ESP32 Soundboard
================
Soundboard (computer program), a web application or computer program with buttons that play short, often humorous sound clips.


## Hardware
* [ESP32] µC
* [MAX98357A] PCM Input Class D Audio Power Amplifiers
* [SD card]


## Wiring

### SD card
SD card pin   | ESP32 pin     | Notes
--------------|---------------|------------
CS            | GPIO05        |
DI            | GPIO23 (MOSI) |
SCK           | GPIO18 (SCK)  |
DO            | GPIO19 (MISO) |
CD            | GPIO17        | optional

### Touch
ESP32 Touch pad | GPIO | Notes
----------------|------|-------
T0              | 04   |
T1              | 00   | also bootloader (not usable on dev board)
T2              | 02   | also bootloader (not usable on dev board)
T3              | 15   |
T4              | 13   |
T5              | 12   |
T6              | 14   |
T7              | 27   |
T8              | 33   |
T9              | 32   |

### I2S
MAX98357A | ESP32 pin
----------|-----------
LRC       | 25
BCLK      | 26
DIN       | 22
GAIN      | (VCC)
SD        | -


## Build
```bash
git clone https://dev.xd0.de/hendrik/soundboard.git
cd soundboard
virtualenv .
source bin/activate
pip install -U platformio
platformio run -t upload && platformio device monitor -b 115200
```

* Convert mp3 files: `sox ~/Music/input.mp3 -c 1 -r 11025 output.wav trim 0 30`
* SD card is tested with one FAT16 partion

## ToDo
* Prototype
* reimplement tasks with a queue, see **i2s_push_sample()** from *esp-idf/components/driver/i2s.c*
* Keypad layout
* internal DAC?
* Add-ons?
* dynamic keypad thresholds
* wav file headers
* stack size in play task

## References

[ESP32 overview]: http://esp32.net
[ESP32]: https://eckstein-shop.de/ESP32-Dev-Board-WiFi-Bluetooth-CP2102-USB-to-Serial-with-LiPo-charger
[MAX98357A]: https://eckstein-shop.de/Adafruit-I2S-3W-Class-D-Amplifier-Breakout-MAX98357A