WAV Trigger: One Sound FX card to rule them all - Embedded.com

WAV Trigger: One Sound FX card to rule them all

My dreams have been answered. I am currently performing my happiest of happy dances (it's not a pretty sight). Let me explain. For the longest time, I've been looking for a sound effects card to use in my hobby projects. In the case of my Inamorata Prognostication Engine, for example, the front panel is festooned with antique push-buttons and toggle switches and knobs and dials. When I flick a switch on this little beauty, I don’t want to be disappointed with a sheepish “click” that sounds embarrassed to be making itself heard. My ears deserve to be caressed by a satisfying “ker-thump,” followed by the sounds of clockwork contrivances and mechanical mechanisms and balls rolling down chutes and suchlike.

Sad to relate, I couldn’t find anything to fit the bill. For some applications synthesized sound might be the way to go, such as the effects one can obtain using a GinSing Shield, for example.

In the case of my projects, however, I want to use real-world sound samples, so next I looked at traditional audio shields such as the WAVE Shield from Adafruit.

The WAVE Shield is described as being ideal for adding audio effects to one's projects. The problem is that — like the vast majority of cards of this ilk — it can only play a single audio file at a time. For my projects, by comparison, I want to be able to add “layers of sound” corresponding to different actions taking place.

Eventually, a group of us started to consider designing and building our own card, as discussed in Sound Effects Shield for Arduino: The Specification. This project has been shuffling along in the background, but everyone is busy and nothing really substantial has emerged.

And then, just a couple of days ago, my chum Duane Benson sent me an email saying:

I've been busy getting ready for Maker Faire and haven't had time to work on our sound player, but this sound effects board may be what we're looking for.

“This” turned out to be the WAV Trigger board, which is supplied by our friends at SparkFun, but which was actually created by my new hero Jamie Robertson, who is a senior Disney Imagineer by day and a mad scientist designer by night (check out Jamie's Robertsonics.com website).

OMG! As I said at the beginning of this column, the WAV Trigger board is the answer to my dreams. The key feature is that it's Polyphonic , which means “many-voiced” or “capable of producing many sounds simultaneously.” In fact, the WAV Trigger can play and blend up to 14 stereo audio streams at the same time, where each stream can be started, paused, resumed, or terminated independently. The board also automatically performs voice stealing, which means that — if it's told to play a new audio stream while it is currently playing the maximum number of streams — it will automatically drop the oldest audio stream and add the latest request to the mix.

The way this works is that you use an audio editor like Audacity to prepare your sound snippets on your host computing platform (Windows, Linux, etc.). You can use your own sound bites and/or you can download them from loads of websites. Then you copy these sound files onto a Micro-SD card, which you plug into the WAV Trigger board.

The board I have supports up to 1,000 uncompressed 16-bit, 44.1kHz stereo WAV files (CD-quality), which is way more than I personally need, especially remembering that I only require short sound snippets and an 8GB Micro-SD card can hold over 12 hours of stereo WAV audio. (I was chatting with Jamie on the phone earlier, and he is currently working on a new version of the firmware that will support up to 2048 tracks.)

The simplest way to use the WAV Trigger is by means of its 16 trigger inputs, which can be set to be edge or level sensitive, and which can be controlled by simple switches or by a microcontroller. In this case, activating a trigger input will cause a corresponding audio file to be added into the mix (the trigger-to-sound delay is typically only 8 milliseconds). Alternatively, you can control the WAV Trigger using a simple serial protocol — an Arduino Library is available to make this easy — that allows you to access all 1,000 sound files. But instead of my waffling on, check out This Video and tell me what you think.

I can’t help myself. I'm currently chuckling and chortling with delight. My WAV Trigger is sitting here on my desk looking up at me with a “hello handsome, are you ready for some fun” look (metaphorically speaking). What can I say? Yes, I am indeed ready for some fun. Watch this Embedded.com space for future updates as I integrate WAV Triggers into all of my projects.


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18 thoughts on “WAV Trigger: One Sound FX card to rule them all

  1. “Hey – thanks for the write up! I should point out to your readers that the video above was done for the original release of the board some time ago. Since then, the polyphony has increased to 14 stereo voices, latency dropped to around 8ms, and I've added

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  2. “Hi Jamie — maybe it's time for a new video LOL Speaking of which, I love the links to the videos you sent me of the user projects using the WAV Trigger — I'll post them here as comments tomorrow.”

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  3. “FYI: The 6-pin serial connector on the WAV Trigger is designed to be pin-compatible withe the FTDI Basic. Install either a straight or right-angle male header and you can plug the FTDI Basic right in. Close the WAV Trigger 5V solder jumper and the FTDI Ba

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  4. “Since I'm planning on using WAV Trigger boards in pretty much all of my projects, I'm going to order a bunch of these connectors today.”

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  5. “Nice Job, Jamie- I'm sure I'll be using the WAV trigger in some of my projects real soon!nnMax- Thanks for letting us know about this cool device. I'm eager to see how your projects incorporating this goodie turn out! I'll start keeping an eye out for s

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  6. “Hi Rick — when are you next planning on visiting Huntsville — if you give me a heads-up, I'll make sure to have the card here to show you.”

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  7. “I was just on Jamie's website, and saw the mention of a project to restore a Mellotron M400. Wow! That brings back memories! Just after High School I worked at a recording studio that had an M400 with several tone banks, including one for strings. The loc

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  8. “Hi Rick — I love the sound of the Mellotron — Jamie's video of this soundcard makes me want to run out and buy a keyboard right now. “

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  9. “Hi Robert, nThe WAV Trigger sounds great, I've never used this kind of technology before but I want to give it a go! Would you be able to inform me as to whether I could link motion sensors to it to trigger the sound instead of a keyboard? And can the WA

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  10. “Hi there — Max here — I'm not an expert, but you could certainly use motion or other sensors to trigger the sounds — in some cases you could connect them to the WAV Trigger's inputs directly — or it may be that you want to use an external micro (like

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  11. “This is a brilliant board, I've just bought a couple of them for audio installations for theatre projects. Keen to rig a couple of sound boxes in trees so sfx are triggered by an audience walking past- can anyone point me in the direction of a simple PIR

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  12. “Hi Hoop-nIt shouldn't be a problem to connect a Passive Infrared (PIR) motion detector sensor to the WAV trigger. Go to Sparkfun, Adafruit, or Parallax websites and do a search on “PIR”. Most of these modules operate on 5 to 12 volts and have an oputp

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  13. “Hi Joe — Rick Curl posted a comment about this elsewhere in this thread, in which he said:nnIt shouldn't be a problem to connect a Passive Infrared (PIR) motion detector sensor to the WAV trigger. Go to Sparkfun, Adafruit, or Parallax websites and do a

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  14. “Hello,nI plan to test the robertsonics board ! nThe only shame in this device is I cannot access the SPI card from an other like arduino. nnI do not need necessary the low latency, does anyone consider to install polyphonic plugin in the yun arduino o

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  15. “Awesome little board Max and I can see why it makes you do your happy dance. Jamie obviously knows his Audio. I was also interested to look at the other boards you mentioned. I have been thinking about building myself a new audio system, but I'd like i

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