Intercom project need help

Don't reinvent the wheel or in this case the walkie talkie.

There are lots of systems out there that are wireless communication and I am sure there are wireless intercoms.
Telex makes a wireless headset intercom system (watch the coaches on the sidelines of an American football game) and I am sure other companies do as well.

My home phone has an intercom built into the wireless handsets. I can page any of the other 4 handsets. I can also use it to listen to a room without paging.

What specifically do you want to be able to do?

Communicate with people in other rooms?
Listen in to other rooms like you would with a baby monitor?
Do you want it to be limited in range?
Do you want it to be secure from eavesdropping?
Do you want something that people wear like a wireless lapel mike?

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i just selected this project and it doesnt matter which kind of remote intercom it is but i want to know have you got ne ideas for me as im just starting it. It would be greatly appreciated.

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i just selected this project and it doesnt matter which kind of remote intercom it is but i want to know have you got ne ideas for me as im just starting it. It would be greatly appreciated.

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i just selected this project and it doesnt matter which kind of remote intercom it is but i want to know have you got ne ideas for me as im just starting it. It would be greatly appreciated.

i am a student and im doing a project so i would want something fairly difficult

You are still not giving much information. You need to narrow it down a little more.

A science project? You could actually build a wireless intercom using 2 computers with speaker and microphone and use a wireless network to communicate between the 2.

An electronics project? You could build a radio system yourself using spread spectrum radio so it can't be overheard.

There are many ways you can go on this. Buy a wired intercom system and turn it into a radio system.
Take existing off the shelf parts and build your own system.
buy 2 walkie talkies and put them in a different box with a power supply.

Hi Danny,
There are indeed many approaches. If you would like a challenge and a bit more than just taking off the shelf modules and putting them together like lego, most likely you will need to progam a micro processor. Which is fun.

Why not drop in on a forum that discusses a propular micro like www.avrfreaks.com which is focused on the 8 bit AVR line of micros from Atmel (good for a hobyist as easy to buy and have lots of tools). There are discussions on wireless analog, digital, spread spectrum, ADPCM, wi-fi and people can give advice on schematics, componet selection and programming techniques.

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hi michael
Most projects being done this year are used by a programed micro but we dont have much knowledge about the picc program. I will look into it. Thanks

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parados
I looked up the varios type of remote intercoms Party-line Systems, Matrix Systems, Wireless Systems and i want info on any of them. I thought the party-line system would be difficult cause of trying to get the slip on mic.

I also looked up more today and i must do a simplex system (walkie talkies) cause we have a budject. If anyone has ne circuits or schematics plz email me at [email protected]

Have a look at this link http://www.commlinx.com.au/RF2400DV.htm

The site has a few other useful modules, don't forget Google is your freind .

A comment on MicroChip and the Pic, which is not the same as the AVR series from Atmel (the language and tools are different). Personally I prefer the Atmel chips, but price wise they are similar, both may have their strong points. There are tons of others from Toshiba, NEC, Samsung and dozens of others and come in a dizzying choice. I guess if you end up using a micro and your school already has tools (in circuit emulator) set up for the Pic go with that, you may be lucky enough to even find someone who knows the first thing about programming it.

Heres another http://www.maxstream.net/?trackcode=bizcom

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I have been talking to the lecture that will be supervising me and he said that i would need to build a wireless intercom. He said it would be good if i managed to do it using a transciever chip, audio amps and filters.

Are you supposed to design the circuit yourself?

Here is a circuit from a 1966 kit walkie talkie that should give you the basics.
http://users.arczip.com/rmcgarra2/c-100.html

There are a few basic circuits you need to build it.
a sending and a recieving circuit (you can probably get this in a single chip)
an amplifier
a power supply (or battery)

Nothing quite so satisfying as breaking it down and making it work yourself. It wouldn't be the same if we just gave you all the answers.

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well i can look up circuits as long as i modify them.

Danny,
How much is your buget? how much will they support you? Unless you are aspiring for a career in hardware RF try to pursuade your lecturer to allow you some leeway.

I've developed dozens of RF products for comercial use, without shielded rooms and knowledge of latest techniques , what you are learning is ground work which will be replaced by newer ideas later.

I would be happy to discuss, however if you would like to "look up and modify" heres a site for starters, try transmiter and receiver circuits.

http://www.discovercircuits.com/list.htm

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As far as i know the budject we are given is 150euro. Past yr student designed one with an ADC and DAC converters on the transmitter and reciever with also a transciever. I looked up the site already and it will help me on the amplifier part of the circuit.

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any website that i could look up how to connect an adc to the transciever to the antenna.