Finally, the Universal MP3 Sound Board Has Arrived

OK. Since the BY8001 MP3 module provides no guidance in this regard I guess it will be a YMMV.

One thing I know for certain is the MP3 processor in the module is NOT performing any kind of pre-fetch or caching of the beginning of the different MP3 files.  That is, part of the delay in starting MP3 playback is the nature of the digital compression/encoding.  I guess all you can really advise in this regard is to expect a small gap when starting/changing sounds...and to the extent possible construct the sounds to best accommodate this effect.

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Separately, for background/layout sound application I think the instructions should advise on how to wire it up to start playing upon application of power.  The closest example in the manual seems to be the Mixed-Connection diagram but that gets the trigger voltage from the +5V connector...and I don't believe the kit comes with that cable.  Plus, it's not clear/obvious if the BY8001 player module is GUARANTEED to start playing if the trigger is present upon initial powerup? 

2 other ideas on using the module:

1. Since the volume control is on the board, it may not be convenient to access in day-to-day use.  So if this is a single-sound application like for layout background, you could simply create 3 different MP3 files with the same sound at LOW, MED, HIGH volume.  Then via the remote control you can simply activate 1 of the 3 and you have remote volume control.  Ta da!

2. And related to above, you could create a "silent" MP3 sound as the 4th MP3 sound.  So if you want to mute the background sound simply press the 4th button and it will play the silent sound and stop so you have just muted the sound by remote control.

@stan2004 posted:

OK. Since the BY8001 MP3 module provides no guidance in this regard I guess it will be a YMMV.

Yep, they say absolutely nothing about transitions.

One thing I know for certain is the MP3 processor in the module is NOT performing any kind of pre-fetch or caching of the beginning of the different MP3 files.  That is, part of the delay in starting MP3 playback is the nature of the digital compression/encoding.  I guess all you can really advise in this regard is to expect a small gap when starting/changing sounds...and to the extent possible construct the sounds to best accommodate this effect.

I'm sure it doesn't.  The startup seems pretty quick, but there is a delay, I was just playing with it and watching the little LED on the MP3 module light and how long it takes for the sound to start, there is a slight delay before the sound starts after the light goes on.  The delay is well under a second, and I'm wondering if I put some WAV files on instead they'd start up faster.  They don't require the decompression, that may be one option.

(time for a test...)

I tried WAV, they do seem to start faster, almost instantaneously.  I suspect I'd have to connect the 'scope to see when the trigger and when the sound started coming out, but it sure seems faster than the MP3 file.

Separately, for background/layout sound application I think the instructions should advise on how to wire it up to start playing upon application of power.  The closest example in the manual seems to be the Mixed-Connection diagram but that gets the trigger voltage from the +5V connector...and I don't believe the kit comes with that cable.  Plus, it's not clear/obvious if the BY8001 player module is GUARANTEED to start playing if the trigger is present upon initial powerup?

You're correct, I didn't actually provide an extra cable, maybe I should add one of those in.  FWIW, I cabled the 5V to the 5th discrete input and then powered up, tried it a few times.  It always does start the sound upon startup, so there's another thing to add to the documentation.

2 other ideas on using the module:

1. Since the volume control is on the board, it may not be convenient to access in day-to-day use.  So if this is a single-sound application like for layout background, you could simply create 3 different MP3 files with the same sound at LOW, MED, HIGH volume.  Then via the remote control you can simply activate 1 of the 3 and you have remote volume control.  Ta da!

That's a good idea, and for a single use, it's a pretty effective "poor man's volume control".

2. And related to above, you could create a "silent" MP3 sound as the 4th MP3 sound.  So if you want to mute the background sound simply press the 4th button and it will play the silent sound and stop so you have just muted the sound by remote control.

I have actually used that technique a number of times, but it's useful to add it to the manual.

I really like the WAV idea.  I suppose one could also fiddle with the MP3 sampling and/or compression rate so the MP3 processor does not have to "work" as hard!  The MP3 module says:

"Supported sampling rates: 8-48K and Bit rates 8-320Kbps audio files"

And that the MP3 processor would "prefer" to decode 16-bit vs. 32-bit floating point.

I did see a significant reduction in startup time with the WAV format, it was pretty much instant.  If delay is an issue, I think that's the solution, at least the only one I can reasonably offer.

I thought about the various sampling rates for MP3, but rejected bringing that up.  If I open that can of worms, I'd get into a whole esoteric discussion about compressed audio.  I think 99% of the audience for this product would be scratching their head and wondering what I was babbling about!

@gunrunnerjohn if the J5 inputs are being used to trigger the sounds, and voltage is applied the whole time the audio is playing would that be bad?  Or does it not matter if voltage is applied to the j5 inputs for semi extended periods of time?

Use case I'm thinking about:

I'm curious if if it is bad if someone hold down a pushbutton trigger.

No problem at all, it can be there for the entire duration of the track if you like.

@gunrunnerjohn posted:

No problem at all, it can be there for the entire duration of the track if you like.

awesome!

I'm thinking then too, if you used an ASC2 to power a lionel sawmill, you could use the same wires that power the sawmill to trigger an input to play sawmill sounds. 

this little board is going to be very very useful...I've already got ideas for 3-4 more of them...

I had previously downloaded cartoon gun shots that I wanted to use for the Bugs & Yosemite Sam action car.  I wanted these sounds to trigger when Sam emerged from the top of the car.

This MP3 Universal Sound Module provided an easy method to accomplish the desired effects.

I installed the sound board in a cattle car. The open slats provided a path for the sound. I mounted the sound board vertically so that the volume control could be accessed through the open door. The trigger was accomplished with a reed switch and a magnet connected to the fifth channel. There is a one wire tether from the sound car to the action car.

The use of MP3 sound files is a feature that makes makes changing or adding sounds very easy. I loaded Christmas music to checkout the use of the remote to select other sound tracks.

Future plans for other sound tracks are to add whistle and bell sounds. I have always wanted an electronic version of the Lionel air whistle to eliminate the motor growl and the relay and motor maintenance. Another sound track could contain a message "PLEASE DON'T TOUCH THE TRAINS" to be used at train shows.

A possible idea for a future add-on board could be a timer to automatically trigger the sound tracks. The times could be user set or even an option to randomly trigger the other tracks.

@David Nissen posted:

I had previously downloaded cartoon gun shots that I wanted to use for the Bugs & Yosemite Sam action car.  I wanted these sounds to trigger when Sam emerged from the top of the car.

This MP3 Universal Sound Module provided an easy method to accomplish the desired effects.

I installed the sound board in a cattle car. The open slats provided a path for the sound. I mounted the sound board vertically so that the volume control could be accessed through the open door. The trigger was accomplished with a reed switch and a magnet connected to the fifth channel. There is a one wire tether from the sound car to the action car.

The use of MP3 sound files is a feature that makes makes changing or adding sounds very easy. I loaded Christmas music to checkout the use of the remote to select other sound tracks.

Future plans for other sound tracks are to add whistle and bell sounds. I have always wanted an electronic version of the Lionel air whistle to eliminate the motor growl and the relay and motor maintenance. Another sound track could contain a message "PLEASE DON'T TOUCH THE TRAINS" to be used at train shows.

A possible idea for a future add-on board could be a timer to automatically trigger the sound tracks. The times could be user set or even an option to randomly trigger the other tracks.

I like this.  I'm currently working on a similar project with my sound board. 

Cool, love to see the actual applications showing up!

John,

A question came to mind as I read through some of Stan's comments and your response.

Does the RF key fob transmit continuously if you hold the button down?

The jumpers you described in this table might offer different options for use with either the key fob or direct inputs.  For example, inputs held high could cause continuous play of a media file. The question there is, would the file repeat; say in the "100" option below (I note that it does NOT say "Play Once").  It also seems as though you could configure "001" to start and stop play of a media file??  Seems interesting.

Or am I totally misinterpreting?  Tx.

Yes, if you hold the button, you get continuous transmission.  You can see that looking at the LED on the receiver, it's on continuously as long as you hold the key.

By changing the jumpers on the MP3 module, you can affect the behavior of the playback.  The default shipping configuration is 010, but obviously the user can change the jumpers to select any of the options.  The 001 would indeed allow a play & stop function by repeated presses of the keyfob key.

John,
It took me some time but I have put your MP3 Sound Card to work in a project that I've had sitting around for some time.  Nothing sophisticated as far as the sound card goes.  I’m simply using the four button keyfob to trigger sounds.  Perhaps when your speed sensor card is available I might try working that in.

I installed your card in a Lionel Scale Polar Express Baggage Car.  In order to get the largest speakers I could into the car, I had to make some severe modifications to the car body and frame. I won’t show you pictures of that part as I am not proud of my abilities as a metal fabricator or model builder (some might call me a "butcher").  Suffice it to say that I had to remove the movable doors and make them permanent and cut two big holes in the frame.  I also did not reinstall the On-Off switch.  That will be a future effort.  Also, I need to find a way to blur the door windows so folks can’t just see the speakers and wires inside.

I used two 4 ohm, 3 Watt speakers wired in series.  They just barely fit in the frame.  I had to keep the plastic interior just to add some extra strength to the weakened frame.  It seems solid however.  Not vibrations that I can detect.

Everything is very roughly wired, using Wago connectors and some solder connections.  The board is velcroed to the frame so I can remove it to tinker further.

The sound you hear in the video is recorded directly from the car on my iPhone 12 Pro Max.  I prepped the audio using Audacity, mixing the original stereo source to a mono file and tinkering with compression and equalization to make the audio sound as good as it is.  I think more tweaking might yield further improvements.  The volume is set loud so that the car can be heard over running trains.  That makes it sound quite loud in a quiet room. (I have edited the video to reduce the volume)

No problems whatsoever other than me mangling one of the jumpers which caused a lost connection; easily fixed.  Just a word of caution, don't squeeze the jumpers too tightly with your needlenose.

When you have production quantities of the boards, please let me know.

Thank you for this board.  Works like dream.  Can't wait for your next products (RF switcher, Speed Sensor).  Great work.

Video of the Scale Polar Express Sound Baggage Car.  YouTube Link.

https://youtu.be/zId0z-9lCF0

Very cool Ron, great video and application! I'm impressed with the sound you were able to achieve

John,

Just a note on my experience with responsiveness of the player.  As you can see in the video above, the sound starts almost immediately after the button press.  I used a newer 32GB microSD, formatted it on a Windows laptop and put the files, individually, on the card one at a time.  I did use WAV files generated by Audacity.  The response time seems fine to me.

@FrankfordJunction posted:

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The jumpers you described in this table might offer different options for use with either the key fob or direct inputs.  For example, inputs held high could cause continuous play of a media file. The question there is, would the file repeat; say in the "100" option below (I note that it does NOT say "Play Once").

No it would not repeat.  I am not aware of any mode that would do so.  So even if the trigger is still present when a file ends, the module goes silent.  To repeat the file being played, remove the trigger and re-apply.

Depending on the application, the workaround is to simply duplicate the sound file and store multiple copies back-to-back making a gigantic file.  Very easy to do using cut-paste in Audacity or whatever.  The microSD card supplied with the module has tons of memory which translates to hours of recording time.  It really is a mindset change from the old-school sound modules that had tens of seconds or just a few minutes of storage.  In that case you definitely needed some kind of "repeat" or "loop" option to keep the sound going.

Thanks, Stan.  I suspected so.  Worth asking.  Of course, using a 32GB card, one could have days of audio to play.  Modern technology!

I figure the 1gb card is good for around 75-80 hours of MP3, maybe half that of WAV files.  However, the 32gb would good for a couple months worth of sound!

What I did for my freight car sounds was repeat the clip and make a five hour recording.  I figured I was not likely to be running for more than five hours!

Here are 4 station sounds that I have added using John’s MP3 Universal Sound Module. Very pleased with how easy it was to set up.

This is really cool.

Really nice, Captain John!!

I like the concept, execution, and the way it's been put to use.  Have to put one on my to-do list.

Have one question... The doc says that >18v will damage the board.  Since 18v is right on the edge of what is commonly used for track power, how can this be guarded against?  I saw a couple of references to a "choke" in previous posts, but I'm not familiar with the lingo - is that what protects against going over 18v?  And if so, what is a "choke"?

Thanks.

Well, 18V won't really damage the board, but there is a limit where it is too much. Note that the 18V caution applies to the sound trigger inputs.  This really comes down to the power rating of the resistors that limit current to the opto-isolators.

The limiting factor for power input voltage is really the input voltage rating of the switching power supply module, 28 volts.  So, that comes in at 20 volts AC on the track.  If you look in any Lionel locomotive manual, they say 19V, a similar rating.  If you're really worried about the maximum voltage, a few diode pairs will drop the input voltage.

FWIW, the same basic power supply circuit with the same switching power supply module has been used in my Super-Chuffer for years, and I've never had one of those go from over-voltage out of hundreds shipped and used.

The "choke" or "inductor" mentioned is to protect against degradation of the MTH DCS signal if you use this board in track powered rolling stock.

Hi JOHN,

  I am interested in one of these are they still available?  Thanks.

You know my email address.

For those that have been following along, after a period of "aging", the Wheel Speed Sensor board has been completed.  Recall that this board takes an input from a reed switch and magnet on a wheel or you can use a hall effect sensor as well.  The board outputs trigger pulses based on the speed the car is moving, that being based on the speed of wheel rotation.  As delivered, it outputs four triggers for a sound board based on speed.

• Stopped
• 0-10 MPH
• 10-20 MPH
• Over 20 MPH

Obviously, these values could change fairly easily, they're all in the on-board uP code.

One reason for the delay is I had an issue that I was scratching my head on, it turned out I was looking in a totally wrong place!  The board is supposed to power up in the stopped mode and output a pulse to initiate the stopped sound track.  That allows you to have it trigger a sound when you power up the car, even though it's not moving.  That wasn't happening, and I couldn't see why in the code!  Finally, I got it on the bench and determined that is was outputting the correct pulse, the MP3 module wasn't seeing it!  Apparently, the MP3 module needs some power up initialization and doesn't look at inputs until that's done.  Mystery solved, and now the word works as intended with the Sound Board.

Here's a typical freight car implementation with the MP3 audio board and the Wheel Speed Sensor board.  This gives you four sounds triggered as described above.  Also, I left sound #1 open, that allows you to use the RF remote for an "on demand" sound from the car and still have the track speed triggered sounds.

You'll also note that this board is powered from that optional 5V output on the MP3 board.

I created a SUB Line car.

Sounded like pretty good fidelity to me.