Hi all,

Here's the problem: My brother, son, and I, are all racing fans (F1, ALMS, etc.). These cars are super loud so we wear hearing protection at the races. The problem is that once you have your hearing protection on, you can't chat with each other.

I found these headphones on ebay for cheap and picked up three pairs:

http://www.peltor.com/peltor.com/comm_detail.cfm?prod_family=BlueTooth&ind_prod_num=MT53H7AWS2001

What seems nice about these is that they offer good hearing protection, have a noise-cancelling mic attached, and a bluetooth radio. I tried them with my cell phone and they work great so I thought about just setting up a conference call on three cell phones and we would be in business. The problem is that when you have 100,000 race fans, getting a cell signal can be nearly impossible.

I realized what we need is a central bluetooth intercom system that we can pair each headphone with that would manage the communication. They make these for motorcycles for about ~$200-300 but I was wondering if it might be possible to build one. I have no experience with bluetooth circuitry but I like a challenge. Does anyone have a thought about whether or not this is a reasonable project and if so, where one might start?

Many thanks in advance!

Kevin

P.S. I tried this solution but the sound quality was so horrendous it was essentially unusable:

http://www.instructables.com/id/Build-a-Bluetooth-Intercom-for-bike-rides-motorcy/

 

Start by looking at data sheets of commercially available bluetooth RF modules to find out their power supply and control system requirements.

http://www.panasonic.com/industrial...h/index.aspx?gclid=CKrY2ZvsybECFSVvTAod1GYAqw

http://www.bluegiga.com/Bluetooth_Modules

http://www.rovingnetworks.com/products/Bluetooth_Modules

http://www.lairdtech.com/Products/Wireless-M2M-and-Telematics-Solutions/Bluetooth-Module/

http://www.st.com/internet/imag_video/subclass/1324.jsp

http://kcwirefree.com/

http://www.fujitsu.com/us/services/edevices/components/wireless-modules/bluetooth/

http://www.rfm.com/products/wi-fi_bluetooth.php

http://www.lemosint.com/bluetooth/

and many more.

 

Thanks for the leads! After some reading I think what I need is a full-duplex audio module (maybe one of these? http://kcwirefree.com/audio.html). Seems a bit daunting but that is not an unfamiliar feeling at the start of project...

 

If you weren't set on building your own, you could just use the Motolky application on an Android smart phone.

 

Does this app require a cell signal? If not, I'll check into that. Thanks!

 

Not sure whether this would work or not (I just recently got into circuitry) but you might be able to make a FM Transmitter and receiver and use those headsets with it.... Not sure whether or not the FCC would like the idea, though.

 

Does this app require a cell signal? If not, I'll check into that. Thanks!

No, but it does have to be installed on each phone. There are other bluetooth intercom and chat applications you might look at. One thing I noticed is that the number of users is quite limited with bluetooth but significantly larger if linked by WiFi. I don't know if any of the available applications would allow full duplex group communication using your headsets. A stand alone bluetooth chat hosting device would be nice.