Exposi'Son

Additional information

A few demonstrations of what can be done with it:

• A listening post built from an old Socotel telephone, S63 or U43, on a small budget
• An audio listening post (in French) with 1 to 4 pairs of headphones (such as this one or this one plus a splitter) and up to 14 buttons
• An electronic mooing box
• My "real waterfall"
• A talking sign for a museum or a gallery
• A customer's talking sign
• A sound night light
• Sound added to a work of art
• And a billion other things...

Any kind of project is possible. Need advice (feasibility, which version to pick, how to build it, an idea, a question...)? Get in touch. And if you would like a hand with the making, my workshop is open to you.

In detail

Careful

The board is sold without a case. A case is strongly recommended, to keep anything conductive away from it, including the metal of a loudspeaker. Otherwise you risk a short circuit, and a dead board. The same goes for every similar board, such as Bare Conductive's "Touch Board", the "Teensy Audio Shield" or Adafruit's "Audio FX Sound Board".

Power

The board runs on anything between 3.2 and 5 volts, but 5 V is recommended to get the full 3 W of audio power. On its own, the board draws so little that some "smart" power banks decide nothing is plugged in and go to sleep, especially at low volume. So do test it!

USB, rechargeable cells or batteries

For the longest runtime, I recommend powering it over USB. Otherwise, use rechargeable cells. For both environmental and financial reasons, I never recommend alkaline batteries: they cost less, but they end up in the bin.

Loudspeaker or resonator?

Everyone knows what a loudspeaker is. A resonator is a kind of loudspeaker that you stick onto a solid surface (glass, wood, cardboard, plastic, and so on) and make it vibrate. That surface becomes the membrane. It is the ideal way to fill a space with sound without a loudspeaker in sight.

Expandable

The board has two screw terminals marked "1" and "2": these are "AdKey1" and "AdKey2". You can wire plenty of push buttons to them to control the player. To make that simple, I created the "Exten'Son" board, which does the job with no special knowledge required. But if you would rather do it yourself, the manual tells you how (in French).

How many boards, on which terminal, and which button plays which file? Tell me how many sounds you want and the wiring table builds itself, terminal by terminal.

One more thing

If you would like to understand how it works, head over to the manual (in French).

I designed the whole thing myself, from drawing the circuit board to soldering the components. It is made with my own hands.

So if something goes wrong, if you have a question, or if your project calls for a change, get in touch.

Technical specifications

• Choose your version and set it up, in a few questions
• Full manual (in French)
• Power, your choice of:
  • USB-C, recommended (adapter and cable, sold as an extra)
  • Micro-USB
  • Holder for AA or AAA cells (cells not included)
  • Holder for one 18650 cell (cell not included)
• Runtime (estimated):
  • USB-C: unlimited
  • Rechargeable cells: around 14 to 35 hours on the jack output / around 2 to 5 hours on the 3 W loudspeaker or resonator
  • Alkaline batteries: around 21 to 50 hours on the jack output / around 3 to 7 hours on the 3 W loudspeaker or resonator
  • 18650 cell: around 44 hours on the jack output / around 6 hours on the 3 W loudspeaker or resonator
• Audio player: a genuine DFPlayer Mini from DFRobot.
• Storage: microSD card (sold separately), up to 32 GB, formatted in FAT 16 or 32.
• Formats: .mp3 (preferably) and/or .wav (48 kHz / 16 bits maximum)
• Channels: mono (left and right mixed together)
• Playback, using the push button:
  • Every file in order, on a loop
  • The first file, once
  • The first file, on a loop
• Power and impedance:
  • 3 watts into 4 Ω, amplified, if you choose it with a loudspeaker or a resonator.
  • DAC output (not amplified) if you choose it with a jack socket. Ideal for headphones (such as this pair or this one), an amplifier, or up to 5 pairs of headphones (with a splitter).
• Volume: analogue, adjusted with a screwdriver.
• Audio outputs, your choice of:
  • 3.5 mm jack socket.
  • or a 3 watt loudspeaker (included).
  • or a 3 watt resonator (included).
• Consumption: between 10 mA and 20 mA.
• Size: 40 mm across, 20 mm thick. Mounting holes: see the last picture.
• Sensitive to damp and rain: use it indoors, or well protected.
• Handmade by me.

Sold separately (because optional)

• The "Exten'Son" board, to control it
• USB-C adapter and cable, to power it
• A microSD card, to hold your files
• Batteries or rechargeable cells: AA (formerly LR06), AAA (formerly LR03) and 18650
• A jack splitter, for up to 4 pairs of headphones.

Whatever happens

• If electronics really are not your thing, I can fit the extra buttons of your choice for you. Let's talk about it!
• If you are after a cleverer device, or a stereo one, head for my "Ambi'Son" module.
• Need a hand choosing between the two?
• If you have the slightest question, get in touch!

Pictures, videos, components, colours, version and so on: not contractual.