This is a simple basic test for the I2S output to an external DAC
We just send a generated sine wave and expect to hear a clean signal. Please note the log level should be set so that there is no disturbing output!
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)