So far I have always used the Arduino loop to do the audio processing with the hint, that there must not be any longer delay added to the processing. If you have some blocking functions in the loop, the solution is to run the audio in a separate task. I Read more
I am providing an Arduino MP3 and AAC decoder library for Arduino which is based on libhelix. In this library I added a simple Arduino inspired C++ API. This was one of my first libraries and I found my implementation quite confusing. So it was time to do some refactoring Read more
There are some DACs out there that only support 32 bits: E.g the ES9018K2M module which is sold as high end HIFI DAC. Therefore sometimes it is necessary to change the sample size e.g. from 16 to 32 bits when your codec produces 16 bits. This can be easily done Read more
Mozzi brings your Arduino to life by allowing it to produce much more complex and interesting growls, sweeps and chorusing atmospherics. These sounds can be quickly and easily constructed from familiar synthesis units like oscillators, delays, filters and envelopes. One of the strong points of my AudioTools library is, that Read more
Recently there was a discussion on how to output more then 2 channels via I2S. I2S is limited to 2 channels, but the ESP32 has 2 I2S ports, so we can output a maximum of 4 channels! Arduino Sketch I have added a small example that shows how this can Read more
Mozzi brings your Arduino to life by allowing it to produce much more complex and interesting growls, sweeps and chorusing atmospherics. These sounds can be quickly and easily constructed from familiar synthesis units like oscillators, delays, filters and envelopes. Mozzi supports quite a lot of different Micro controllers, but it Read more
Arrays The best way to allocate an Array of data in the AudioTools is by using a Vector. E.g. Vector<int16_t> vector{100000}; is allocating a vector of 100’000 2 byte signed integers. RAM and PSRAM The ESP32 has a few hundred kilobytes of internal RAM, residing on the same die as Read more
Pure Data (or just “Pd”) is an open source visual programming language for multimedia. Pure Data is developed by Miller Puckette since 1996 and you can find it on his official website along with the official documentation and other related resources. I wanted to have the possibility to run PD Read more
Quite some time ago, I demonstrated how you can send Audio to your mobile phone using the VBAN protocol. Recently I have added support for receiving data to your microcontroller as well. With this you can use this protocol to build some cool two way communictations applications (e.g. walkie-talkie). Arduino Read more
In my last post I have complained that my sine wave test sketch was producing just noise. So I am trying now to investigate where the issue is coming from. Using Basic APIs So first, I try an Arduino Sketch which is just using the low level API of my Read more