In my last blog, I described the analog audio output using the Arduino Audio Tools library: The STM32H743VIT6 microcontroller is quite powerful but we only have max 2 DAC pins available! This restriction falls when we use PWM: We use a PWM frequency above the hearing range (30khz) and modulate Read more…
In my last post, I have introduced you to the powerful STM32H743VIT6 microcontroller. Now it is time to test some audio output. I don’t have any special implementation for the output of analog audio for the STM32H7, but I decided to try to use my generic implementation that is part Read more…
There are different cheap but powerful Chinese development boards with different STM32H7 chips from DevEBox and WeAct. STM32H750VBT6 – 128K flash STM32H743VIT6 – 2048K flash I recommend to use the STM32H743VIT6 with the 2MB of flash memory. Please note that this is still only half of what you get with Read more…
Currently it is already possible in the Arduino AudioTools Library to define some processing chains: Audio Objects are connected to other objects e.g. by adding the dependent object as parameter in the constructor. Since the very beginning of the library, I planned to have some Pipeline class that would help Read more…
I am providing a Bluetooth A2DP audio library for the ESP32, which can receive audio from a Bluetooth Source (e.g. a mobile phone) and play it via the I2S API provided by the IDF framework. Unfortunately Espressif has decided to go for a completely new I2S API which means that Read more…
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…