Roboduino Bluetooth

[Adityav95]

Why is this bluetooth module so cheap?
 http://www.ebay.com/itm/Arduino-Bluetooth-Module-Slave-Wireless-Serial-Port-4P-/220852015499?_trksid=p5197.m7&_trkparms=algo%3DLVI%26itu%3DUCI%26otn%3D4%26po%3DLVI%26ps%3D63%26clkid%3D2866999681675276453

When comoared to something like:
 http://www.sparkfun.com/products/582

Q2. Should i buy the ebay one or this one:
      http://www.sparkfun.com/products/10253

I will be using any one of the modules to use voice control via android to my roboduino and as u might have guessed i dont want to spend more than $15.

Thnx
Aditya


      
      

[richiereynolds]

Can't comment on this exact model but I'd try to get some reports from someone who's bought one. I bought a cheap DF Robot bluetooth module on ebay that never worked, wasn't dear but wasted a lot of my time. Whereas I've had two more expensive ones that worked without any bother, which was definitely worth the extra cash!

By the way, if you do buy it, remember to report back here how it went for the benefit of the rest of us bargain hunters!

[Adityav95]

So is this better at least?
  http://www.sparkfun.com/products/10253

I really cant spend more than $15. So its the ebay module or this one.

And by the way....for bluetooth all i need is one of the above mentioned chips and a computer with bluetooth right?

And it WILL BE compatible with roboduino?

Thnx
Aditya

[joe61]

Others here know more than I do about this, but when I tried bluetooth I found that I had to have at least one class 1 adapter. Since I was only sending from a PC I put the class 1 adapter on the PC. Even so I had limited range, and frequent disconnections. The cost of the eBay module may mean that it's a low power unit. if the android doesn't have a class 1 adapter, you may need this one to be.

Joe

[Gertlex]

The one on eBay is a class 2 device, so range is going to top out at 10 meters (30ish feet).  Not something you want for a moving robot (because anything in between your computer and robot is going to have a good chance of completely breaking the connection).

As best I've been able to find, using bluetooth serial connections with windows is a 1-way connection thing... E.g. can send, or receive data only.  Supposedly there are work arounds, but I've been unable to find them.

As for why so expensive... I really don't know, but the prices haven't dropped on this hardware in the 5 or so years I've been watching... :/

(My alternative recommendation is to use Xbees, but that's $80 + shipping for the two xbees, and the two adapter boards for them)

[Adityav95]

1. Then will this do? I'm really streching my budget here.
 http://www.sparkfun.com/products/8497

2. Is this module all i need to connect to my roboduino? Like do i need anything else at all to add bluetooth connectivity?

[Adityav95]

Could someone pls tell me how do i use my android to control the robot? like is there any app? ive heard of an app called cellbot....but not sure...

Thnx
Aditya

[Soeren]

Could someone pls tell me how do i use my android to control the robot? like is there any app? ive heard of an app called cellbot....but not sure...

It just didn't occur to you to write "cellbot" in a Google search? 

[Adityav95]

Firstly, as Gertlex said 30 feet is too low a range. Therefore I have decided to go with something better. Some questions:

1. Any idea how good the RN-41 bluetooth module is?
2. Would I need a breakout board as the module with breakout board costs $35 more than just the module?
3. How hard is it to use the module with the roboduino without a breakout board?( Is it tooo hard?)

I would also like to know why a WT-41 module from blue-giga costs only $40 but also has a whopping 1000m range? Will someone tell me whether I will need anything other than this module to 'bluetooth enable' the roboduino??

Thnx a lot for answering (and for being patient!)
ADITYA