Ideas needed for GPS/UHF/Car Radio setup

[quietguy]

Hi There

Want I want is to be able to...

Listen to my car radio

When the GPS gives audible directions the car radio will mute Radio (and
if possible 'play' the GPS message through it)

When a call comes thru on the UHF it will mute the car radio and, as
above, play thru the car radio

BUT the GPS has to have preference over the UHF

The GPS (Nuvi 310) has bluetooth and an audi O/P socket - the UHF (GME
TX6200) has an Audio O/P socket

Car Radio (original equip in '92 Toyota 4Runner) has bugger all on front
panel - might have to replace it with a newer model, or do some internal
mods

There is a gadget designed for motor biles which seems to do this, but
at $$$$$$$$ it is out of the question

So, looking for ideas, leads to circuits etc

Cheers

David

 

[quietguy]

Hi Jason

I am looking for circuits or would consider a kit but ready built is out of the question
due to $$$$$

The vox part shouldn't be too hard, but am not sure about how to give the GPS priority
over the UHF

cheers

David

 

[David L. Jones]

Hi There

Want I want is to be able to...

Listen to my car radio

When the GPS gives audible directions the car radio will mute Radio (and
if possible 'play' the GPS message through it)

When a call comes thru on the UHF it will mute the car radio and, as
above, play thru the car radio

BUT the GPS has to have preference over the UHF

The GPS (Nuvi 310) has bluetooth and an audi O/P socket - the UHF (GME
TX6200) has an Audio O/P socket

Car Radio (original equip in '92 Toyota 4Runner) has bugger all on front
panel - might have to replace it with a newer model, or do some internal
mods

There is a gadget designed for motor biles which seems to do this, but
at $$$$$$$$ it is out of the question

So, looking for ideas, leads to circuits etc

Cheers

David

It could be as simple as a signal detction circuit for both the UHF
output and the GPS, feed into two OR gates driving the mute control on
the radio (does it have one?). So if the UHF or the GPS gives an output
the radio is muted.

Then you probably need a seperate power amp and speaker for the UHF and
GPS, it might be too much trouble to swich it through into the radio
speakers.

You'll need a line level switch hooked onto the logic to mute UHF
signal when the GPS signal comes through.

Dave

 

[quietguy]

Then you probably need a seperate power amp and speaker for the UHF and
GPS, it might be too much trouble to swich it through into the radio
speakers.

I was thinking I would feed into the audio section of the radio - maybe at
the vol control, and at the same time remove/short the radio signal by way of
an OPTO to effect a mute.

You'll need a line level switch hooked onto the logic to mute UHF
signal when the GPS signal comes through.

Is this essential you think? I was thinking to just disconnect the (speaker)
OP of the UHF (ie the OPTO off) when the GPS gave a signal - eg perhaps a
PICAXE driving optos as switches to connect the units to the radios audio,
and using the interrupt to detect OP from either unit and logic to let the
GPS have priority.

Thanks for your reply

David

 

[David L. Jones]

I was thinking I would feed into the audio section of the radio - maybe at
the vol control, and at the same time remove/short the radio signal by way of
an OPTO to effect a mute.


Is this essential you think? I was thinking to just disconnect the (speaker)
OP of the UHF (ie the OPTO off) when the GPS gave a signal - eg perhaps a
PICAXE driving optos as switches to connect the units to the radios audio,
and using the interrupt to detect OP from either unit and logic to let the
GPS have priority.

Sure, plenty of ways to do it.
Don't need a PIC-AXE though, just a circuit which detects audio output
from the GPS and the UHF. i.e. a high when there is signal, low when
there isn't. Should be pretty easy as both of those outputs should have
no signal when not active, so the threshold level is easy. The output
from the signal detect circuit then drives some TTL logic which then
disables the appropriate audio channel by your chosen method.

Dave

 

[two bob]

Hi There

Want I want is to be able to...

Listen to my car radio

When the GPS gives audible directions the car radio will mute Radio (and
if possible 'play' the GPS message through it)

When a call comes thru on the UHF it will mute the car radio and, as
above, play thru the car radio

BUT the GPS has to have preference over the UHF

The GPS (Nuvi 310) has bluetooth and an audi O/P socket - the UHF (GME
TX6200) has an Audio O/P socket

Car Radio (original equip in '92 Toyota 4Runner) has bugger all on front
panel - might have to replace it with a newer model, or do some internal
mods

Toyota mute is the 'empty' plug, next to the white lead of the small plug of
the radio (if it has mute in that model)

I have a very novel solution:
Turn the radio down to a civilised level so you can hear the GPS and UHF.
It works for me, I dont have a UHF, but I have a GPS and 2 mobile phones and
occasionally 3 screaming kids.

 

[quietguy]

Thanks for the reply Two Bob

I haven't pulled the radio out yet to check if it has a mute, but will do soon.

Re hearing the units, I think my hearing might be winding down a bit as I have
trouble hearing the GPS over road, car, and traffic noise, without the radio
playing - 4WD diesels are not the quietest of vehicles, but a new one right now
is not an option. The UHF is not too bad, but the Nuvi GPS has a very limited
audio o/p

Cheers

David