Search found 464 matches

by Newz2000
Mon Feb 02, 2009 11:47 am
Forum: General Discussion
Topic: Detecting when a specific item is near
Replies: 21
Views: 8846

Re: Detecting when a specific item is near

Wow, finding the right part is time consuming. Here's what I've figured out so far: * One lunch break isn't enough, two probably isn't either, especially if you actually intend to eat during your lunch break * For hall sensors, there are two different kinds of bipolars: * single output - detects nor...
by Newz2000
Mon Feb 02, 2009 9:28 am
Forum: General Discussion
Topic: Detecting when a specific item is near
Replies: 21
Views: 8846

Re: Detecting when a specific item is near

Aren't those button cells costly? Having said that I do see the LR44 (slightly larger size) in play alot for toys, musical cards, etc. AG3 packs of 100 for $10 on ebay (those are the 1.5v low capacity) to 50 for $10 (the 1.55v high capacity). Lithium chemistry (3v) CR2032 are probably a better deal...
by Newz2000
Mon Feb 02, 2009 5:45 am
Forum: General Discussion
Topic: Detecting when a specific item is near
Replies: 21
Views: 8846

Re: Detecting when a specific item is near

Not sure I follow. Why not 'kill' the found objects (to conserve power) and turn them off completely? If the rescued objects are fed through an opening into a secure box you will have a better shot at IDing them, prevent them from being "un-rescued" for double counting (I was a kid, too!), and have...
by Newz2000
Sun Feb 01, 2009 8:11 pm
Forum: General Discussion
Topic: Detecting when a specific item is near
Replies: 21
Views: 8846

Re: Detecting when a specific item is near

How big is the object? Is the object battery powered? How long does the object stay alive? Is this a contact or a proximity detector? How close does the object have to be to the proximity detector for detection? What happens if two (or more) objects arrive at the detector? How long does the detecto...
by Newz2000
Fri Jan 30, 2009 9:47 pm
Forum: General Discussion
Topic: Detecting when a specific item is near
Replies: 21
Views: 8846

Re: Detecting when a specific item is near

If you just click on SOT23 and APPLY FILTERS, you'll end up with 4 to choose from. To deselect, click the reset underneath. Yeah, it doesn't have to be sot23, just somethign hand solderable and preferably smt. I've never heard of these kind that can detect the north and south poles. I'm just curiou...
by Newz2000
Fri Jan 30, 2009 9:14 pm
Forum: General Discussion
Topic: Detecting when a specific item is near
Replies: 21
Views: 8846

Re: Detecting when a specific item is near

I'd be tempted to go with either magnets or RFID. A Linear Hall-Effect sensor can detect the difference between the north and south poles of a magnet. RFID is more complicated, but would also allow for expansion, ie, more than two objects or types of objects. Non-metallic objects will proably work ...
by Newz2000
Fri Jan 30, 2009 2:28 pm
Forum: General Discussion
Topic: Detecting when a specific item is near
Replies: 21
Views: 8846

Re: Detecting when a specific item is near

I'm thinking the kids will bring the device containing the microcontroller to the object and they could set it on the object or hold it close to the object. The game is going to be a "find and rescue" game. Devices containing a micro will blink slowly and the kids will have to try and find them in t...
by Newz2000
Fri Jan 30, 2009 12:51 pm
Forum: General Discussion
Topic: Detecting when a specific item is near
Replies: 21
Views: 8846

Detecting when a specific item is near

Can anyone suggest an inexpensive and easy to hand-build way for a small micro like a PIC 12F509 or ATtiny12 to detect when either object A or object B are near it? For example the tiny micro would react differently if it has been placed near item A than it would if were placed near item B which is ...
by Newz2000
Wed Jun 13, 2007 8:13 pm
Forum: General Discussion
Topic: Prius VS Hummer
Replies: 11
Views: 2469

Bologna. :grin: Do the math... the government realized how unrealistic their EPA tests were... The new tests... has dropped the Prius's EPA down by 25 percent to an average of 45mpg. ... The Prius costs an average of $3.25 per mile driven over a lifetime of 100,000 miles - the expected lifespan of t...
by Newz2000
Tue Jun 12, 2007 1:16 pm
Forum: General Discussion
Topic: Atmel or FPGA?
Replies: 7
Views: 2366

In the end, if he is like most college bound persons, he will want cash or a cell phone plan paid for him. Yeah, but I want to give him something that he knows is from me. He's on our parent's cell phone plan, and he has a summer job for cash, so he's well off. I like that board Yerry sent, because...
by Newz2000
Mon Jun 11, 2007 1:35 pm
Forum: General Discussion
Topic: Atmel or FPGA?
Replies: 7
Views: 2366

Atmel or FPGA?

Long time no chat. :-) My Brother is heading off to Iowa State University in the fall seeking an EE degree. He's off to a good start already, having passed out of his first two sem of Calc. I want to get him a gift that would be fun and would give him a further head start on his studies. I contacted...
by Newz2000
Fri Mar 09, 2007 11:12 am
Forum: General Discussion
Topic: Foremat Changes
Replies: 9
Views: 2588

I'm not able to edit my signature line... there is a big empty space where I used to be able to edit my .sig, which is interesting. Below the form here on the posting page, it says "Attach signature (signatures can be changed in profile)" which implies the functionality wasn't deliberately removed. ...
by Newz2000
Mon Feb 19, 2007 2:31 pm
Forum: General Discussion
Topic: AG13 batteries and laser pointers
Replies: 3
Views: 1179

AG13 batteries and laser pointers

Is there something special about AG13 batteries that makes them suitable for use in laser pointers? It seems they all come with two sets, and the batteries are not cheap when bought separately.

Can you replace them with a few AAA or more readily available coin cells?
by Newz2000
Mon Feb 12, 2007 8:02 pm
Forum: General Discussion
Topic: need a connector/extender
Replies: 2
Views: 1131

need a connector/extender

http://img411.imageshack.us/img411/6602/outsidesu9.th.jpg http://img411.imageshack.us/img411/5805/insideconnectormt6.th.jpg I've got this connector, I want to extend it by several inches. It's got 18 contacts, and the two outer contacts are slightly bigger than the rest. I don't know if you can buy...
by Newz2000
Fri Feb 02, 2007 10:58 am
Forum: General Discussion
Topic: Monochrome ntsc tv "out" project
Replies: 6
Views: 2335

KamPutty,

Do you have a picture of what you're doing? Sounds interesting, I'd love to see it.