Monday, January 28, 2008

Solenoid Update

Just a quick update, I finished the solenoid lock...pretty much. It still has a logic error in the code I haven't yet fixed, which is even more pathetic given the fact that I'm a programmer by trade. I also want to bind up the wires a little better. It's a tad ugly, due to short sighted planning, but who cares, it's functional. I also made a much simpler version for testing midway through. I plan to put up details to it as well, since it's much more practical to make.

I'm moving my *sigh* Windows computer up there tomorrow so I can reprogram the chip. I'm getting a wireless PCI card so I can just leave it there.

Also I'm working on finishing up the little bit of wood-working for my workshop. The main part is Frankenbench(A simple sawhorse style bench I made that I've been slowly 'augmenting'), which I still need to:
  • Attach 2 more legs ( There will be 8 total ;)
  • Modify those new legs to hold more tools
  • Modify the underside to hold books better
  • Round the edges where I sit
  • Add some cushioning.
Hopefully by this weekend I can be done with both finishing my work area, and the solenoid lock writeup and can move on to my next project.

Thursday, January 24, 2008

Soldering &= Control Box Redux; // DC

Just repaired a crappy Western Digital(Although not as shit made as Maxtor) external hard drive, that happened to break itself when I was touching it. I refuse to say I broke it since the POS *never* had it's connections soldered for the USB plugin, instead it was a surface mount part that had 4 surrounding feet lightly soldered in place, on the main piece you repeatedly put force onto! I took the time to do it right(IE solder the actual connections), which was painful since the pins didn't stick out, they were instead underneath it, and that they were hair-pins. At least I learned alot from my repeated(It took me 6 tries till I was happy with it) attempts:
* It helps to place solder on the contact first then heat up the pin on top of the solder
* A light touch with the soldering tip, and then drag it along the contact seems to work the best
* A completely cleaned up soldering tip is the best thing at desoldering bridges between hair-pins

I also epoxied the fucker in place afterwards so it will never come loose again. Picture below, although there's nothing to see since the pins are in epoxy and underneath the actual plug-in:(UPDATE: The computer can't read the bastard, although I can hear it trying to spin, damnit)

Also I did take the effort/spend the $1 on spray paint to fix up my control box a little more for the solenoid lock. I did it outside on my balcony in a cardboard box, since I didn't want the neighbors seeing some random black electronic counter looking thing with wires sticking out sitting around ;)
Still not perfect due to the electrical tape covering the Dremel flaws I introduced by being to lazy to switch to a smaller cutting wheel, and the fact that it's crooked:

Last I never did put my pictures up of our latest downtown DC excursion for my family, so here they are(Barring anything with our faces):
Unsurprisingly only college aged kids were at the Colbert portrait, at least when we were there. We got there right at the opening of the Portrait Gallery(11:30) and there was a line within a few minutes in front of it.

Sunday, January 20, 2008

Solenoid lock -- Still not done

I was held up this weekend because we went to downtown D.C. on Saturday(Mainly to see the Colbert portrait). But did spend the majority of Sunday working on it. I had to redo the main control box since my homemade seven segment ended up looking like crap. I used a dual seven segment I had laying around, but it caused another issue: it draws more current and thus the relay doesn't have enough power to switch :( Right now I just added a 9V battery to the circuit to give it the extra juice, I will see if I have a better transformer laying around later.

Right now the control box is done, with all the parts soldered, hot glued, and epoxied in place. It turned out pretty crappy looks wise, but I wasn't expecting too much since it's made from junk lying around my workshop(A pen box to be exact), I may get a wild hair and spray paint it one solid color so it can't be seen through, but probably not:

Here's a better video of the circuit working than last time, basically I'm adjusting the trim-pot to display the hex-numbers, waiting till the input is accepted, then when the code(1B50) is complete the solenoid opens up(The C changes to O as well), when the user goes away from zero it closes and they can open it one more time by going back to zero before having to reinput the code(So the door can be closed):

What I have left to do:
* Solder up the microchip itself with a DB9 connector. I plan to hook up all the wires directly to the pins on the chip and then hot glue the entire mess to a piece of wood.
* Fix the logic bug in the microchip code, since I still haven't debugged the issue where an incorrect input is needed beforehand. I'm waiting till I solder the trim pot on, since it is loose and may be causing it's own problems.
* Mount all the components to the door, this includes: The solenoid, the metal the solenoid locks into, the microchip, the trim-pot, and running the wires.
* See if I have a power supply with enough power to run the relay and display

Sunday, January 13, 2008

General Project Info

I've decided that for larger projects I will start breaking them up into logical sections, then writing an overview and linking to the other sections from it. So for example on the solenoid lock it will be how the electronics were done, how the physical construction was done, followed by an overview of what it is and how it runs.

Right now I'm very close to the electronics being done for the solenoid lock. I have a bug in my code that makes it so an incorrect input has to be given before you can put in the password. Also the top light of my seven segment display died completely, I've decided to make my own jumbo sized 7 segment display with foam, which is close to being done already(Need to solder in and hot glue the actual lights).

I spent several hours Saturday trying to figure out how to use the NPN transistors correctly to power the relay. Turns out it had to be between the ground and not the power source, go figure.

I hope to get it completely done next weekend, but right now I think we're going to downtown DC on Saturday so I may not have enough time.

Picture of it on the breadboard, with really sloppy wiring:

Video of it running with the broken light, so it's kind of hard to tell what the numbers are. The test code is 1B50. Also apologies for the Happy playing, I forgot to turn it off and didn't feel like making another video:

Tuesday, January 08, 2008

Allelectronics Order

The rest of my ECE parts came from allelectronics today. Packaged just fine, no problems with anything I've tested. I got mainly LEDs, motors, connectors, and magnets. The only thing I guess I forgot to get was a lock switch...ohh well no biggie. The magnets are ridiculously strong, they can hold together through my hand, and I've taken to flipping them across the room towards the fridge. The super cap is cool, I made a quick circuit from my piezo tester from yesterday that will keep making irritating noises for about 5 minutes after the power is cut ;) The motors I got for my electric car have really tiny places to connect to...I have no clue how I will attach wheels, probably just use some epoxy and drill holes in a couple pennies.

Picture of all the new parts in my workshop:

Here's one of the solenoids hooked up. I just used four 9Vs to get enough power(Way over the 24V it's rated at), and hooked it to a little momentary switch. Will be kind of hard to make into a lock with how it works(Needs to be in a tad to start, but there is a place to mount an ending point), which I will overcome when I get to that project. Note that later I hooked the 9Vs up properly(In series not parallel) and was to the point that the switch would sizzle and produce visible sparks when pressed :-D Also the solenoid gets hot with repeated usage, regardless of voltage, which I already knew would happen with these(They were only $1 a piece):

Here's a video of me shooting it by releasing the momentary switch. I accidently put a small dent in my wall the first time I did this by accident: