Play audio on an ESP32 or an Arduino

Question

I am in the process of making a talking robot and I have linked my ESP32 to a Google text-to-speech service. The service returns me a base64 8-bit audio response.

I need to play this audio and I can't figure out how to do it. I know that an audio playing library exist for PCM but the data that it requires is not base64.

• Majenko: Base64 is just an encoding to encapsulate 8 bit data into ASCII text. It has nothing to do with audio. Decode it first into your binary data then use a suitable library for your hardware to play it.
• Adriano: On the esp, there is also an offline version of text to speech. Just if you want to try it...
• Avon97: I don't know weather this will help you there is a guy who makes cool stuff in GitHub text to speech in esp8266 hope it will work in esp32 too github.com/earlephilhower/ESP8266SAM

Answer 1

Base64 has nothing to do with audio. It is merely a way of encapsulating binary data into ASCII text so that it can safely be included in text-based structures like JSON, or transmitted over a text-based communication channel.

There is no library to "play" base64 simply because base64 is not something you play.

First you decode the base64 text into raw 8-bit binary. It's then that data that you play through whatever library is most suitable for your hardware.

For example on the ESP32 you have the function base64_decode() available. You can read up on how to use it in this tutorial.