I have extended my arduino-audio-tools project to provide access to MP3 Meta Data. ID3 is the metadata container which is most often used in conjunction with the MP3 audio file format. It allows information such as the title, artist, album, track number, and other information about the file to be stored in the file itself. Both versions of ID3 (ID3v1 and ID3v2) are supported. I currently however only provide the information that is available in Read more…

The ESP32 Microcontroller from Espressif provides a Bluetooth A2DP functionality that can receive sound data e.g. from your Mobile Phone or send it e.g. to Bluetooth Speakers. I am providing a simple API for this in my ESP-A2DP project. Most users are using this as library in the Arduino IDE or sometimes in PlatformIO. Quite some time ago I made the project independent of the Arduino API, and now I took up the task to Read more…

Unfortunately the available memory on Microcontrollers is quite restricted and we do not get very far by storing a (uncompressed) WAV file e.g. in program/flesh memory, so I started to look into compressed audio formats. On the desktop we can use the FFmpeg project which comes with a rich set of functionality. Unfortunately the situation is much more fragmented for Microcontrollers. I started to collect the relevant libraries and in order to make things simple Read more…

Introduction I was looking for a MP3 Encoder Library for Arduino, but unfortunately did not find anything. So I decided to take this up and make LAME available as Arduino Library. LAME is a high quality MPEG Audio Layer III (MP3) encoder licensed under the LGPL. It is considered as one of the best MP3 encoder at mid-high bitrates and at VBR. I used the latest current release version 3.100 which can be downloaded from Read more…

I was struggling with an ugly problem and wished it would be possible to compile and run or debug my Audio Arduino Sketch on my Desktop Computer. So I decided to release my arduino-emulator and extend my arduino-audio-tools project and provide an example how to compile and run it in Windows, Linux or OS/X. You just need to provide an Arduino Sketch as cpp file together with this CMakeLists.txt example file. Just replace the example Read more…

In one of my last Posts I have described an approach how we can implement a simple audio output using PWM using the Raspberry Pico. The advantage of this approach is, that we can output audio to almost any GPIO pin, and that it can be used on any other processor which supports PWM. I have extended my arduino-audio-tools project to provide this functionality with a Stream based and a callback based API. The following Read more…