Esp8266 Music Machine

After months of esp8266 experimentation, I “just” discovered this little chip has also a I2S Audio digital interface. To discover it you must install the Arduino IDE adapter and code directly in C++ (brr, ok not a breeze but not boring like Java :)

I2S is a digital protocol to send your digital  music to a DAC decoder. Esp8266 has a 16bit DAC.

The ESP8266Audio library is a very powerful and dynamic library. You can play a lot of file formats.

The clever part of this library is you need not a DAC circuit: the library come with a delta-sigma DAC emulator, to use a simple transistor to power an analog speaker.

A delta-sigma DAC encodes a high-resolution digital input signal into a lower-resolution but higher sample-frequency signal that is mapped to voltages, and then smoothed with an analog filter. In both cases, the temporary use of a lower-resolution signal simplifies circuit design and improves efficiency.

(From Wikipedia)

To understand Delta Signma look at this article https://hackaday.io/project/6356-delta-sigma-versus-pwm

I just joined this library with the makeEspArduino Makefile, to get a fast compilation cycle.

This because Arduino compilation slow down a lot with this library (it seems to need a huge set of libraries).

Anyway, a very good library you should give a try!

 

References