# EZ MP3 Automation



## toddalin (Jan 4, 2008)

I bought an MP3 player, and amp with speakers, and a solonoid to assemble a poor man's sound system. This is for the Lowrider train and it will play The Lowrider by War. All parts are from Allelectronics.com.


























But the question becomes how do you start/stop it?

Voila!


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## toddalin (Jan 4, 2008)

I finished the MP3 system, except for making a front cover. (I don't know where the old one ended up.)


Anyways, I got everything to fit in a 6.25" x 3.75" x 2" box that will fit inside the AristoCraft small freight station where the Lowriders park.


There is a trick to getting it to work reliably. The solenoid develops maximum force just before bottoming out, and it takes all of this force to reliably push the button on the MP3 player each time. So theoretically, you want to put the MP3 player at the bottom of the travel with just enough travel to overcome the friction of the button. This works fairly well, if given a nice kick as you get using track power. But it is not 100%.


What we need to do is to give the solenoid a "running start" when it pushes the button. A plastic collar from ??? was CA'ed onto the solenoid shaft as was a Kadee coupler spring. The spring extends


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## Dansgscale (Jan 9, 2010)

Tod: interesting use of cheap MP3 parts. I was wondering why did you go to all the trouble of using a solanoid to push the button instead of opening the sace and wiring a 5 or 12 Volt relavy straight to the button and then use your 555 to activate the relay. 

I use a simular setup for playing the R2 sounds in a Full size droid I built. I use a cheap A## $5.00 USB MP3 player that just loops the audio files. To start the player I tapped into the push button and soldered two wires to it and then connected them to the relay contacts that are on a Small R/C switch that is pluged in the the R/C Receiver. So all I have to do it flip a toggle switch on the transmitter and I can activate the sounds. 

I have used this same method in one of my Sound Boxcars, but I have it wired though a 12 Channel RF Relay board, so I can activate a Bell, Whistle and escaping steam on three different sound modules. I have been working on using a 433 MHZ RF transmitter and Receiver Modules and then connectng the receiver to a PICAXE Micro Processor and then to the sound modules and eliminate the Relay board all together. That way I can write a simple basic program and tell the Micro what to do when I press one of the 8 buttons. That way I can have it play the whistle sound, or the bell or the stram exhast or any combination of the three. Each sound module has its own 2 watt amp using a LM386 chip with volume control as well as it's own small speaker, that way I can adjust each one of them so they sound harmonious together. 

Dan S. 
Colorado and Rio Grande Southern 
http://danshobbies.webstarts.com/index.html 


Does your MP3 player have a builting AMP or are the speakers amplified?


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## toddalin (Jan 4, 2008)

Posted By Dansgscale on 25 Jul 2012 04:47 PM 
Tod: interesting use of cheap MP3 parts. I was wondering why did you go to all the trouble of using a solanoid to push the button instead of opening the sace and wiring a 5 or 12 Volt relavy straight to the button and then use your 555 to activate the relay. 

I use a simular setup for playing the R2 sounds in a Full size droid I built. I use a cheap A## $5.00 USB MP3 player that just loops the audio files. To start the player I tapped into the push button and soldered two wires to it and then connected them to the relay contacts that are on a Small R/C switch that is pluged in the the R/C Receiver. So all I have to do it flip a toggle switch on the transmitter and I can activate the sounds. 

I have used this same method in one of my Sound Boxcars, but I have it wired though a 12 Channel RF Relay board, so I can activate a Bell, Whistle and escaping steam on three different sound modules. I have been working on using a 433 MHZ RF transmitter and Receiver Modules and then connectng the receiver to a PICAXE Micro Processor and then to the sound modules and eliminate the Relay board all together. That way I can write a simple basic program and tell the Micro what to do when I press one of the 8 buttons. That way I can have it play the whistle sound, or the bell or the stram exhast or any combination of the three. Each sound module has its own 2 watt amp using a LM386 chip with volume control as well as it's own small speaker, that way I can adjust each one of them so they sound harmonious together. 

Dan S. 
Colorado and Rio Grande Southern 
http://danshobbies.webstarts.com/index.html 


Does your MP3 player have a builting AMP or are the speakers amplified? 


Thanks Dan,

I have done it as you suggest for other projects and the Del Oro Pacific module in the past, but the the "guts" of this MP3 player really didn't allow for this. To access the tiny membrane switch leads would require a total disassembly of a partially sealed unit which would in all probablity destroy it. Sometime you have to know your limitations and work within them.

One of the speaker enclosures includes the amplifier. The MP3 player will drive a headphone.


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## Dansgscale (Jan 9, 2010)

Todd: That answered my question completely. Sometimes they just make cool stuff just too darn small to work with and you have to figure a work around. Your use of the solanoid did the trick. 

I'll have to take a look at the latest All Electronics Catalog for those speakers and MP3 player. 

Dan S. 
Colorado and Rio Grande Southern 
http://danshobbies.webstarts.com/index.html


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