Custom Car Horn Control Box V2

This control box adapts the tutorials for custom car horns to work with a generic audio playback module instead of an Adafruit playback module.  The main benefits of using a generic module is that the amplifier is built in, helping to shave $30-$40 off the overall project costs.  You lose two button inputs (11 → 9), but in my opinion this is still plenty for the job.

There are multiple versions of the controller available

• V1: The original design, with a button panel on the front of the control box.

• V1.5: The original design, but with a handheld button pad added.  The button pad snaps onto the top of the control box if magnets are utilized.

• V2: A redesign of the control box that drops the front panel, resulting in a sleek design that is easier to mount out of the way.  A custom box 

Screws

• 2x M3 x 8mm (all models)

• 2x M3 x 25mm (V1 or V1.5)

• 4x M3 x 16mm+ (V1 or V1.5)

• 2x M3 x 16mm (V1.5 or V2)

• 2x M3 x 30mm (V2)

Common parts

• Cigarette lighter to bare wire

• Speaker 

  • This one is plenty loud - people will hear it through walls at full volume.

• 10k potentiometer 

  • Run the wires from the potentiometer onto the pins below the playback module's built-in potentiometer (this is your volume knob).

• Audio playback module

  • SD card versions are ideal for replacing audio files

• Micro SD card with 1GB-32GB space

  • Only needed if you get the SD card playback module

• Lots and lots of wire 

  • 30 feet (10 meters) for the controller

  • 3-9 feet / 1-3 meters for the power wire (depending on placement)

Specific parts

• 50mm x 70mm prototyping board (for V1 or V1.5 controller)

• Push buttons (for V1 or V1.5 controller)

• Push buttons (for V1.5 or V2 controller)

• Magnets (for V1.5 or V2 controller)

Sound effects

Make sure that your audio files are labeled 00001.mp3 through 00009.mp3 on the SD card - they cannot be contained inside any folder or .zip file.  Several .zip files for sound effects are included with properly-formatted and named audio files.  

Demo of the V1 controller wired up