uMP3 triggger Demo
This is a quick demo of the uMP3 being used to play sound effects for a prop or haunt. It is designed to play an "ambient" loop of spooky music until it detects a trigger. At that point it jumps to that sound effect. Depending on how you configure the program, you can have the triggered sound either stop when the trigger is released, or continue to play (ignoring other triggers) until it concludes. Either way, when the triggers are released the system returns to the ambient sound loop.

To build/test this project you will need:

1. One Parallax Basic Stamp II
2. A Basic Stamp carrier board (optional, depends on the stamp)
3. The Parallax Basic Stamp Editor on a computer
4. A Serial cable to download programs to the BSII
5. One Rogue Robotics uMP3 player
6. One SD/MMC memory card for uMP3
7. Headphones or a small audio amplifier for the uMP3

• Pin 2- connected to N.O. pushbutton to GND (pulled high)
• Pin 3- connected to N.O. pushbutton to GND (pulled high)
• Pin 4- connected to uMP3 "T" communication port
• Pin 5- connected to uMP3 "R" communication port

1. Connect a small resistor (~100k) between pin 2 and 5v+
2. Connect a small resistor (~100k) between pin 3 and 5v+
3. Connect a N.O. pushbutton between pin2 and GND.
4. Connect a N.O. pushbutton between pin2 and GND.
5. Connect Pin 4 on the stamp to the "T" connector on the uMP3.
6. Connect Pin 5 on the stamp to the "R" connector on the uMP3.
7. Make sure the uMP3 and the BSII are connected to a 5v supply with a common gnd between them.
8. Load the following sound files onto the ROOT (i.e. not in a subdirectory) of your SD/MMC card:
   
   • Dramatic-Cue-EndingHit-0.mp3
   • Dramatic-Reveal-Horns1.mp3
   • Dramatic-Cue-Fast-0.mp3
   • Suspense-Queue-0.mp3
   
   
9. Load the uMP3-TriggerDemo2c.bs2 into your stamp editor.
10. Read the code and the comments! There is information on how to make sounds play only for the duration of the trigger or have stamp wait for a sound to finish before going back to the "ambient" loop.
11. Download the code to your stamp

The ambient sound should start playing immediately. Pressing either of the buttons should cause the system to "jump" to the associated sound effect. Pressing both buttons gives a third sound effect. Depending on the code, the sound will return to the "ambient" loop either when you a) release the trigger button or b) when the sound is finished playing.

As I explore this cool little board in more depth, I expect I'll be adding more to this site. Also, if you have a uMP3 and would like to ask questions or share your ideas, please feel free to send an email to vern@txis.com.