Walkie Talkie activating button

[dleebell]

Hi

I've got a project where I am wanting to use two walkie talkies (WT) with an add on feature. Basically i want to have both walkie talkies with a button.  Where one of the walkie talkies is able to activate the other button. So...

Walkie Talkie 1: Button Off = Walkie Talkie 2 Button Off
Walkie Talkie 1; Button On = Walkie Talkie 2 Button On

The system only works one way where WT1 activates WT2.

I have been told that I can send informaton via walkie talkies using either a 556 Chip or a Nordic nRF24L01 Chip, both of which send an audio frequency. Either on will be connected to WT1 and my arduino connected to WT2.

Are there any other ways of activating the button through the WT's (wirelessly) without playing an audio that can be heard?
Or is it a matter of just raising the frequency to the extent of not being picked up by the human ear...

Many Thanks
Dominic

[vk3yedotcom]

Not quite sure exactly what this is for but if you disconnect the speaker from the receiving unit the audio being transmitted won't be heard.

[dleebell]

It's for a project of mine at uni.

So if I disconnect the speaker for the period of 'deactivating' or 'activating' button the arduino is still able to pick up the frequency? From which chip 556 or Nordic nRF24L01.

many Thanks
Dom

[Howardlong]

Assuming you want this in-band, have you considered sub-audible tones? Look up CTCSS or PL tone.

[G7PSK]

Many two way's come with a repeater function these days, usual y works with a CTCS or.DTMF   

[vk3yedotcom]

It's for a project of mine at uni.

So if I disconnect the speaker for the period of 'deactivating' or 'activating' button the arduino is still able to pick up the frequency? From which chip 556 or Nordic nRF24L01.

You could disconnect the speaker permanently if you wanted. It doesn't alter the radio's behaviour. Just like how a portable radio doesn't stop playing when  you unplug the headphones.