54 lines
1.8 KiB
Markdown
54 lines
1.8 KiB
Markdown
# A Simple Callback Audio Player
|
|
|
|
The example demonstrates how to implement an __MP3 Player__ which __provides the data via callbacks__ and sends the audio via I2S to an external DAC.
|
|
|
|
This demonstrates the minimum implementation. I recommend however to provide implementations for the other callback methods to enhance the functionality: e.g absolute positioning, file selection by name etc.
|
|
|
|
|
|
## SD Card
|
|
|
|
Here is the information how to wire the SD card to the ESP32
|
|
|
|
| SD | ESP32
|
|
|-------|-----------------------
|
|
| CS | VSPI-CS0 (GPIO 05)
|
|
| SCK | VSPI-CLK (GPIO 18)
|
|
| MOSI | VSPI-MOSI (GPIO 23)
|
|
| MISO | VSPI-MISO (GPIO 19)
|
|
| VCC | VIN (5V)
|
|
| GND | GND
|
|
|
|
|
|
### External DAC:
|
|
|
|
For my tests I am using the 24-bit PCM5102 PCM5102A Stereo DAC Digital-to-analog Converter PLL Voice Module pHAT
|
|
|
|
|
|
|
|
I am just using the default pins defined by the framework. However I could change them with the help of the config object. The mute pin can be defined in the constructor of the I2SStream - by not defining anything we use the default which is GPIO23
|
|
|
|
|
|
DAC | ESP32
|
|
-----|----------------
|
|
VCC | 5V
|
|
GND | GND
|
|
BCK | BCK (GPIO14)
|
|
DIN | OUT (GPIO22)
|
|
LCK | BCK (GPIO15)
|
|
FMT | GND
|
|
XMT | 3V (or another GPIO PIN which is set to high)
|
|
|
|
- DMP - De-emphasis control for 44.1kHz sampling rate(1): Off (Low) / On (High)
|
|
- FLT - Filter select : Normal latency (Low) / Low latency (High)
|
|
- SCL - System clock input (probably SCL on your board).
|
|
- FMT - Audio format selection : I2S (Low) / Left justified (High)
|
|
- XMT - Soft mute control(1): Soft mute (Low) / soft un-mute (High)
|
|
|
|
|
|
|
|
## Dependencies
|
|
|
|
- https://github.com/pschatzmann/arduino-audio-tools
|
|
- https://github.com/pschatzmann/arduino-libhelix
|
|
- https://github.com/greiman/SdFat
|