Implementing a Synthesizer for the Raspberry PI and the ESP32 – Introduction

Overview I was playing with the idea to implement a simple Synthesizer for the ESP32.which would play different instruments. The ESP32 should have enough power to generate interesting sounds. The limitation however is on the memory.  So any approach which relies on sampled data and big sound buffers will just not work. Therefore we need to rely on playing the generated sounds as directly as possible. A Synthesizer is an electronic musical instrument that generates audio Read more…

The Most Beautiful Radio Music Player for the ESP32

In the last couple of blogs I was setting the stage for my Radio Music Player for the ESP32. I was thinking first that I will use one of the many existing web based music applications together with my ESP32 Bluetooth Player. But I soon realised that either they want my money or bombard me with annoying commercials! My GUI was written with Vue.js and I am using radiobrowser-api-rust to find the Radio Stations – Read more…

Progressive JavaScript Frameworks with Microcontrollers (Vue.js on ESP32)

The ESP32 can provide the functionality of a Webserver. There are plenty of examples where this functionality is used to provide a GUI to control the Microcontroller or to provide information from it. What all have in common: they is very basic and often plain ugly. Therefore the question is, how to run a modern Progressive JavaScript Frameworks together with an ESP32 in an easy way. Unfortunately it is out of the question to put Read more…

A Simple Arduino Bluetooth Music Receiver Library for the ESP32

The ESP32 provides a Bluetooth A2DP API that receives sound data e.g. from your Mobile Phone and makes it available via a callback method. The output is a PCM data stream decoded from SBC format. The documentation can be found here.  I2S is an electrical serial bus interface standard used for connecting digital audio devices together. It is used to communicate PCM audio data between integrated circuits in an electronic device. So we can just Read more…

Music from a Raspberry Pi over I2S

The simplest way to stream music from a Raspberry PI to an external amplifier is to connect the headphone jack to the AUX Input of the amplifier with the help of a corresponding connector cable. From a quality point of view a better approach is to use an external Digital to Analog Converter (DAC)  connected to the I2S pins of the Raspberry PI and for a PI Zero this is the only way because it Read more…

Music from a ESP32 Microcontroller

When I moved to my new place in the beautiful canton of Valais – I did not re-activate my old Turntable and Amplifier and just left them in a corder. Today I decided to reactivate my devices again but to my disappointment I could hear only some scratching sounds form my loudspeakers when I turned the different controls. I took my Technics SU-Z2 amplifier apart, cleaned it from the dust and applied plenty of Contact Read more…

OpenSCAD Libraries and Change Management in the Jupyter Kernel

Im my last Blog I was using some functionality from https://dkprojects.net/openscad-threads/ in order to define a nut and a bolt. I was finding this library with the help of Google. Like with any software language, it does not make sense if you try to re-invent the wheel (though some key stakeholders of the project actually think that everybody should write their’s own library). In any case it is worth to check out if some components Read more…

The Cheapest Camera for Octoprint

I bought myself a cheap Ender3 3D Printer. As my first project I decided to connect it to Octoprint. Because I did not want to use any of my Raspberry PIs and I had a spare old FitPC2 Linux machine, I thought it was time to reactivate it for a new purspose. I am using this solution successfully for quite some time now, so I wanted to take it to the next level by adding Read more…