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5116  Forum 2005-2010 (read only) / Bar Sport / Re: Ordering basic stuff - what should I get? on: January 10, 2011, 07:02:43 pm
2n2222a Transistors - already on my list

If you plan on doing anything with DC motors, or anything else that might need an h-bridge (or you want to learn about h-bridges), get the complement (PNP) of the 2n2222 as Ran mentioned (2n3906) as well.

Also - you might want to buy one or two L293 or L298 h-bridge ICs (note that the L298 can -not- be plugged into a breadboard or perfboard as-is - but it does have a higher current rating than the L293 and can be bridged as well - there are people and places online that sell adaptor PCBs). Once again (and especially with these parts, as they can eat into your budget) only buy these if you think you will be doing projects with DC motors (and even then, you might want to wait); I don't consider them expensive parts, but I don't know your budget, either.

Finally - you might want to think about (and perhaps purchase) something for storage of your parts. I always reccommend Stack-On multi-drawer bins, but they are fairly expensive, and you need the room for them, and they may not be ideal for your "workbench".

Another idea, though, that is fairly cheap and great for someone starting out (or someone needing portability), is a multi-tray fishing tackle box. The multiple fold/fan out trays are perfect for holding a multitude of small, easily scrambled-up parts (since that is what they are designed to help prevent), and there are generally compartments to allow you enough room for a small multimeter, a soldering iron, and some solder (and other "larger" items).

Just something to keep in mind...

5117  Forum 2005-2010 (read only) / Bar Sport / Re: Your last purchase? on: January 10, 2011, 03:36:38 pm
Thansen: How'd you score such a nice board for free? If I wasn't already set up for the mini-ITX board in my project, I would love to have something like that (not that I need to reduce weight or anything, but smaller is always better on a UGV just for vibration sake).

Great find, though - however you did it!

5118  Forum 2005-2010 (read only) / Bar Sport / Re: Your last purchase? on: January 08, 2011, 07:45:36 pm
Picked up another big batch of surplus parts from Apache Reclamation today:

  * some Figaro gas sensors (not sure what kind, I have an email in to Figaro)
  * several motors (DC, one stepper)
  * a couple of 12VDC fluid pumps
  * some heatsinks (for some reason, finding nice multiwatt-15 heatsinks isn't easy; the closest I came was some expensive beast from SparkFun, and something from Digikey - found ones at ARE for 15 cents each)
  * some MJ12005 NPN power transistors
  * a bunch of TO-3 insulators (plastic and mica - at least 200 or so)
  * LM350K TO-3 3A adjustable voltage regulators
  * a 555 (it looked lonely)
  * a Motorola RTL JK flip-flop (still in-package!) for my antique collection
  * some microswitches
  * some trapped-ball tilt switches

Plus a variety of 74xxx parts (most LS):

  * 74LS245
  * 74LS253
  * 74HC943 (woohoo - 300 baud modem!)
  * 74LS168
  * 74LS14
  * LM337
  * LM565
  * ADG412BN

All-in-all, some fun stuff; the motors were kinda on the more expensive side of things ($10.00 each for some), but the components were only about $1.00 each on average. Plus there were a few "gives" (like the gas sensors). It was a good day.

Oh - and I went to Goodwill and got a small New Bright R/C truck ($3.00), and two ATA100 3.5" removable drive docks ($3.00 each - still in shrink wrap).


/I've got problems... ;D
5119  Forum 2005-2010 (read only) / Bar Sport / Re: Your last purchase? on: December 28, 2010, 09:31:33 pm
With the new firmware there are password protection, but only way to see the images is then to log in.

Do they leave a way to bypass this with the new firmware, so that you get the better stability of the new firmware, with the ability to run it "wide open"? I need to basically have it wide open to stream the data from the cameras to (ultimately) OpenCV for processing it (I imagine I could use curl or something to log in for me, but that's just an extra step that isn't needed - I don't need the security like you do, since the box will be behind the router, with WEP, MAC locking, and ultimately SSL encryption to the external browser).

Thanks for the info!

5120  Forum 2005-2010 (read only) / Bar Sport / Re: Your last purchase? on: December 28, 2010, 03:05:22 pm
I got one of those (just in metal chasing), but the original firmware on them sux, so instead I uploaded the yoics 9100a firmware instead.

Interesting - do you have a link or such describing the process (and/or why the original firmware stinks)? If it is really bad (I haven't even tried mine yet), updating it would be worth it...

5121  Forum 2005-2010 (read only) / Bar Sport / Re: Your last purchase? on: December 28, 2010, 01:52:52 pm
The 2.4 should have none of those problems, and should also have a better range with better picture, but I haven't tested those yet, but when my new wifitank is running, that will be the next thing I replace on it.

Some of those camera kits look similar to what I bought (though, once again, I don't recall if mine was a 900 MHz or 2.4 GHz; it might be that the 900/2.4 are frequencies for the US, while 1.2 GHz is for other countries?).

Something I recently bought with the intent of using it on my UGV project in the future was this:

It allows you to plug in four regular cameras (composite video) and view them via a built-in webserver over wired ethernet. Its powered off of a 5V 1A DC wall-wart (cameras are powered separately). Since my UGV has an 802.11g router/hub, I can easily plug it in (and power won't be an issue, since I'll have some fairly large 12 volt SLAs on-board).

Something to play with, anyhow!

5122  Forum 2005-2010 (read only) / Bar Sport / Re: Your last purchase? on: December 28, 2010, 12:10:14 pm
Also looking around for a possible wireless camera to go on this bot... if someone has suggestions, I'd love to hear em.

I've had great luck with a cheap wireless color "spycam" I bought on ebay years ago (can't remember if it was 2.4 GHz or 900 MHz). Its a little camera that has an antenna, along with barrel inputs for 9VDC (use a small 9V battery - it came with an adaptor), plus an RCA output for video (if you wanted to hard-wire it). It transmits to a small receiver box with antenna that outputs NTSC composite video for a television. I've had no problem with it transmitting all over my house via a small test-rig UGV (unmanned ground vehicle) rig I made a several years back. So, about a 100 foot range (probably much greater on open ground with line-of-sight).

At the time I got it for about $30.00 plus shipping (drop-shipped from HK); you can probably find something similar...
5123  Forum 2005-2010 (read only) / Bar Sport / Re: Your last purchase? on: November 27, 2010, 03:48:04 pm
Two fresh dungeness craps, first of the season.

Well, you must be feeling better!

5124  Forum 2005-2010 (read only) / Bar Sport / Re: Your last purchase? on: November 18, 2010, 06:19:17 pm
And would be a "stupid" thing to make, because all it probably will be able to power, is itself, and I am not even sure it can do that...

You'd probably have no problem doing that, as long as you ran the code on some timer interrupt (say every 30 seconds or longer), and went into a low-power sleep mode otherwise; you could probably easily keep the battery charged to run other things including the Arduino and the servos...
5125  Forum 2005-2010 (read only) / Bar Sport / Re: Your last purchase? on: November 18, 2010, 05:51:58 pm
[edit]And my little test setup[/edit]


A friend of mine has a similar setup, and bought (I think) nearly the exact same parts. He's using them for some kind of gardening monitor system, and says they work really great.

5126  Forum 2005-2010 (read only) / Bar Sport / Re: Your last purchase? on: November 17, 2010, 10:39:25 pm
I've been trying to cut back on that sort of thing.  In fact, I've recently been taking some things that I rescued out of work's dumpsters BACK to work's dumpsters.  I mean, a working perfectly 386sx PC is nice, but ... not really worth the space it takes up, anymore.  I don't want to end up on "Hoarders."

I used to have a 386 motherboard that I still kick myself over for "getting rid of". There are some graphics demos for the PC that won't work right on anything but a real 386. It was a nice board, too - mini-AT, stocked with 8 MB of simm, AMD 386DX40 IIRC.


I know what you mean, though. I'm approaching "critical mass" with my collection of old Polaroid cameras I've purchased over the past few years for the ultrasonic sensor. My intent is to tear 'em down, keep all the good parts (motors, optics, etc), recycle the rest. I've also got a couple of VHS cameras that need to be torn down, too. And RC cars...

Ugh - maybe I need to be on "Hoarders" (I don't have paths yet, and everything is fairly neatly stored - so I don't think it counts!)...

5127  Forum 2005-2010 (read only) / Bar Sport / Re: Your last purchase? on: November 17, 2010, 07:46:19 pm
Just picked up today a Friendly Robotic RL500 from a guy on Craigslist for $50.00. It likely needs new batteries, as well as a perimeter fence transmitter unit (they call it a "switch" for some wack reason). I doubt I'll get the transmitter though; I am trying to come up with a solution around that need (maybe I'll gut the mower and use it for a base for my own mowing system?). Just another piece-o-junk for later hacking!

5128  Forum 2005-2010 (read only) / Bar Sport / Re: Your last purchase? on: November 10, 2010, 01:01:47 pm
Last night I had a real surprise: I get home, go into my office, and notice a strange smell...

Long story short, my motherboard on my workstation had decided to short out (small burn on the bottom of the PCB and everything). I ended up making a run to Fry's Electronics to pick up a new motherboard and graphics card (my old motherboard had a built-in NVIDIA chipset video for dual-monitor output, so I had to get something similar because the new mobo only had a single VGA, and an intel chipset).

Tonight I get to go back  smiley-sad in order to get a different video card - the one I had purchased last night I found runs really, really hot (66 C) - it only has a heatsink and no fan, and since my system runs 24/7 - I just don't trust that - so its back to return it, and get something else with a fan.

A couple more gripes:

1) Why the hell, after we've been using tower systems for so long, are all the cards still designed "upside down" - how does this help with cooling - especially video cards?

2) Why is it that it seems getting a cheap dual-DVI output card at a large retailer like Fry's Electronics like pulling teeth? No, no - If I want to spend under $100.00 for a video card, I am only allowed DVI+VGA...

So - that was my "last purchase" - though certainly not the "last purchase" I wanted to make...


Then again, nothing caught on fire, and the power supply shut down properly - it could've been much worse...
5129  Forum 2005-2010 (read only) / Bar Sport / Re: Your last purchase? on: November 03, 2010, 10:26:21 am
Shame on you!

/typical knee-jerk millennial-baby response...

5130  Forum 2005-2010 (read only) / Bar Sport / Re: Your last purchase? on: October 30, 2010, 10:43:14 pm
Tonight I found another item at Goodwill - a Futaba 2-channel AM radio R/C kit; the transmitter is missing its battery door (seems to be a theme for me today!), but everything else was there. Got the transmitter, receiver, 6V battery holder/switch, crystals, two servos, control horns, and transmitter flags. All for $7.00!  smiley
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