Hardware I was receiving my ordered SD module but I was struggling a bit to connect it to my ESP32 via the SPI interface. I double checked the connections to make sure that I was using the right SPI pins, no change! I reformatted the SD drive again using FAT32. This did not help either! Finally I got it to work when I connected VCC to 5V instead of 3.3V – I should have read Read more…
For one of my current projects I had a closer look into the HTTP Protocol. Usually you might use a separate library for doing http calls from Arduino (e.g. with an ESP32) but if you are low on memory, you might get away without this by just using the WiFiClient: Setting up a WiFi connection On an ESP32 you would e.g. do the following: First you need to connect to WiFI and then you can Read more…
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…
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…
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…
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…
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…
Im my last post I was describing how to set up BlueAlsa on a Raspberry PI to use the PI as a a2dp source. Unfortunatly this is a little bit more complicated in Armbian because the project is not available in a Respository. Fortunatly I found some instructions created by guidol
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…
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…