Doorbell interrupt for stereo system?

[Kaido]

My friend has a wireless doorbell system in her shop, one of those contact-closure types of systems for twenty bucks or so that chimes when the front door is opened. I'm currently putting in a stereo system for listening to the radio throughout the store. She wants the doorbell to interrupt the stereo system and ring through the speakers, then have it go back to playing the music. We can replace the doorbell system if needed.

The closet thing I've seen is an automatic stereo switch, but it's a one-way ticket - once the second input is activated, it leaves it on there:

http://www.amazon.com/Philips-Defini...dp/B001E1THL2/

So the needs are:

1. A doorbell system (doesn't have to be wireless) that outputs via Minijack or RCA Stereo

2. An interrupt module for muting/dimming input #1 to play input #2, then going back to input #1 at full volume

Any ideas? I've seen some high-end stuff like Viking for several hundred dollars, but she's just looking for something simple:

http://www.vikingelectronics.com/products/slp-4_tones.php

I'm thinking I may have to go with a custom Arduino solution or something, unless there's a turnkey system available on the cheap.

 

[NutBucket]

Seems to me that this would be a good homebrew project....not sure if you'll find something cheap and pre-made.

 

[Howard]

Is the ring of a fixed duration? You can take the output from the sensor, and adapt and wire it to the pause switch on the stereo system with a timer.

 

[vshah]

hmm. perhaps the guts of a harmony remote could accomplish this, if you can find an IR doorbell.

program a macro on the remote to do the following:
pause the music
ring the doorbell
restart the music.

then, tear the remote apart, hook up the button assigned to the macro to a doorbell switch, and wire up the IR transmitter to point at the stereo/IR doorbell receiver.


seems like it could be pricy though, i'm sure a homebrew method would be cheaper.

 

[Kaido]

Is the ring of a fixed duration? You can take the output from the sensor, and adapt and wire it to the pause switch on the stereo system with a timer.

It's just one of those ding-dong-ding things - there's a door contact system (magnetic, I'd assume) that sends out a signal wireless to the chime box. It can be replaced if necessary. This is the amp we'll be using, a basic 4-channel Lepai: (looks like a car receiver, but it's a desktop amp)

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=310-306

I think the interrupt would actually have to be on the speaker wire output, since the source could be onboard MP3 (USB or SD), onboard FM radio, or via an input jack from an iPod - so sometimes integrated, sometimes via minijack input. Not quite sure how that would work. I know wall-mounted volume controls can manually mute the output, so I think it'd have to be something like that.

Perhaps an Arduino module hardwired to the door sensor...use a digital potentiometer to ramp down the music, play the chime, then ramp the music back up. Seems like a lot of work for so simple a task though

 

[Kaido]

hmm. perhaps the guts of a harmony remote could accomplish this, if you can find an IR doorbell.

program a macro on the remote to do the following:
pause the music
ring the doorbell
restart the music.

then, tear the remote apart, hook up the button assigned to the macro to a doorbell switch, and wire up the IR transmitter to point at the stereo/IR doorbell receiver.


seems like it could be pricy though, i'm sure a homebrew method would be cheaper.

Yah. And I actually do have a spare Harmony remote right now.

One route I'm thinking of now is an IR blast for input switching. I think typically the radio will be used, and sometimes the front Minijack input if they want to play off an iPod, which leaves the rear RCA stereo ports free. So I could wire up the door trip system to send out two IR blasts: one to switch to the rear jacks, allow X seconds for the chime to play, then a second blast to switch back to the previous input.

Although I'm not sure how it would figure out which input was used last, plus it'd have to be line-of-site, or else wire in an IR blaster across the shop to the amp/receiver.

 

[Kaido]

One other oddball product I'm looking for - similar to the chime system...basically a wireless doorbell that plays a phone ring. Basically, it's for customers who talk a lot - when the person at the front of the shop needs an excuse to leave, they can press a button under the counter and have a phone "ring" in the back of the shop I've been looking at MP3-programmable wireless doorbells, haven't found a better solution than that yet. Maybe another Arduino project, haha.

 

[Howard]

It's just one of those ding-dong-ding things - there's a door contact system (magnetic, I'd assume) that sends out a signal wireless to the chime box. It can be replaced if necessary. This is the amp we'll be using, a basic 4-channel Lepai: (looks like a car receiver, but it's a desktop amp)

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=310-306

I think the interrupt would actually have to be on the speaker wire output, since the source could be onboard MP3 (USB or SD), onboard FM radio, or via an input jack from an iPod - so sometimes integrated, sometimes via minijack input. Not quite sure how that would work. I know wall-mounted volume controls can manually mute the output, so I think it'd have to be something like that.

Perhaps an Arduino module hardwired to the door sensor...use a digital potentiometer to ramp down the music, play the chime, then ramp the music back up. Seems like a lot of work for so simple a task though

You can use a 120VAC/12VDC relay on one of the speaker terminals, with the coil being powered by a 555 timer circuit /w trigger. When the output drops low after the timer, the coil will de-energize and the speaker circuit will be connected again. I am not certain whether you will hear "make/break" noises such as what you get when you plug/unplug a connector.

http://www.kpsec.freeuk.com/555timer.htm

The amp for the system may not like the load impedance going to infinity (open) so you might want to put a 10W-rated 50 ohm dummy load on the switched output.

 

[Fallen Kell]

Why not simply user an Arduino? You could simply wire it to the doorbell so it received a signal when the doorbell is triggered, and then have it send the IR signal to switch to another audio input for your speaker system (i.e. the "doorbell" input), and after a second or two, switch back to the music input.

Someone posted a complete guide for controlling AV gear over the web with Arduino, I am sure you can simply reuse a lot of that work and make some minor modifications to do what you want it to do (remove the web interface to the arduino, add a simple binary input (i.e. on/off), and re-code the IR output routine to send the IR signal to a remote controlled input selector to change from 1 input to another and back after a delay.

http://www.arcfn.com/2009/11/controlling-your-stereo-over-web-with.html

 

[kornphlake]

You can use a 120VAC/12VDC relay on one of the speaker terminals, with the coil being powered by a 555 timer circuit /w trigger. When the output drops low after the timer, the coil will de-energize and the speaker circuit will be connected again. I am not certain whether you will hear "make/break" noises such as what you get when you plug/unplug a connector.

http://www.kpsec.freeuk.com/555timer.htm

The amp for the system may not like the load impedance going to infinity (open) so you might want to put a 10W-rated 50 ohm dummy load on the switched output.

This is what I'd do, I might use a single shot timer relay instead of the 555 timer circuit to keep things simple.

 

[Howard]

This is what I'd do, I might use a single shot timer relay instead of the 555 timer circuit to keep things simple.

Sounds like a much simpler way to do it, thanks for the heads-up.

 

[Plugers]

This is what I'd do, I might use a single shot timer relay instead of the 555 timer circuit to keep things simple.

What about using a 555 to generate a tone and depending on the output voltage you could use a DPDT relay and switch it on the amp input side to generate a doorbell "ring" to the speakers...

Something along the lines of this: http://www.youtube.com/watch?v=1ZJOnEQgsOw

you can make different sounds though.

Solid state relays is the contacts make noise on the switchover.

 

[Kaido]

What about using a 555 to generate a tone and depending on the output voltage you could use a DPDT relay and switch it on the amp input side to generate a doorbell "ring" to the speakers...

Something along the lines of this: http://www.youtube.com/watch?v=1ZJOnEQgsOw

you can make different sounds though.

Solid state relays is the contacts make noise on the switchover.

I'm not into the electronics scene (relays & switches are all new to me!), but I'd like to get into it, and I've been wanting to try out Arduino for awhile so this may be a good first project. I think I've got the requirements down now:

1. 4 speakers
2. 4-channel amp with RCA Stereo, Minijack, SD/USB, and Radio inputs
3. Door contact switch (magnetic/reed I'd assume) to trigger doorbell
4. Emergency button to trigger fake phone call

I think a single Arduino with a Minijack or RCA Stereo output would do the trick. Multiple input methods - I'd probably do two door contact switches (front door & back door), as well as a pair of buttons - one for a fake phone call, and one to trigger a recording of voices so it sounds like there are multiple people in the back of the shop when a creepy customer comes in (happens sometimes...not a great neighborhood lol).

I found a Voice Shield that supports 4 minutes of recording time, pre-assembled for $55:

http://www.spikenzielabs.com/SpikenzieLabs/VoiceShield.html

They sell two versions - amplified and mono Minijack output. Theoretically, I could use two of them - use the mono with a mono-to-stereo splitter for the doorbell chime, and use the amplified version to a mono speaker for the fake phone call & "people noise" in the back of the store.

So now the only problem is figuring out what the last input was, so the Arduino can revert the amp back to Radio/MP3/whatever. I'll get the amp on order so I can see if it switches inputs fast enough to be viable. Otherwise it will have to be a speaker-wire interrupt system, which would be cool because it could simply "dim" the music for the doorbell.

This is getting interesting

 

[Kaido]

Some reading material:

Audio Amp Output Power Limiter:
http://sound.westhost.com/project53.htm

Arduino IR project (Speaker control):
http://forums.adafruit.com/viewtopic.php?f=25&t=26917

So one possible path is to have an IR receiver that detects the remote control input and can tell which input the receiver is on...which would work as long as they don't manually switch inputs on the receiver.

Also - rMP3 - Playback Module:
http://www.roguerobotics.com/products/electronics/rmp3

"Each module has a 1/8" stereo headphone jack for headsets (16 Ohms+) or for line-in connections. The rMP3 also has a multi-function 10-pin connector that allows direct operation of the module using simple logic triggers." That could work too.

 

[Modelworks]

I think a single Arduino with a Minijack or RCA Stereo output would do the trick. Multiple input methods - I'd probably do two door contact switches (front door & back door), as well as a pair of buttons - one for a fake phone call, and one to trigger a recording of voices so it sounds like there are multiple people in the back of the shop when a creepy customer comes in (happens sometimes...not a great neighborhood lol).

You could go through all of this, but really it is doing work for the sake of doing it as there are cheaper and easier ways of doing what you need.

1. Put a new magnetic switch on the door, not the one that the doorbell uses.
2. Wire the above switch to a low current relay.
3. When the above relay triggers it will disable the stereo
4. Relays can have dual contacts so wire the other set of contacts to the doorbell

The setup above will cause the sound from the stereo to stop, the doorbell will ring, and when the door is closed the stereo sound will return.

You can attach a second relay to the above relay so that it switches the amplifier inputs between the doorbell sound and the music playing.

The only thing left to do is get the doorbell sound through the speakers. That can be accomplished by tapping the speaker output on the doorbell wires and feeding it through a resistor and capacitor to the amplifier inputs.

Swap the doorbell and door switch labels in the picture. Slight mistake, was doing it in a hurry.

 

[Kaido]

You could go through all of this, but really it is doing work for the sake of doing it as there are cheaper and easier ways of doing what you need.

1. Put a new magnetic switch on the door, not the one that the doorbell uses.
2. Wire the above switch to a low current relay.
3. When the above relay triggers it will disable the stereo
4. Relays can have dual contacts so wire the other set of contacts to the doorbell

The setup above will cause the sound from the stereo to stop, the doorbell will ring, and when the door is closed the stereo sound will return.

You can attach a second relay to the above relay so that it switches the amplifier inputs between the doorbell sound and the music playing.

The only thing left to do is get the doorbell sound through the speakers. That can be accomplished by tapping the speaker output on the doorbell wires and feeding it through a resistor and capacitor to the amplifier inputs.

Swap the doorbell and door switch labels in the picture. Slight mistake, was doing it in a hurry.

What might work the best is to do the amp separate from the MP3/Radio system - that way there is only one input into the amp and then into the speakers, and I can do the electronics switching before the speakers ever get power. I can upgrade the amp to a TA2020+ and wire 4 speakers in parallel (they are 8-ohm), and do a few upgrades to increase the power: (better PSU + caps)

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=310-300

Then pair that with a basic FM/MP3 module with a remote control:

http://dx.com/mini-screen-free-mp3-...usb-3-5mm-audio-jack-silver-12v-91338?item=12

So then it's just a matter of a relay switching the Minijack input on the amp when the magnetic switch on the door trips. There are some cheap manual A/V switches like this one:

http://www.amazon.com/RCA-MANUAL-VID...dp/B00187P1HQ/

So perhaps...switch is tripped, relay switches to second input jack for a set period of time, plays a sound, then switches back to the first input...and since FM/MP3/etc. is all piped through there, there's no worrying about which input to switch back to. Although I'm sure there's an easier DIY way instead of using a switchbox out there.

So I need to find an FM/MP3 player that also has Minijack input for portable devices, and I also need some info on setting up a relay system & stereo switching system.

 

[Kaido]

Ah, here's a better module for $23:

http://dx.com/portable-1-4-oled-lcd...ayer-speaker-with-fm-radio-black-47751?item=2

* 3.5mm input (iPod input or whatever)
* SD/MMC & USB for MP3/WMA
* FM Radio
* Digital volume control via remote (which is great since the TA2020+ amp is manual - assuming it works on line-out)
* 3.5mm output (to amp)

 

[Kaido]

So the layout thus far:

1. Sources (Music Player + Door Switch)
2. Source Switch (based on a timered relay & chime device of some sort)
3. Amplifier
4. Speakers

So the users can use the Music Player to hookup their iPod, play off an SD/USB card, or listen to the radio. The Music Player outputs via 3.5mm output into the Amplifier, which sends the music out to the 4 speakers wired in parallel.

The piece I am now missing is the door switch interrupt system. Amazon has a magnetic door switch for five bucks:

http://www.amazon.com/Window-Contact...dp/B0056K5ZC2/

When the switch is tripped, I need to take the 3.5mm output from the Music Player, switch it to a player that plays a chime for a few seconds, then switch it back. Ideally, I'd like it to "dim" the music if that's not too hard, but a simple cutoff with a chime shouldn't be too bad - it just might be a bit of a jolt if the music is playing at a decently loud level and suddenly cuts to a chime, then cuts back again to the music.

Probably the only thing to worry about would be the volume of the chime - I'm assuming that Line Out from the Music Player is not volume-controlled (and is truly a "Line Out"), so they'll be manually making volume adjustments via the amplifier, which means the chime might be pretty loud.

So for a basic system, it looks like I'd need a timered relay, a minijack switch, and a chime player module. Suggestions welcome

 

[Kaido]

Found one for CB radios - "audio interrupt" module:

http://www.scannermaster.com/Audio_Interrupt_p/45-561488.htm

Website - http://www.audiointerrupt.com/Content/CBintercept.html

Update 1:

Found an amp for $100:

http://www.amazon.com/AudioSource-AM.../dp/B00026BQJ6

Manual here:

http://www.mcmelectronics.com/content/ProductData/Manuals/50-6062.pdf

Has two inputs - Line Input 1 and Line Input 2. Line Input 2 is the "permanent" source of sound (i.e. the Music Player), and Line Input 1 is the "priority override" source (the interrupt). The manual isn't super clear about returning to the second input after an interruption:

Line Input 1 is used to connect a local source such as a CD Player, Computer Sound Card, Television Audio Output or other line level source. Line Input 1 has "Priority" over Line Input 2 and will override Line Input 2 whenever signal is prsent at the inputs marked Line 1

But if it does return, then an audio module (driven by the door switch) could be programmed with say a 5-second chime, a 2-second silence period, and then off. So assuming it works like that, I'd need a magnetic door switch and an MP3 player module that can contain a custom recording, be switched on via a switch, and output via Minijack or RCA Stereo jacks.

Update 2:

Okay...getting a little closer here. Going back to the Arduino idea, the $55 VoiceShield has an optional Line Out version:

http://www.spikenzielabs.com/SpikenzieLabs/VoiceShield.html

So magnetic door switch to Arduino to VoiceShield to "Priority Override" amp input. Of course, now we're getting into the $200 range for everything

Another possible option with the VoiceShield is this:

All of the audio input is analog via another 3.5mm stereo jack "Audio In". Even thought the VS is a MONO device you can input stereo, the VS blends the two channels though a set of coupling capacitors into a MONO signal.

So #1, the VoiceShield can take stereo input and pump it out as mono output (which would probably be fine for a 4-speaker system - each speaker gets a blended stereo signal in mono via mono-to-stereo adapter), and #2, maybe the VoiceShield can play onboard sound *while* audio input is playing through the output. Then I could go back to the $22 amp.

My brain hurts.

Update 3:

Found a good chime module - a $15 recording module, which records up to 64 seconds of audio:

http://www.sparkfun.com/products/10653

So I can record a chime onto this device, then switch the minijack to playback mode permanently. Manual is here:

http://www.sparkfun.com/datasheets/BreakoutBoards/BOB-09579-ISD1900.pdf

One of the options is:

If PlayE is kept at Low during power turns on, the device plays message once, then powers down.

So that would work for a switched input - door opens, switch turn on the chime, then auto-powers off & returns to the permanent input jack. Assuming the $100 Amazon amp with priority override works, that would solve the problem for $135:

$5 - magnetic door switch
$15 - recording module
$23 - music player (mp3/fm/minijack)
$92 - amplifier

Update 4:

Did some more digging - found this bad boy:

http://jeffmccracken0.tripod.com/AudioBox/AudioBoxBuildProject.html

Explanation here:

http://jeffmccracken0.tripod.com/AudioBox/audiobox.html

Although it doesn't look terribly difficult to build, especially since I only need 2 or 3 inputs.

 

[Kaido]

Found a wall plate that seems to do what I want:

http://www.toaelectronics.com/mod0002.asp

For the price though ($60 - $90), I might as well get the one with the built-in amp. I still can't believe no one has an easy circuit-interrupt on the market...seems like something a lot of people would want for doorbells, intercoms, paging systems, etc. I guess that's why they charge the big bucks for them

Update 1:

What I think may be easier is to simply wire the magnetic switch to multiple bells...then we don't need an interrupt circuit, there will just be a ton of bell noise

 

[imagoon]

Found a wall plate that seems to do what I want:

http://www.toaelectronics.com/mod0002.asp

For the price though ($60 - $90), I might as well get the one with the built-in amp. I still can't believe no one has an easy circuit-interrupt on the market...seems like something a lot of people would want for doorbells, intercoms, paging systems, etc. I guess that's why they charge the big bucks for them

Update 1:

What I think may be easier is to simply wire the magnetic switch to multiple bells...then we don't need an interrupt circuit, there will just be a ton of bell noise

What you want is called a page module. Bogen [among just about every intercom company in the world] sells them.

Quick search shows this:

http://www.barcodediscount.com/catalog/bogen/zpm-3-zoom.htm

Which is way to big for you. They have a single zone one if you poke around on the bogen site.

You use a standard 24V door bell that provides audio out to it. Or you get a fancy one that just takes grounding a lead and it plays sound back that was recorded in it. Kinda like those one at stores with: "Customer needs assistance in the women's department"

 

[Kaido]

What you want is called a page module. Bogen [among just about every intercom company in the world] sells them.

Quick search shows this:

http://www.barcodediscount.com/catalog/bogen/zpm-3-zoom.htm

Which is way to big for you. They have a single zone one if you poke around on the bogen site.

You use a standard 24V door bell that provides audio out to it. Or you get a fancy one that just takes grounding a lead and it plays sound back that was recorded in it. Kinda like those one at stores with: "Customer needs assistance in the women's department"

Yeah, but even the lower-end Viking paging system mentioned in the OP is $300+, and this is to integrate a $9 doorbell. I'm surprised there's not a $10 auto-mute module available, or even a $49 ducking system.

For convenience, I may just get a multi-receiver wireless doorbell system and put the ringers in areas where employees commonly work. The next step up is to solder an auto-switch circuit, which may be pretty easy with an auto-sense wire and a timered relay. After that, I could see about doing an Arduino with something like an MP3 Trigger or VoiceShield and doing filtered pass-through with a Minijack cable. Lots of options to explore...just wish there was an el-cheapo plug & play solution

 

[imagoon]

Yeah, but even the lower-end Viking paging system mentioned in the OP is $300+, and this is to integrate a $9 doorbell. I'm surprised there's not a $10 auto-mute module available, or even a $49 ducking system.

For convenience, I may just get a multi-receiver wireless doorbell system and put the ringers in areas where employees commonly work. The next step up is to solder an auto-switch circuit, which may be pretty easy with an auto-sense wire and a timered relay. After that, I could see about doing an Arduino with something like an MP3 Trigger or VoiceShield and doing filtered pass-through with a Minijack cable. Lots of options to explore...just wish there was an el-cheapo plug & play solution

Yeah but you will spent $300 in time and parts to build your own so it is up to you if you value the experience of building it.

 

[alkemyst]

I'd do wireless that just mutes the current stereo to let the doorbell be heard.

 

[Kaido]

I'd do wireless that just mutes the current stereo to let the doorbell be heard.

Got a link to a product that has that functionality?