Photo by Maksym Kaharlytskyi on Unsplash

This is an overview of all my posts, apps and other code I have published so far.

It is basically an overview for myself of what I have written in the past and also serves as an index in case I quickly need to look up something.

I mainly cover these topics:

  1. My iPhone Apps

If you like my work and find them helpful feel free to support me.

This document will be updated whenever I publish a new article. …

A Practical Introduction to CoreMIDIF

This post is a programming tutorial on how to receive MIDI messages on your iPhone, iPad or Mac with your own code. It will provide a code walk-through and a downloadable Xcode project with a complete working example.


On the 26th of August 2013 I have bought a Roland A-88 MIDI controller. I honestly thought I had the time to teach myself to play the piano.

Being notoriously curious about things I have asked myself “What is MIDI and what comes out from that controller?”. Yes, I could have walked the easy way and just downloaded an app, but …

First Steps with Kubeless on k3s

Photo by Greg Rakozy on Unsplash

It is time to go serverless, at least for me. As a developer I want to write application code and get it running “somewhere” as quick as possible.

I don’t want to switch hats during development just to get my code into some cloud by creating new Docker images and changing some Kubernetes configuration.

Yes, of course, I could setup some CI system, but sometimes this is a bit too much in a local dev-environment.

The serverless paradigm goes into the right direction in my opinion. Time to get a feel for it.

I have chosen Kubeless as a framework…

Image: Apple

This post provides an overview about all Swift Concurrency related topics presented at this years WWDC21.

As WWDC21 is still in full-speed, more and more session are popping up that elaborate on my favourite topic for this year: Swift Concurrency.

Concurrency and asynchronous code is one of the topics I regularly have to deal with since I have started to write code many years ago.

It is also one of those programming related topics where I had to bang my head the most against a wall. …

Apple WWDC 2021 (Image: Apple)

Although I have tried to note down everything that has been presented, it is likely, that I have missed a point here and there.

Still, I find it a pretty impressive list considering it has been presented in under two hours.

You will find all topics in the chronological order as they have been presented.

My top three updates:

  • Concurrency in Swift

Feel free to buy me a coffee if you like this post.


  • Spatial audio: Voices are spread out

Integrate a Barcode Scanner into your SwiftUI-App

Barcodes are everywhere and thanks to Apples extensive frameworks, we have everything to make barcode processing an easy task.

This article provides everything that is needed to include barcode scanning into an iOS application that is based on SwiftUI.

Apart from being a SwiftUI-application, two other frameworks are being used in this tutorial.

First, there is AVFoundation, which is described in Apples developer documentation as follows:

Work with audiovisual assets, control device cameras, process audio, and configure system audio interaction.

Second, we are going to use the Vision framework:

Apply computer vision algorithms to perform a variety of tasks on…

A Tutorial on CoreLocation

Photo by Sylwia Bartyzel on Unsplash

This post is a tutorial on how to retrieve the geographical location of an iPhone or iPad by using Apples CoreLocation framework.

I first walk through all the steps necessary to setup a listener for changes of the devices location.

At the end of this post I will wrap everything into a handy Combine Publisher.

Feel free to buy me a coffee if you like this post.

The LocationManager

The main class that does all the work is CLLocationManager. Let's instantiate one.

private let locationManager = CLLocationManager()

A delegate is needed that will receive the location updates.

self.locationManager.delegate = self

The delegate…



This part integrates DJIs UX SDK into our sample SwiftUI app to provide situational awareness to the drone pilot and to improve the overall flight experience.

In the last 4 parts the foundation has been created to get the drone into the air. We have:

  1. setup our workspace,

One drawback was the user interface. …

Photo by Jesper Aggergaard on Unsplash

Every now and then I come across an SDK that is not using SwiftUI, but “the old” UIKit with its UIView and / or UIViewController.

As I am in the process of writing a series on programming DJI drones, I am using DJIs SDKs which are based on UIKit. Therefore I had to find a way on how to use them in my app that is based on SwiftUI.

This post explains how to use UIView and UIViewController with SwiftUI-apps and provides some "cut-and-paste"-ready blueprints.

Feel free to buy me a coffee in case you like this post.

Integrating a UIView

In case…

The AppDelegate Is Back

Photo by Cenk Batuhan Özaltun on Unsplash

There is no need any more to explicitly create an AppDelegate with SwiftUI’s new lifecycle. There might be situations though where an AppDelegate might still be required. This post explains how.

This post is a follow-up on my first post “How I Start A SwiftUI Project”.

While creating an app for my tutorial series “Programming DJI Drones”, I ran into a strange problem.

My app was behaving non-deterministic, every coders nightmare. Sometimes it would work as expected, and sometimes not. I have explained all details in this post on Stackoverflow.

I could only make it work to re-introduce the “good…

Tobias Wissmueller

Documenting my Tech-Stack

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