the way, but mostly I wanted them
to leave the party with a head full of ideas as much as a bag full of loot.
Bouncing
this idea off Tracy, we gave some thought to the types of projects I might
offer. I wanted to be able to cover a couple of different ages group, genders,
and learning styles. To that end, Toby Vann, the Maker Guy is now offering the
6 party activities for your next birthday party. Over the next 3 days I will be
posting information about each activities that fall into 3 basic groups; small
bots, blinky lights, and playful circuits.
Tomorrow we’ll talk about Small Bots, but as a
preview here’s an adorable girl telling me about her the brush bot critter she
just made during RoboExpo.
I got a little ahead of myself installing components on the new coiled light bracer. Rather tha test each component as I went, I installed a bunch of stuff at once, and then turned it on (circuit-wise it was a repeat so I felt a little too confident). It didn't work. Nothing. I didn't know where to start.
So I cut the board out unsoldered it, and started over, the right way. The short is in the switch bank I made to control the various states. I may take it appart and redo that part too, or I may got for a walk. Let's just say reaching through the coiled copper to do all of that soldering and unsoldering yesterday got a weensy bit old.
When I was working on the first light bracer I kept having the thought, "looks cool, but I wish you could see the light show from more angles than dead-on."
The coiled light bracer is the response. In this "movement study" you can begin to see why the x,y,z accelerometer will be interesting for mapping-out more 3D like effects.
Several months ago I started this blog with the high hopes of writing 365 posts in one year. But before reaching even fifty entries, I was done. Unlike most abandoned blogs that die a slow death due to lack of content, I conciously walked away from this one.
Let's call this a new beginning. There comes a point in your life when you realize that monsters don't exist, we create them. I needed to take a break. I needed to slay a monster or two.
The good news is I didn't stop making the entire time I was away. I'll try and pull some of the better projects and catch you up on what I've been making.
Every day I get one step closer to the flocking led light
effect I want for a roomed sized installation. Granted it started with step 1,
learn to solder competently, so there’s been a lot of steps in this process.
Over the weekend I assembled this rgb led 4x4x4 cube from
Seed Studios. Assembly took a couple of hours as there are solder points all
over those stick thin pcb’s. Seed’s Rainbowduino board that is an Arduino
compatible controller board runs the cube with a professional multiplexed LED
driver. Essentially an Arduino unit all hopped up for blinky lights.
Since assembling the unit I have been working through
software bugs. When I plug it into the usb port all of the requisite led’s
light up on the board and a single red led begins to blink in the cube. That’s
it. I've read on-line that several people have noted this same state when they got done
assembling and finally juiced it up. They seem to have been able to work
through their issues, so at least I feel like I’m on the right track.
Getting the Arduino IDE to talk to the board is the big
problem. There is no specific device called “rainbowduino”. I tried using the
Uno setting and all of the 328 compatible options (at Kip’s suggestion) to no
avail.
There are a couple of hardware problems that COULD still be
wrong. I took a 50/50 gamble on two resistors, wasn't sure which was the 10K. I
matched the colors in the example on-line. I essentially didn’t look them up to double check, but still think I got right. The other thing is there’s a switch that
allows the arduino unit to draw power directly from 3volt power source rather
than the usb, again I think I got that right.
I’ve set it aside for an hour or two, there are plenty less
vexing projects. Although I did promise to have it running by the weekend, so
an hour or two max, and then more poking.
One of the skills I'm working on in December is soldering. After a failed attempt at making a Minty boost, I opted for the far more beginner style project in the Times Square watch.
The watch come as a kit from Adafruit. The kit includes:
The components are solder through on the PCB. As usual the tutorials Adafruit provide on-line are a perfect step by step instruction for assembly. I inventoried the pieces got set-up with a third hand, and went to work. With the magnifying visor I recently acquired, what once was a dreaded job, actually became kinda fun. I could see what I was doing, I could sandwich the lead and the iron, and the gently melt a perfect hershey kiss of solder into the hole.
It almost seemed too easy.
The last step of assembling the watch is attaching the 8x8 led matrix. Aka the lights you see on the front. It comes as a square cube like object with 16 pins on the back that get soldered to the PCB... almost too easy. I had been following instructions, soldering in each component in turn just as I was told. To that point the components had all been arranged on one side of the PCB and soldered in on the other. When I got to this last step I sort of, well, didn't finish reading the instructions. It was obvious which way it went on. So I put it on and soldered in all 16 pins, quite tidily too I might add.
Then I started looking at my finished product. I realized, unlike the rest of the components, this one was supposed to have had its pins pressed through from the opposite side, and THEN get soldered to the board. All 16 solder points I had just made, while pretty, were wrong. I did not panick, I did not curse, I didn't really even stop.
I decided if this was going to teach me to solder than it may as well teach me to desolder too. At this point I had no expectation of saving this project and I was simply learning a skill. My "goal" was to remove the solder from the 16 points, flip the led matrix to the right side of the board, and solder it back in correctly.
Most of desoldering is using copper mesh (think paper towel) to drink up the lower melting point solder (think spilled glass of water) that's on the PCB (think time counter top with holes drilled into it for water to seep into). After poking at it for more than an hour, I was able to melt, sop-up, and free all 16 pins, still in tact!
I flipped it over, got the pins reinserted correctly, re-soldered it, put the battery in, and wham, hello world.
Two things I think made the desoldering job tolerable:
1) Magnification: the geeky head-set is not just for show. It's like being able to visit that tiny little city on the PCB. Do yourself a favor don't be afraid to magnify.
2) Enough heat: I had the iron set just a little over 410C for the non-lead solder I was using. Having that much heat and fine control was invaluable. Do not scrimp on a cheaper soldering iron. It pays for itself in frustration.
The most important thing I learned? There's no shame in desoldering. In fact it's a skill all unto itself. Plus, it can be done successfully.
One last thing, with all this new found proficiency; after working on it for another 30 or 40 minutes yesterday, I still haven't got that pesky piece of solder out of the minty PCB. I think I may give that first attempt up as a lost cause.