From WordPress to a Static Website

WordPress plugins such as the Simply Static and others have the ability to automatically convert each of the WordPress pages and posts into static HTML files. I tried it in my environment but without any convincing result: When I double checked, the exported pages did still contain URLs which were pointing to the server, so on first sight everything seemed to work, but if you switch off WordPress the exported files stopped to work as Read more…

Ranting against C++

When I was in University 40 years ago, I was a big fan of C++. However I never had the need to do any projects in this language so far. I did plenty of work in ABAP, Java and later on enjoyed the relaxed approach on the usage of semicolons in Javascript and I also did some work in Python. That changed when I discovered the world of Microprocessors and Arduino and I used C++ Read more…

C++ Lambdas in Arduino

I had the need to pass some callback functions to some of my generic C++ Arduino classes. So I was asking myself if we can use Lambdas in Arduino. Here is a small test sketch, to verify this. #include “TestLambda.h” void setup() { auto f1 = [](int number) { Serial.println(number); }; LambdaTest t(f1); t.callLambda(123); } void loop() { } And here is the related TestLambda.h content: #include <functional> class LambdaTest { public: LambdaTest(std::function<void (int n)> Read more…

Accessing Remote Files from an Arduino (with FTP)

I was looking for a Arduino library which would allow me to access remote files on a Linux server. Unfortunately I did not find anything that I liked. So I came up with my own solution which is based on FTP. The FTP protocol is one of oldest communication protocols: It is easy to implement and therefore rather efficient and you can find plenty of free server implementations on all platforms. The library provides a Read more…

Jupyterlab and C++

Today I tried to create a Dockerfile for XEUS-Cling in Jupyterlab. The challenge was, that the installation is done with conda which is a little bit tricky to use together with Docker. After some unsuccessful trials, I finally came up with the following working solution: FROM continuumio/miniconda3:4.8.2-alpine MAINTAINER phil schatzmann USER root RUN apk add –no-cache bash SHELL [“/bin/bash”,”–login”,”-c”] ENV PATH /opt/conda/envs/cling/bin:/opt/conda/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin RUN conda create -y -n cling xeus-cling xeus-python jupyterlab -c conda-forge WORKDIR /home/xeus-cling Read more…

Playing a Synthesizer to a Bluetooth Speaker using a Raspberry PI Zero

I was asking myself if I can use a headless Raspberry PI Zero together with a MIDI keyboard as simple Synthesizer which sends the sound via A2DP to a Bluetooth Speaker. So technically speaking I wanted to set up my PI as a2dp source. Installation Initially I tried to do the setup with Pulseaudio. However it seems that there are plenty of issues with this option, so I decided to use ALSA instead and removed Read more…

The Synthesis ToolKit (SKT) Library for the Arduino ESP32 – Bluetooth Support

I made the Synthesis ToolKit (SKT) available as Arduino Library. The Synthesis ToolKit in C++ (STK) is a set of open source audio signal processing and algorithmic synthesis classes written in the C++ programming language. STK was designed to facilitate rapid development of music synthesis and audio processing software, with an emphasis on cross-platform functionality, realtime control, ease of use, and educational example code. I have demonstrated the MIDI Bluetooth functionality where we can receive Read more…

The Synthesis ToolKit (STK) Library for Arduino – Lessens Learned

Overview The Synthesis ToolKit in C++ (STK) is a set of open source audio signal processing and algorithmic synthesis classes written in the C++ programming language. You can find further information in the original Readme of the STK Project Like many other sound libraries it originates from an University (Princeton) and can look back at a very long history: it was created in 1995. In the 90s the computers had limited processor power and memory Read more…

The Synthesis ToolKit (STK) Library for Arduino – Running on a Nano

I made the Synthesis ToolKit (SKT) available as Arduino Library. The Synthesis ToolKit in C++ (STK) is a set of open source audio signal processing and algorithmic synthesis classes written in the C++ programming language. STK was designed to facilitate rapid development of music synthesis and audio processing software, with an emphasis on cross-platform functionality, realtime control, ease of use, and educational example code. Today I was investigating if the library can be used on Read more…