I'd like an extra option in the cell phone mute function:

switch to aux during phone conversation. And return to the previous source after hanging up, off course.

My cell phone car kit supports connections to a radio aux in.
This way, I could remove the ugly car kit speaker. But only
if the Empeg software supports it.

Rumor has it that you can do this with Hijack, and it works.

Tony - Care to elaborate or point me to a thread? All I could find was a thread 'Auto Sense Aux In' , which seemed to conclude that you had to remap a button to 'toggle'. Or is the mute line also considered a remappable button?

I'm interested not for my phone (already have an installed speakerphone) but for my Copilot 2.0 GPS for the ipaq that should be here tomorrow. It will give turn-turn voice directions which would be a great application for a true auto-sensing aux it.

So, any more hints?

-Zeke

Look here and search for extmute_on and extmute_off

Mea Culpa! I thought I had read that section, but not carefully enough. Can anyone suggest a relay that would be sensitive and fast enough to pick up and switch 12V from a typical headphone out level? I can find out the voltage myself easily enough, but does anyone have a sage word on which type of relay would be most appropriate (reed, power, solid state, general purpose etc)? I do have Digi-Key & Mouser catalogs. I figure this can be a wee breadboard project, especially since Nosferatu has already shown how to connect a phono cord to the aux in (thread subject 'speakerphone?' 12/29/01). If I get this working I promise a 'how to' post. Besides, if a non-electronics person like me can make it work, anybody can.

-Zeke

The [url=sound.westhost.com/project38.htm]circuit here{/url] I have found to be one of the most useful audio circuits on the web, and it spawned several projects and ideas for me!

Someone else mentioned here on the board a little device that detects GSM transmission and provides an output that is active when the phone is in use. Apparently it's smart enough that it won't switch for SMSes and cell changes etc.

Have a look here

try that again

Hey Zeke,

I do the same thing for my Nav and phone but I do not use the Aux input. Instead, get either a ground loop isolator (for line level inputs) or a Impedance matching unit (for speaker level) and connect them in parallel to the outputs from the empeg into your amp. You then do not need to worry about switching and the associated clicks. This works perfectly for me and I cannot hear any crosstalk from the empeg at all. The other benefit is that I have my empeg to mute to 50% from either the Nav or the phone kit mute line and the relevant sound just overpowers the music but without it stopping altogether.

Interesting. But from the manual it appears Hijack won't be able to return to the previous source after the call is finished, just to a predefined souce.

Surely, if this were to be implemented in the player, it could return to the previous source.

Pim

Dava,
That does sound like a better proposition. After using the Nav for a whopping two hours or so, I think any relay/automuting would get really annoying as it tends to beep quite a bit in non-highway driving. I don't have a switched mute line from either the phone (Motorola installed hands free kit) or the Nav (it's an ipaq with an external GPS receiver), but I think I can make the 2" reach over to the stalk controller to mute or hush. Having the sound injected right to the amp would be great.

Where do I get (or how do I make) the impedance matching unit or ground loop isolator? It sounds interesting.

-Zeke

I got both units (very similar in spec) from CPC in the UK (www.cpc.co.uk). They were about £8 each so no problem there. Inside there is a pair of audio transformers which isolate the supply from the output. The Impedance matching one has a few resistors in too but nothing more than that. My guess is that the Ground Loop version just has 1:1 windings of 20Kohms or so but the Speaker level impedence matching one has 4ohm primarys and 20K secondarys.

CPC's catalog pages are not working, something about a "new system being introduced". Do you have a MFG part number or the like so I can poke around a bit more for them?

-Zeke

Sorry No,

I know they were made by Altai but I can't be pulling my dash apart again just to have a look for a number. I would think that any ground loop isolators would do the job. If I do have any other reason to revisit my in-dash hell then I will be sure to let you know.

The name'll take me a long way. Thanks. I'll post the details if/when I find the thing. Don't remind me about dash hell, my switched power line is loose and I have to enter the rats nest some time this week...yuck.

-Zeke