Geekzone: technology news, blogs, forums
Guest
Welcome Guest.
You haven't logged in yet. If you don't have an account you can register now.




16 posts

Geek


Topic # 30299 4-Feb-2009 07:24
Send private message

ok, you know the lasers that are inside of candy machines that see if the candy was dropped? i wanna make one of those for my hallway so i can know if someone's coming toward my room. Does anyone have a plot to make one. I'm not doing anything illegal, and I'm not a paranoid freak, I just wanna make a fun circuit.

Ps. i do have a basic understanding of electronics (digital and non)

Create new topic


16 posts

Geek


  Reply # 193886 4-Feb-2009 08:25
Send private message

bumpism



16 posts

Geek


  Reply # 193889 4-Feb-2009 08:38
Send private message

no one?

 
 
 
 


I iz your trusted friend
5811 posts

Uber Geek
+1 received by user: 140

Mod Emeritus
Trusted
Lifetime subscriber

  Reply # 193891 4-Feb-2009 08:52
Send private message

Why don't you just get one of those door alarm/sensor thing that you often see at the shop door where it make "buzzzz" as someone enter?




Internet is my backyard...

 

«Geekzone blog: Tech 'n Chips Takeaway» «Personal blog: And then...»

 

Please read the Geekzone's FUG

 


5092 posts

Uber Geek
+1 received by user: 1211

Moderator
Trusted
Lifetime subscriber

  Reply # 193896 4-Feb-2009 09:08
Send private message

Perhaps wait a while to see if anyone answers?  It's only just gone 9am so people are still arriving at work and waking up at home, having breakfasts and showers and getting ready for their days.  Its highly unlikely you'll get a response if you're bumping this early in the morning.

I iz your trusted friend
5811 posts

Uber Geek
+1 received by user: 140

Mod Emeritus
Trusted
Lifetime subscriber

Reply # 193914 4-Feb-2009 10:10
Send private message

*hehe* Gehenna, based on the flag of the posts... he's from USA...

<french accent>American!</french accent> *hehe*




Internet is my backyard...

 

«Geekzone blog: Tech 'n Chips Takeaway» «Personal blog: And then...»

 

Please read the Geekzone's FUG

 


1240 posts

Uber Geek

Trusted

  Reply # 193924 4-Feb-2009 10:34
Send private message

What you need is a programmable IC, and an ultra sonic sender and receiver. So than when someone walks infront of the ultra sonics, the time for the sound to return is different and your IC can do whatever you want it to do...send out sound to a speaker etc.

There must be a laser diy kit out there, but I think it would be much harder to make from scratch. iirc they work by the laser connecting with a metal plate and giving it energy(simplified that a lot), and when something gets in the way, the circuit is broken...then the same as before.

or an even simpler circuit would be a laser aligned with an LDR.



16 posts

Geek


  Reply # 194165 5-Feb-2009 07:03
Send private message

gehenna: Perhaps wait a while to see if anyone answers? It's only just gone 9am so people are still arriving at work and waking up at home, having breakfasts and showers and getting ready for their days. Its highly unlikely you'll get a response if you're bumping this early in the morning.
good point. i tend to forget that this isn't a US site. sorry.



16 posts

Geek


  Reply # 194166 5-Feb-2009 07:05
Send private message

Fossie: What you need is a programmable IC, and an ultra sonic sender and receiver. So than when someone walks infront of the ultra sonics, the time for the sound to return is different and your IC can do whatever you want it to do...send out sound to a speaker etc.

There must be a laser diy kit out there, but I think it would be much harder to make from scratch. iirc they work by the laser connecting with a metal plate and giving it energy(simplified that a lot), and when something gets in the way, the circuit is broken...then the same as before.

or an even simpler circuit would be a laser aligned with an LDR.
coolio. i'll totally do the laser LDR thingy. sounds easiest.

2784 posts

Uber Geek
+1 received by user: 121


  Reply # 195174 10-Feb-2009 19:45
Send private message

photo-electric light-beam. Cheap.

Most of the cheaper laser-diodes aren't designed to be used for extended periods (the type used in laserpointers etc), so you'll want to invest in a better quality one or it'll likely go "pop" after a few hours.

Or, get a rug and stick a pressure-plate under it, ultra-easy and doesn't require any IC programming. Plus you won't risk blinding your pet(s) if you happen to have any and were going to mount it low.

I had one years ago which was just an LDR wired pretty much straight into an RS232 port of an Atari 800XL which I could then PEEK to see what the current resistance was and do things accordingly. The end result was that you could use it to trigger a relay to turn the lights on when it got dark outside or something similar. Back then laser-diodes were a bit out of my price range. It was amusing to use it to change the sound pitch relative to light as a sort of poor-mans theramin.



16 posts

Geek


  Reply # 199330 5-Mar-2009 06:40
Send private message

i didn't think of pressure sensitive, thanks

84 posts

Master Geek


  Reply # 199882 8-Mar-2009 11:52
Send private message


Why not just get a PIR and blind the sides of it to narrow the detection field?

All you need then is 12VDC, and something to sound. Should be about total of $20 spent.


Create new topic



Twitter »

Follow us to receive Twitter updates when new discussions are posted in our forums:



Follow us to receive Twitter updates when news items and blogs are posted in our frontpage:



Follow us to receive Twitter updates when tech item prices are listed in our price comparison site:



Geekzone Live »

Try automatic live updates from Geekzone directly in your browser, without refreshing the page, with Geekzone Live now.



Are you subscribed to our RSS feed? You can download the latest headlines and summaries from our stories directly to your computer or smartphone by using a feed reader.

Alternatively, you can receive a daily email with Geekzone updates.