Tone Generation


Is it possible to have Asterisk generate a tone with adjustable volume level under voice (2175HZ). This will be used to trigger a repeater atop a tower through a raspberry pi? Is there an API that I can write to to accomplish this task?



That’s a developer question, not an end user one, although I suppose you could hack it together with the conference application. These are end user forums. Really you need to use audiohooks.

Also using a tone in the middle of the speech range seems a strange choice. Such tones would normally be CTCSS ones, which are typically below the normal telephony range (maximum 250.3Hz), although they may get through if the system is purely digital or baseband. Note that only simple codecs are likely to reproduce low level pure tones well, as they are not speech like.

(It does seem that Motorola do use 2175Hz guard tones, although the protocol also involves the same tone at high level.

Thanks David. The repeaters are Motorola. The tone is only used on the uplink to the repeater to activate it and removed from the audio so you don’t actually hear the tone during the transmission. When the tone stops the repeater goes off line. It acts as a push to talk to remotely activate the repeater. I’m trying to help a friend who maintains the repeaters for the state of VT that are used by the police and fire departments. Having this feature will allow them to extend the range of their hand held radios by using the Internet a raspberry pi and an audio interface with an uplink to the repeater. Is there a developer forum? I’m new to asterisk and just have some preliminary info on the project.



There is a developer mailing list and IRC channel.