Post by thread:[EE]: Send audio through car speakers

Hi All, I'd like to make my handheld PC play its audio through my car speakers - for announcing incoming messages, reminders, etc... My [factory] car radio does not have an auxiliary input - and that's not what I want anyway. I'd like to build something that goes between my car radio and the speakers. When audio is being played from the pocket pc it should attenuate (but not necessarily mute) the stereo, amplify the pocket pc audio and pump it from the car speakers. I know there are devices that will play audio over 88.x Mhz - this is not what I want - I'd like to listen to whatever I want to on the car radio, in addition to hearing the pocket pc. Any ideas?? Thanks! -matt -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

On Tue, 9 Sep 2003 11:43:36 -0400, you wrote: >Hi All, > >I'd like to make my handheld PC play its audio through my >car speakers - for announcing incoming messages, >reminders, etc... > >My [factory] car radio does not have an auxiliary input - >and that's not what I want anyway. I'd like to build >something that goes between my car radio and the speakers. > >When audio is being played from the pocket pc it should >attenuate (but not necessarily mute) the stereo, amplify >the pocket pc audio and pump it from the car speakers. > >I know there are devices that will play audio over 88.x >Mhz - this is not what I want - I'd like to listen to >whatever I want to on the car radio, in addition to >hearing the pocket pc. > >Any ideas?? A relay and a few resistors. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

At 06:31 PM 9/9/2003 +0100, Mike Harrison wrote: >On Tue, 9 Sep 2003 11:43:36 -0400, you wrote: > >>Hi All, >> >>I'd like to make my handheld PC play its audio through my >>car speakers - for announcing incoming messages, >>reminders, etc... >> >>My [factory] car radio does not have an auxiliary input - >>and that's not what I want anyway. I'd like to build >>something that goes between my car radio and the speakers. not a simple thing. you can't just tie high power outputs together as it appeared someone else was suggesting. basically, you'd have to provide a new final amp, pad your existing radio down to line level, and mix that resistively, with the other sources. i'm considering the same thing for a ham radio project, where i have as many as six radios to deal with.. i also want to drop the radio volume if i'm transmitting, or if any of the transcievers has audio, plus spread the transciever audio out across the soundstage. not trivial, but not too hard either. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

It used to be easy... you just picked up the audio at the vloume control. Solid state concealed that and then we went to a couper that went throught the cassette tape head. They screwed that up by checking for slack tape. The only simple solution I know of is to mount a pair of computer speakers to allow easy acess to audio. I do that for Ham radio gear and an onboard nav computer in the Motor Home. I have been contemplating an amp that plugs between the speakers & the radio, but no real activity at this time... PS: Every RF solution I have seen has been very poor. John Ferrell 6241 Phillippi Rd Julian NC 27283 Phone: (336)685-9606 spam_OUTjohnferrellTakeThisOuTearthlink.net Dixie Competition Products NSRCA 479 AMA 4190 W8CCW "My Competition is Not My Enemy" {Original Message removed}

At 03:35 PM 9/9/2003 -0700, you wrote: >It used to be easy... > you just picked up the audio at the vloume control. > Solid state concealed that and then we went to a couper that went throught >the cassette tape head. They screwed that up by checking for slack tape. Some of the cassette devices have a mechanism inside that simulates the tape. Gears and so on. I don't recall the details. I took one apart because it was put together wrong at the factory (tracks were swapped). It had a major consumer-electronics brand name (Sony or Panasonic, IIRC). Best regards, Spehro Pefhany --"it's the network..." "The Journey is the reward" .....speffKILLspam@spam@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

Matt. Many car radio systems use a bridge output for extra power - therefore a simple relay circuit has its dangers, although a double pole break before make type should work OK. Might pay to keep some resistive load on the radio while switched out however. If you only use the radio - not the tape or CD etc. you could try injecting a modulated carrier at the IF frequency - this should override the radio signal due to capture effect (FM radio). This would then work regardless of the station you were listening to. Richard P Hi All, I'd like to make my handheld PC play its audio through my car speakers - for announcing incoming messages, reminders, etc... My [factory] car radio does not have an auxiliary input - and that's not what I want anyway. I'd like to build something that goes between my car radio and the speakers. When audio is being played from the pocket pc it should attenuate (but not necessarily mute) the stereo, amplify the pocket pc audio and pump it from the car speakers. I know there are devices that will play audio over 88.x Mhz - this is not what I want - I'd like to listen to whatever I want to on the car radio, in addition to hearing the pocket pc. Any ideas?? Thanks! -matt -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

{Quote hidden}> Hi All, > > I'd like to make my handheld PC play its audio through my > car speakers - for announcing incoming messages, > reminders, etc... > > My [factory] car radio does not have an auxiliary input - > and that's not what I want anyway. I'd like to build > something that goes between my car radio and the speakers. > > When audio is being played from the pocket pc it should > attenuate (but not necessarily mute) the stereo, amplify > the pocket pc audio and pump it from the car speakers. > > I know there are devices that will play audio over 88.x > Mhz - this is not what I want - I'd like to listen to > whatever I want to on the car radio, in addition to > hearing the pocket pc. > > Any ideas?? > > Thanks! > > -matt Interesting that you bring that up right now. Not even 2 weeks ago I did the exact same thing. I've gotten really tired of listening to the radio, and wanted a CD player. Unfortunately, I can't really afford to go out and get one. So I did the next best thing - I built an interface between my car speakers and my portable CD player. To do this, I opened up my dashboard and found the audio connector. This is in a 1991 Geo Prizm, by the way (shares alot of parts with a Toyota Corolla of the same era). Going online, I found the pinout for the connector. I measured the resistance between speaker pinouts to be 6 ohms - still can't quite understand that one. Perhaps dual cone or something? Anyway, price was the name of te game here, so I went to Fry's Electronics and bought 2 sets of the cheapest amplified computer speakers I could find. Generally these run on 12v or less, perfect for a car. Some creative dismantling provided me with a pair of 2-channel amps. I soldered some connections to the boards, removed a few things that were unnecessary, and they were good to go. The audio connector in the car connects directly to my audio-adapter-car-amp-unit-thing...this project. The exisiting car stereo also connects to it. I connected 2 4PDT relays up such that when the unit is off, the relays connect the car directly through to the stereo and it acts like my project isn't even there. Powering up the unit, the relays connect the speakers to the new cheap amps. Isolating the two devices by relays helps me make sure I don't royally screw up the stereo or the electrical system. A 1/8" stereo jack provides input from the CD player, which sits on the center console between the seats. A few resistors were used to match the speakers to the amps. Don't forget to do that! I did end up blowing both cheap amps the first time around. I put too much faith in the power supply being regulated, I believe, and that came back to bite me. Well, zap my amps anyway. I replaced the amps with the same type, and installed a voltage regulator. No problems yet. Useful tip: A trip to Pick-Your-Part provided some connectors without spending $$ at the dealer. Here are two pictures of the unit when completed: www.togo84.com/journal/random/my_stereo_amp_2.jpg http://www.togo84.com/journal/random/my_stereo_amp_1.jpg If you'd like more information, I'll keep writing...! -Tony -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads

> -----Original Message----- > From: Alan B. Pearce [SMTP:.....A.B.PearceKILLspam.....RL.AC.UK] > Sent: Wednesday, September 10, 2003 11:32 AM > To: EraseMEPICLISTspam_OUTTakeThisOuTMITVMA.MIT.EDU > Subject: Re: [EE]: Send audio through car speakers > > >Tried to draw 1 in ascii art it all went wrong and orcad v 3 > >wont make decent export file # > > Do a "print screen" once you have the relevant piece of circuit full > screen, > and then open something like Microsoft Photo Editor and paste off the > clipboard. Then save as a suitably small jpg. > Save as a suitably small GIF for line drawings, heavy jpeg compression makes schematics virtualy unreadable. Mike ======================================================================= This e-mail is intended for the person it is addressed to only. The information contained in it may be confidential and/or protected by law. If you are not the intended recipient of this message, you must not make any use of this information, or copy or show it to any person. Please contact us immediately to tell us that you have received this e-mail, and return the original to us. Any use, forwarding, printing or copying of this message is strictly prohibited. No part of this message can be considered a request for goods or services. ======================================================================= Any questions about Bookham's E-Mail service should be directed to postmasterspam_OUTbookham.com. -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics