Monday, October 19, 2009
Electronics for Intermedia Project 1
The first project: a prototype or working component of our final project, a practical electrical arduino project. It was supposed to have working multiple LEDS and a potentiometer and a switch. Mine only has the LEDs. I know how to wire the pot and I know what a switch looks like. I was really close to learning how to do those: when the TA got to me after more than an hour he had time to sit and ask what I needed help with and then the professor called me up to discuss my proposal. My proposal for this!
After going thrifting 2 seperate times and finding nothing I was nervous I'd have to use my old art briefcase, which I am using to store stationary and it is brown and has a map painted on it, just really not right for this project and already used for something. But Andy's dad John had this excellent, excellent samsonite briefcase from we guess the 1980s. It is so perfect. It's so well made, and in great condition, and it's the right size for me to actually use.
Here is the excellent interior. The left compartment holds a casette! The right compartment is the same size as the cassette one, so andy said "It's for the casette you need immediate access to!" and we laughed because what is on a cassette? Why would some need strong plastic walls and others be adequately protected by a strap? Then we thought it might be a floppy disk. I am actually old enough to have used a floppy disk, but only have a fuzzy memory of it. The top has a snappy part and they are not floppy.
Anyway! The samsonite is fantastic but it was made indestructable! I need a lot of holes for my leds. My prof suggested using a hammer and nail, which made a tiny divot but didn't make a hole. (I bet someone could make a hole in a samsonite briefcase, but I was working with a little electronics for intermedia hammer and...) So, I went to the woodshop! Which I love! I tried to find an awl but had to use a tiny drill bit, a corer.
Wait, no, I had to make little dents* with a nail and hammer, and then I could drill. Indestructible.
So here is the setup. The pot meter is just chilling in the corner because I planned to connect it up but ran out of time.
Here are the hands free devices for soldering, dancing because they are so happy I got everything to work. The middle LED looked bright when I plugged them in one by one to check them, but next to the other ones it looks dull. At least it's symmetrical. There is a lot of solder, heat shrink tubing, and hotglue keeping that thing together (I plan to really use this as a briefcase from now on, and it's due in 7 weeks so it has to hold up) so getting out that LED... and then soldering inside a briefcase... and I won't be able to heat shrink anything because it might melt the hot glue...
Look, a "schematic". Yellow is ground, red is power, 225 resistors... It's only 15 soldered joins which I think would take only 45 minutes if everything went smoothly and you didn't need heat shrink plastic. The worst is when an LED cracked and I had to un heat shrink plastic everything around it. The stuff is really tough, and in the process I crimped a wire really a lot and had to replace it as I was afraid it would snap... I don't think I will use any heat shrink stuff for my main led part, too time consuming. Did you know LEDs can crack? Mine got too close to the heat gun I was using to shrink plastic.
So this is what the hot glue looks like on the inside. Hot glue is a mess but my prof suggested epoxy and I wanted it a lot more reversible in case anything breaks. It was really hard to do because there is no real way to look straight and up close at this part of the briefcase.
And here is what the hot glue looks like on the outside. I am very good with hot glue, actually, and made little frosted bubbles so the LEDs wouldn't be exposed (they're recessed, but the drilled holes are rough and everything, I thought smooth bumps would be better than rough indents both visually and practically).
So now I just need an RFID reader and tags set up by the next due date in 2 weeks. (If you don't do computer things, LEDS are to RFID as crawling is to dancing. It is quite a near deadline.)
*Well, I am saying nail to save face, but in the intermedia lab I couldn't find one so I used a small thing, like a straight screwdriver, and in the woodshop I was embarrassed to ask where the nails were so I used a screw. I felt a bit silly using a hammer to nail a screw into a briefcase, but it worked.