So far I have created quite a few posts about the supported codecs, but I never provided any detailed information how things work behind the scene. Audio codecs are used to compress and decompress PCM audio data. I tried to eliminate all the complexity but sometimes it helps to know Read more
We can dynamically allocate memory with malloc() or use the dedicated ESP32 specific functions. In general we need to use byte aligned allocations (MALLOC_CAP_8BIT). When we have used up all available memory space, we still have 4 byte aligned memory available that we can use to store arrays of int32_t Read more
Quite some time ago, I was describing how we can stream audio with the help of RTSP. In that example we needed to provide a data stream from which we can read the audio! This is not very flexible and often we want to specify RTSP as output: e.g. in Read more
I am currently providing quite a few audio processing classes which can be used to change the audio format. So far, the FormatConverterStream could be used to change the bits_per_sample and the number of channels only. I thought it might be cool, if we could use this class for changing Read more
I have extended the I2S interface in Mozzi, so that we can can use the getAudioInput() which reads the audio via I2S: This can be used e.g. by the AudioKit. Until this change has been merged, you need to use my extended project. Mozzi brings your Arduino to life by Read more
In the old days I was rather a Commodere PC guy, but I know of colleagues of mine that were addicted to the Commodore 64 and knew it inside out. So, here is another project that makes you feel nostalgic: Sound Interface Device (SID) is a audio format used by Read more
I thought it might be interesting to compare the Rasperry Pico W with the ESP32. While the ESP32 provides faster numeric operations, I did not have any visibility how these two microcontrollers compare in regard of the WIFI speed. The good news is, that the URLStream from the AudioTools library Read more
Recently somebody asked me to provide some pink noise! I knew about white noise, but I did not know that noise can come in different colors. So this is the perfect opportunity to play around with noise.
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. The AudioKit is a cheap ESP32 based audio board that usually Read more
I have added a simple output class to my Arduino Audio Tools which can display the result of a FFT analysis on an LED Matrix. For my tests, I am using a 32 x 8 LED Matrix, but first we need to test the functionality. Determine the Wiring Logic I Read more