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Getting Started with Bluetooth (or otherwise wireless) Project

3L3

Aug 10, 2012
1
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Aug 10, 2012
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I am a complete novice with electronics, but have a device I would like to create. I'm hoping someone can tell me two things: (1) is the described device possible to create? and (2) would this be something that a determined person could do with no prior experience?

I am a programmer and a teacher and have made a game that allows students to ring in for questions that I ask. The first student to ring in gets an opportunity to answer the question to get points for their team. Presently, I am connecting keyboards to my computer so students must press a specific button to ring in.

I would like to create a device that has about five cables coming out of it, each of which is attached to a single button (preferably the five buttons would be daisy-chained, if that's the correct term, instead of having five cables coming from the device). When the button is pressed, I would like to send a basic signal to my computer wirelessly. The signal could be as simple as a keystroke (as though a keyboard button was pressed) or it could be some other unique identifier that I could read in an Objective-C (Cocoa) program. Is there a way to accomplish this wirelessly? Would Bluetooth be appropriate (this seems advantageous because my computer has Bluetooth built in)? Is this too complex of a project for a beginner? Is this doable within a $50-$75 range?

I thank you in advance for any guidance you might offer me!
 

GreenGiant

Feb 9, 2012
842
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Feb 9, 2012
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842
for a beginner this seems a bit complex but I think with some time and effort it is doable.

Quick question though, 50-75 per group or as a whole for the entire project?

for each group you can use an Arduino, and a bluetooth shield and some creative programming to get the buttons to work right, not sure if itd be possible with them daisy-chained, but doable, this will cost somewhere around 60 or so apiece though (25-30 for Arduino, 15-20 for shield, and a little extra for the various components needed)
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,510
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Jan 21, 2010
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25,510
As much as some other people tend to dismiss the approach I'm about to suggest...

There are an number of "Arduino bluetooth" modules on the market. These are typically a module which has puns so it can be mounted on one of the Arduino boards, and often are quite simply driven -- perhaps with some simple serial protocol.

Combine this with an Arduino board (one of the smaller ones would be fine) and some programming (It sounds like you have the experience for this) and you're 80% of the way there.

The last 20% will always be harder is more expensive than you imagine, in this case it's the box to mount this in, and cabling/boxes to put the buttons on.

There is no real reason why you can't daisy chain the boxes (5 boxes could use 6 core cable between them, 5 for the buttons, and one for ground, although an additional Vcc connection so that you actively pull the wires up or down might be better.

About the only trick will be to (maybe) debounce the switches, the rest should just be straightforward.
 

CocaCola

Apr 7, 2012
3,635
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Apr 7, 2012
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3,635
As much as some other people tend to dismiss the approach I'm about to suggest...

It's a good suggestion, but from a monetary stand point @ 50 units it's almost certainly cost effective to make your own board, even if it's a rip of the Arduino & Bluetooth shield pin for pin (less unneeded stuff)...

Especially since the Arduino Bluetooth shield is nothing more than a break out board to Arduino pins, fitted with the cheap Asian BT module... $6 Asian module vs $20 for the same $5 Asian module mounted on an Ardunio Shield board...

Same with the Arduino at this point, the AVR chip, regulator, some caps and a crystal is a few bucks vs $10, $15 or $20 for the Ardunio...

Over 50 units you could save yourself about $1000 doing your own boards...
 
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