Neural TTS on a Microcontroller ?

To produce the most natural-sounding speech, modern Text-To-Speach (TTS) systems rely on neural networks. TinyTTS is a proof of concept: It asks whether a VITS-style neural TTS model can run on a microcontroller at all. It is a header-only C++ port of tiny-tts. The model has about 1.6M parameters. It has four stages: text encoder, flow, duration predictor and a HiFi-GAN-style vocoder. There is no inference runtime such as TFLite Micro. Everything is hand-written C++ Read more

By pschatzmann, ago

AudioTools: The VideoPlayer

A follow-up to AudioTools video support, which covers container/codec selection (AVI vs. MP4 vs. MPG, MJPEG vs. H.264). This post is the other half: the pipeline that actually plays a file, a minimal sketch, and every class involved. Why this exists On a desktop, “play this video” hands the problem to an OS: a media framework demuxes the container, decodes on a scheduler-managed thread, and a compositor times frames to the display’s refresh. An ESP32 Read more

By pschatzmann, ago

AudioTools: Supporting Videos

I added video support to my AudioTools library: Different container formats can be used to store video on audio together in the same file. Here is a quick overivew of the provided functionality that is relevant for Microcontrollers: Container Formats The simplest and therefore most recommended container format is AVI (Audio Video Interleave). It is simple to both encode and decode and you can easily mix audio and video together. It supports both different audio Read more

By pschatzmann, ago

Arduino LCD TFT Boards and Material Design

Material Design is an open-source design system created by Google in 2014 to help developers and designers build consistent, high-quality digital interfaces across Android, iOS, the web, and other platforms. I did not find any existing Arduino Library which would allow me to easily implement some Material Design Applications on Arduino, so I decided to implement my own TinyMaterialDesign library. I also added a comprehensive tutorial which explains the library in detail. Further information can Read more

By pschatzmann, ago

LCD Boards with Audio

I started to work on extending the AudioTools library to support different video formats. There are quite a few boards with LDC display that have a built in support for audio output. The cool thing is that they also provide an SD drive, so that you have plenty of room to store audio and videos. In a first step, I tested the audio and the LCD output. Here is an overview of the boards that Read more

By pschatzmann, ago

Receiving Audio via USB: a Deep Dive

In one of my last blogs, I gave an overview of the USB Class 2 Audio functionality provided by the AudioTools library Many users were struggeling to get the process of receiving data via USB and writing to I2S stable and working properly. In this blog I am providing a deep dive of the releated challenges and the solution approaches: Standard Processing Logic Here is a simple basic sketch that demonstrates the standard processing logic: Read more

By pschatzmann, ago

Microcontroller FFT & IFFT Performance Benchmark (N=64)

The Fast Fourier Transform (FFT) is an efficient algorithm for computing the Discrete Fourier Transform (DFT): it converts a signal from the time domain into the frequency domain, revealing which frequencies are present in a signal and how strong they are. It is the workhorse behind spectrum analyzers, audio effects, filtering, and countless other DSP applications. I recently published a new FFT library that supports both integer and floating-point data types for its calculations. Using Read more

By pschatzmann, ago

USB Audio Class 2 for STM32 Arduino

In my last blog, I described my USB Audio Class 2 implementation. I was wondering if this functionality can also be used for STM32 micocontrollers. Since the solution relies on the Adafruit_TinyUSB_Arduino library, I was running into the issue that there is only a preliminary support for STM32-F4 micocontrollers. I decided to exend the support for the STM32-F7 and  STM32-H7. You just need to install corresponding stm32 branch from my fork e.g  with cd ~/Documents/Arduino/libraries Read more

By pschatzmann, ago

USB Audio Class 2.0 for Arduino

I’m happy to announce that the Arduino Audio Tools library now includes native USB Audio Class 2.0 (UAC2) support. Your ESP32-S3 or RP2040 board can show up as a standard USB microphone, speaker, or both — no drivers needed on the host side. Linux, macOS, and Windows 10+ recognize it out of the box. Why USB Audio? Most Arduino audio projects use I2S to talk to an external DAC or ADC. That works well, but Read more

By pschatzmann, ago

MP3 Encoding for Microcontrollers (using Shine)

Quite some time ago, I published a blog about using LibLAME as a library to encode PCM audio data to mp3 using a micro-controller. Yesterday I was asking ChatGPT about this topic and it recommended the Shine MP3 encoder. So I took up the task to provide an Arduino compatible Shine Library and integrate it into my AudioTools. Here is a related Arduino test sketch that measures the encoding perfrmance for 44100 stereo audio data Read more

By pschatzmann, ago