We've made a bunch of things today, let's take a look.
The component list was updated today (03/24/2017) here are some explanations about what you need to create this project at home. Please note that all the components are still on a test phase and won't all be used. This list will obviously be updated so stay tuned folks !
Micro controller : Adafruit Pro Trinket - 3V 12MHz or Adafruit Trinket - Mini Microcontroller - 3.3V Logic
Both were chosen because of their size, they'll make easier the final integration on the bracelet. However they are still very powerful and can be almost coded like a classic arduino. The main difference between the Pro Trinket and the Trinket Mini is the size, and so the CPU attached on those. Maybe the mini specs (ATtiny85, 8K of flash, 512 byte of SRAM, 512 bytes of EEPROM) will be a bit low, but we will see in a few weeks !
Electret Microphones : Adafruit MAX4466 or MAX9814 or SPW2430
Several ones were chosen, because we are afraid of saturation and resolution. We don't want the mic to be saturated at 100dB for example. It would be a shame because we want to detect the sound up to 130dB at least. The MAX4466 is quite classical and has an integrated op-AMP and gain can change from 25x to 125x while the MAX9814 has an automatic gain control. However "max gain" can obviously me modified. Finally the SPW2430 is the smaller one and probably the best for audio detection while the two previous ones can be used for recording/sampling - but "the output peak-to-peak voltage has a 0.67V DC bias and about 100mVpp" - so it's the more likly to clip/sature on high-level sounds. So at this point we don't have any favorites !
First of all we wanted super tiny and basic leds but then we moved to adafruit's Neopixels. They are way much bigger than what we looked at the beginning but they are also way much cooler because you can change color and use a Bus to control them, it means less wiring and we love that !
Feel free to take a look at our schedule, so you won't miss any updates. They'll be mostly posted every wednesday, when we are at the CRI Paris, France.
Bertrand started working on the code, he'll use or at least fin inspiration on the following one wich was created by adafruit (them, again). It's quite close from what we're trying to do, but in a different way and with different objectives (however this is a rad tie).
Adafruit related project : https://learn.adafruit.com/led-ampli-tie/overview
Here is the raw code (our's will be a lot easier)
Read more »