I thought it should be quite easy to use the new debugging functionality of Arduino 2.0 with the RP2040 using the official RP2040 debug probe in Earle Phil Hower’s core. I am using Arduino on my old Macbook running Linux: And Boy was I wrong! The first challenge was to Read more…
At the very beginning of my Arduino AudioTools project, I was providing a codec for WAV files. It was just handling PCM audio, so it just needed to read or write the header and then could just copy the audio data. In my last blog, I was writing that the Read more…
My AudioTools project is supporting quite a few audio encoders and decoders. They are critical to reduce the storage or transmission volume of audio. Though I support the encoding of AAC and MP3, I can’t really recommend this: it requires a lot of memory and processing time. For an introduction Read more…
In my last post I was writing about audio containers. But containers are usually also used to mux audio and video together in one file. This made me think, if we could play movies on an ESP32? In fact there are some projects out there that exactly do this: They Read more…
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…